Most of you are now aware of the summer defoliation of eelgrass in
Chesapeake Bay late last year that resulted in all areas of the bay (as
well as many areas in the coastal bays) devoid of eelgrass by fall, an
event not observed in the last 30 years. We have attributed this event to
the hot and still weather conditions last summer when water temperatures
exceeded 30C, a lethal temperature for eelgrass meristems. Cursory surveys
last fall found a few areas where some adult plants survived and seedlings
were also being observed. However, we all felt we had to wait until this
spring to get a better sense of the outcome of the event.
So far there appears to be both good news and bad news from observations
this spring. The 'not so good' news comes from both an overflight I made
on April 7 from a Cessna at 1500 ft of many areas of the lower bay, the VA
portion of Chincoteague Bay, and VA's lower seaside bays, as well as ground
surveys being made by my staff and Ken Moore and his student Jessie
Campbell. I've attached a pdf showing the flight path I took (a composite
of SAV coverage from these areas is shown in green). At this time of year
one would expect to easily see dense beds in many areas. I saw very little
that could be considered dense. Most areas basically appeared
unvegetated. Of the few areas I observed that may have had grass, I would
have classified most as a category '1' (01-10% cover) and some maybe a '2'
(10-40% cover). I could not determine what contributions widgeon grass,
which co-occurs with eelgrass in these areas, may have made to any of these
cover categories. Some areas had a slight discoloration to the bottom that
did not look like 'grass' and may have been the old rhizomes which have not
washed out yet. This was very evident in the Coards Marsh area of
Chincoteague Bay (Quads 175, 172). The only areas I saw that clearly had eelgrass
present were in the Hungers Creek area of the bayside (Quad 124) and two small areas in
the lower York, each no larger than an acre. I was surprised that the
densest beds I observed on the entire flight were our restoration plots in
South and Cobb bays (Quads 212, 184), the two seaside bays that we have been working in
Now the good news. Our field surveys are showing seedlings in all areas we
have been ground checking. These are still small (1-4 shoots), but growth
should increase rapidly in the next few months such that dense areas of
seedlings may be visible in the aerial monitoring later this spring. We
surveyed two areas of the lower bay where we have been monitoring propeller
scars and recorded an average of 18 seedlings per meter squared (range of
3-48) along the Poquoson Flats area and 8 seedlings (range of 1-25) in the
Browns Bay area of the Mobjack Bay (Quads 131, 141 ). We have found very few adult plants at
these locations and thus most of the recovery process is going to be fueled
by seedling growth. There is one downside to this observation. With few
adult plants, there will be even fewer flowering shoots and an extremely
small seed crop produced. In the plots where we measured seedling numbers, we
found an average of 0.1 to 0.2 flowering shoots per meter squared. Normal
densities at this time can range up to several hundred! These low
densities of adult shoots for Chesapeake Bay beds contrasts with more
significant numbers of adult shoots and flowering shoots we observed last
Monday (April 10) in the South Bay restoration site (no data collected due
to the low body core temperatures of my staff and I that day when we got to
the site following many hours counting seedlings at another site).
Over the next few weeks, we will be field checking additional sites to add
to our data base above. We will keep you posted on these observations.
05/10/06 Bob Orth, VIMS
Here's the latest update on the eelgrass situation from recent field
observations and low level aerial surveys.
I made a second aerial reconnaissance on April 20 (flight path). The majority of the flight covered the western shore from the
Back River up to Reedville but I also covered some of the same areas I flew
over earlier along the bayside eastern shore. MD DNR staff also made a low
level aerial survey about the same time, primarily in the MD section of the
mid-bay and Chincoteague. The observations from these two aerial surveys
showed that most areas have very sparse beds, although where SAV is present
it appears to be getting denser, as I could see more patches than
earlier. The dense beds of recent years around Poquoson Flats and Mobjack
Bay are depressingly sparse, as are many areas along the bayside lower
eastern shore(Quads 131, 132, 141). In the mid-bay area the previously dense areas around the Little Annemessex River and Great Fox Island and parts of the big bed
between Tangier and Smith were really sparse (Quads 099, 100, 101, 107). Surprisingly, some of the densest beds were noted in the Big Annemessex River and along its north
shore going towards the Manokin (MD's observation) (Quads 085, 093).
The numbers of field observations are beginning to increase and are
confirming some rapid growth of eelgrass seedlings that were noted
earlier. But in these areas, the number of flowering shoots is very low,
in some cases less than 1 per square meter compared to the several hundred
per square meter that we are used to seeing. Ken Moore has reported
excellent seedling growth covering up to 30% the plots in his Goodwin
Island NERRS transects (mouth of the York River) (Quad 140). The NERRS site at VIMS
also shows excellent seedling growth but few flowering shoots. Scott
Marion went to Dameron Marsh (just below the Potomac River near Reedville)
and noted some really good eelgrass growth and survival of adult plants
through last summer (Quad 106). He noted many more flowering shoots (up to 40 per
square meter) than at sites that died off. Lee Karrh field verified beds
in the Big Annemessex River and indeed found more eelgrass than I would
have expected. Surprisingly, the bed just at the mouth of the Big
Annemessex was eelgrass, and had some of the densest concentrations of
flowering shoots of any place he checked (Quad 093). Unfortunately, those big, lush
beds in the Little Annemessex river where DNR mechanically collected
"heaps" of flowering shoots the last two years is gone (Quads 100, 101). Seedlings are
present, but almost no flowering shoots. Jacques van Montfrans (VIMS) was
at Cherrystone Inlet last week and found some dense patches of eelgrass
with healthy flowering shoots, but the bigger beds near the campground were
not at all what we have seen earlier (Quads 133, 134). Staff and students working with
Emmett Duffy at VIMS reported some healthy stands of eelgrass in Back
River, near Langley AFB, with many more flowering shoots (Quad 147). This was one of
the areas that had a significant amount of eelgrass remaining in 2005. The
MD DNR group has reported that eelgrass in some of their 2004 restoration
plots off Cherryfield Point in the St Mary's have survived the 2005
defoliation, as they have observed larger patches with flowering
shoots (Quad 080). That is pretty impressive!
The picture from the seaside is both good and bad. The big beds in
Chincoteague appear to be really down based on what we have seen from the
air (Quads 170, 171, 172, 173, 174, 175). Lee Karrh has found some of the healthier populations up around
Tingles Island (Quad 170). However, Eva Koch, who has established a Seagrass Net
transect off Tizzard Island, noted that it was essentially unvegetated with
few seedlings and only had flowering shoots at her mid-depth transect
(about 2 per square meter) (Quad 172). Farther south, in the VA southern seaside
bays, eelgrass in the VIMS restoration areas in South Bay appeared quite
healthy as of Friday with many more flowering shoots than any place in the
lower bay (Quads 184, 212). Just north of South Bay in both Cobb and Spider Crab bays, the
planted eelgrass beds also appeared quite healthy; and a recent check of
our test plots in Hog Island Bay, the next bay up, found them doing
well (Quads 184). We also found more naturally recruiting eelgrass patches with
flowering shoots in Hog Island Bay, in the vicinity of those discovered in
A potential issue on the horizon could be the reappearance of "wasting"
disease in the coastal bays. Both Lee Karrh and another observer reported
"blackened" patches on numerous leaves in a couple of locations in beds in
north Chincoteague (Quads 170, 171, 172, 173, 174, 175). These patches bear close observation over the ensuing
I'll continue to provide updates when additional information is
available. The aerial survey for 2006 will commence in the next few weeks
so we will have a much better and quantitative picture of the extent of the
In summary, there seems to be more places than we previously appreciated in
which at least some adult plant survived the defoliation. The most notable
areas are in the mid-bay regions. In addition, the widespread abundance of
seedlings (and their already significant growth) is likely to result in
substantial observable grass beds by June. Finally, flowering shoots are
significantly reduced or even absent in most locations, reflecting the
dieback of adult shoots, which will have consequences for seed production
and subsequent seedling recruitment into next year's population.
05/10/06 Peter Bergstrom, NOAA
Here is what we found on in SAV surveys Mon and Tues:
Kayaked about 8 miles with Shelby Laubhan. Found scattered small
patches of horned pondweed (Zp), about average abundance or perhaps a
bit less than average. Found a few scattered short redhead grass (Ppf)
plants, about where I expected except I could not find any at South
Ferry Point, and they were very sparse at Ulmstead Pier (Forked Creek).
Most redhead was very short, 3-4" long, and most horned pondweed was
also about as short. Only patch with SAV density > 1 was in the
downriver "corner" of Swan Cove (see attached map), mostly Ppf with some
Zp where density was about 2. We found no wild celery at South Ferry
Point where it usually occurs; it may not be up yet there. Surface
salinity (with refractometer) was 9-10 ppt. Last Sat with meter,
surface salinity was 7.3-8 ppt (7-9 ppt by refractometer at the same
stations so it can read higher than meter), and bottom salinity was
8.5-8.6 ppt, at Old Man, Cattail and Forked Creek. Forgot Secchi disk
on Monday but it appeared to be <= 1 m (on Sat. it was 0.7-1.15 m). Low
tide never happened due to upriver winds and possibly an offshore storm.
See maps of where I found redhead grass in this part of the
Magothy last September, and what we found on Monday (Magothy 2005, Magothy 2006). As you can see we
were looking on Monday in places where redhead was common last September,
but did not find much. It may simply not have been up yet; hard to say.
SevernRiver (Quads 023 ,024, 031) (Tuesday)--
Took it easy in Fred Kelly's power boat (he is the Severn Riverkeeper);
Howard Weinberg joined us. Secchi was 1.4 m in Saltworks Creek, salinity
10 ppt with refractometer, and it read 12 ppt in the river. We found
scattered redhead plants next to the boathouse outside Rays Pond, and
they were longer than the Magothy plants (5-6" long) but still very
sparse. There was also sparse horned pondweed, and some of these were a
bit longer than the Magothy plants as well. All of these beds were
density 1. We headed north towards Asquith Creek and in the large bed
that appeared in 1994 there were clumps of Zp and Ppf and once clump of
old Ppc (with clear bayonets) that looked like it overwintered. Based
on what I could see through the water (the "low" tide was not very low
as on Monday, Secchi was visible on the bottom in 0.8 m) the density was
about 2. We crossed to Sherwood Forest, between Brewer Creek and the
main Sherwood pier, and found a small but dense, long, and very green
clump of sago pondweed that was to the surface.
[NOTE--This was very atypical sago (very robust with wide, shiny leaves
for sago) but luckily I had seen a similar form before, in Muddy Creek
which drains into the Rhode River through the SERC property, also in
May. Both had marked, clear bayonets and the SERC plants had tubers
attached to them so they were definitely sago. (I have photos from both
sites if you want to see them). Perhaps when sago comes up in May from
tubers it looks different?]
A bit upriver, towards the main Sherwood pier, we found some taller,
larger and denser patches of redhead, sago and horned pondweed that were
clearly visible from the boat. The densest parts of these had density 4
within the clumps and density 3 over the whole area. See map (Severn 2006).
In terms of species shifts this may cause, I expect less Elodea (Ec)
and Vallisneria (Va), and more Stuckenia (sago pondweed or Ppc), in the
Chester and Magothy this year. The Severn lacks the first two species
but should have more sago. In terms of likely changes in SAV area in
2006, it went up in 1995 in all three rivers, and went up in 2002 in the
Magothy and Severn but in the Chester in 2002 it stayed at a low level.
In 1999 the Magothy & Severn surveys were incomplete due to Hurricane
Floyd, and in 2001 both surveys were incomplete due to the airspace
restrictions after the terrorist attacks. In the lower Chester, SAV
area fell in 1999 and was 0 in 2000, and rose only a bit in 01-02, not
recovering until the drought was over in 2004.
Thus my best guesses for 2006 SAV area in these 3 segments are a drop
in SAV area for the lower Chester (and possibly other segments to the
north such as the Gunpowder with a lot of Ec and Va, depending on their
bottom salinity levels) and a modest SAV increase in the Magothy and Severn.
Spring SAV in the Potomac River:
We have made observations in the fresh and oligohaline Potomac from DC to Nanjemoy. We found 8 species. We are expecting SAV to do well this year in the lower fresh and upper oligohaline Potomac since beds are already going strong, hard to tell about the upper tidal fresh and lower oligo because those species at those observation points may just be slower to emerge.
I went on a canoe trip at Smithsonian Environmental Research Center (SERC) yesterday (5/21) in Muddy Creek (drains to Rhode River) and there were more grasses than I had seen in the same area in past years, even though it was near high tide. As before we found Sago pondweed, which was wider and more robust than what one usually sees elsewhere, but I'm sure it's sago; it has clear bayonets and last year I pulled up a plant with a tuber attached to the roots. No flowers or seeds, though. At the confluence of the N & S branches, just up the creek from the canoe launch, sago was visible in the murky water at high tide, so it must be quite visible at low tide. We also found milfoil (some visible at high tide) and some short horned pondweed (not visible,found only by raking). These are the same 3 species we found in 2004 and 2005 in the same vicinity. See map of what we found where yesterday. The 2004 observations from Muddy Creek by myself and SERC staff are online here (bottom center of the map): http://www.vims.edu/bio/sav/sav04/quads/sr030_page.html
Salinity at the fish weir was 10 ppt by refractometer, higher than usual, as it has been elsewhere. In 2004, salinity in Muddy Creek was 0-0.1 ppt, and reached 6 ppt in Boathouse Cove; in 2005 I did not record salinity. I forgot my Secchi disk this year but the Secchi depth there was 0.25-0.4 m last May, and appeared to be similar yesterday.
We got a good preview of some of the early growing species of SAV in the Potomac. I drew the beds on a basemap as we flew from Anacostia to Quantico, both sides of river. See those drawings of SAV distribution (Map 1, Map 2, Map 3). I noted the time as we flew, and when we have some time, we hope to match photos with location using the time stamp on the digital photos.
Over the last two weeks my students and I have been checking SAV at
various locations in the St. Mary's River, MD. On May 25, we checked
several locations. Northwest of Tippity Wichity Island, we found a dense
and extensive bed of horned pondweed (Zannichellia palustris). Plants
were in flower and were up to a meter tall. Temperature was 21.6 C,
salinity 11.8 ppt, oxygen saturation at the surface was 91.5% and at the
bottom in a dense bed 34%. Moving downstream we found patches of widgeon
grass (Ruppia maritima) between Martin and Horseshoe Points (Temp 20.9 C,
Sal 13.8 ppt, Secchi 1.2 m), with some flowers. At Chancellor Point we
found a dense bed of widgeon grass with flowering shoots (Temp 19.8 C Sal
14.1 ppt, Secchi 1.8 m). We also found widgeon grass beds across the
river on the north and sound side of Windmill Point. On a previous trip we
had noted that the large bed of widgeon grass at Rose Croft Point still
persists. At the mouth of St. George Island we observed extensive widgeon
grass beds at Russell Point and just west of Price Cove, again with lots
of flowering shoots. There were patches of widgeon grass on the east of
Price Cove, but these patches were less dense and had fewer flowering shoots.
On May 25 and again on May 31 (Temp 24.1, Sal 13.6 ppt, Secchi to bottom
at 1.1 m) we surveyed the area at Piney Point planted last fall with
eelgrass (Zostera marina) by the Woodrow Wilson Bridge Project. Survival
of the transplants is high, and the transplants have propagated
vegetatively to form patches of eelgrass, some of which are starting to
merge. Many of the patches have flowering shoots. While the flowering
shoots and older leaves of vegetative shoots are covered with small
barnacles, most vegetative shoots have new healthy leaves that are
barnacle and epiphyte free.
On June 1, I kayaked along the shore north of Chancellor Point and found
patches of widgeon grass with some plants in flower. On June 2, I kayaked
into Chicken Cock Creek and found a few small patches of widgeon
grass. There was little evidence of SAV along the shore of the St. Mary's
River south from Chicken Cock Creek. Later that day I snorkeled behind
the rock breakwaters at the Webster Field naval base. In the area that
eelgrass was planted a couple years ago, I found 5 small patches of
eelgrass, none of which was in flower. I also found patches of widgeon
grass and horned pondweed, both of which were in flower. In this area
there were large mats of drifting seaweeds that included Enteromorpha and
filamentous red algae.
I got back to Webster Field last Friday to check to see if any eelgrass
recovered from last year and also to check the NOAA SAV planting
sites. The good news is that I did find five small patches of
eelgrass. There could be more but the visibility was not great and there
was a huge biomass of seaweeds (Enteromorpha and filamentous reds)
covering much of the bottom. None of the eelgrass was in flower, but it
did look healthy. There was no sign of any of SAV in the areas that were
planted as part of the NOAA restoration day. In other areas there was
both widgeon grass and horned pond weed.
I led a group of SAV Hunters on Marshy Creek
on 6/8 using canoes provided by CBEC. It's a great spot to learn to tell
some of the confusing species of mesohaline SAV apart, and you can rent a
canoe or kayak there for a small fee. You need to make a reservation
(call 410-827-6694 or e-mail email@example.com), see
http://www.wildfowltrust.org/index.htm for directions). I would check the
tide tables to go at low tide (Kent Narrows is the closest tide
prediction, see http://tidesandcurrents.noaa.gov/tides06/tab2ec2c.html#47 for list), and try to avoid evenings when thunderstorms are more likely.
In most recent years, when the grasses are fully grown, it can be hard to
paddle through some of the dense beds at low tide (but they are not that
tall yet this year). The salinity was higher than usual on 6/8 due to low
rainfall, 14 ppt, and there were already small sea nettles. The water
clarity was good for the summer, 1.1 m, probably partly because there had
not been any rain for a few days. The tides were about 1 foot (0.3 m )
above normal, and the plants were still short, so it was hard to see the
plants in spite of the decent water clarity. We found six species: horned
and sago pondweed; redhead and widgeon grass; milfoil; and Elodea. We
found a lot more sago pondweed than we found here in past years, and it
was the fairly robust variety, with longer and broader leaves than what
is more common elsewhere--similar in form to what I have seen in Muddy
Creek on the Rhode River and in the Severn River (see photo of
the latter, unfortunately the bayonet is out of focus). The sago had no
flowers or seeds but the clear bayonets were well defined, and the only
widgeongrass we found was the short form (it tends to come up more slowly
than sago pondweed). It is possible that there was the same amount of sago in past years,
but it was hard to see because we looked later in the season and the other species were taller and denser then. It could also be that there really is more sago this year, due to the higher than normal salinity. In past years when I visited I found mostly the same species, except I found no Elodea there
in 1997. See the map of what species we found where, and a photo of
what I think was Nuttall's waterweed Elodea nuttallii (because the
salinity was so high). The lower salinity Elodea canadensis is usually
more robust and bushier. The new SAV guide coming out next week will be
the first Chesapeake guide to mention the two species of Elodea, although
when it went to press, we did not have any photos that we were sure were
of one species or the other. Growing at 14 ppt, I think this one must be
Nuttall's, and it resembles the drawings of that species in Brown & Brown.
I visited the marina at Millard Tydings Park in Havre de Grace on
Sunday, 6/11/06. I did not have a boat so I was limited to using a
throw rake off the bulkhead, but I was pleased to find visible beds
containing 7 species, a sizable portion of the species usually found in
Susquehanna Flats. Secchi depth was only 0.5 m and salinity was about
0.5 ppt with a refractometer. The SAV species I found were curly
pondweed Pcr, Spiny naiad Nm, Hydrilla Hv, milfoil Ms, water stargrass
Hd (one small piece), wild celery Va (a few dense beds), and coontail Cd
(one dense bed). Several people were fishing in and near the Va/Ms bed
labeled #16. See map.
I have to date only seen SAV to the surface in Fairlee Creek
around Great Oak Marina. I also have some small patches of horned
pondweed in one creek in the Chester, but they wouldn't be readily
visible from the air. I normally don't begin survey until late June
early July. On a related note, salinity at my station on Eastern Neck
(Durdin Creek, Quad 026) has pushed up to 13-14 ppt, undoubtedly due to the lack
of significant spring rainfall. It had been averaging around 10 ppt
for the past couple of years. The last time time salinity pushed up
and stayed up this high there was a significant SAV crash in the lower
Chester that growing season.
I went out to go crabbing this morning, which I usually do by working the
eel grass beds at low tide. It was a very disappointing trip not so much
because I did not get any crabs. It was more a case of no grass beds. Historically, (at least the past 10
years) there have been good grass beds just outside of the mouth of
Roberts Creek (which is a small creek between Poquoson River and Bennets
Creek). Also, there was historically a nice stand of eel grass on the sandbar
that juts across the mouth of the Poquoson River at Hunts Point. Also,
there were historically several small stands of eel grass in between the
sand bars just South of the mouth of Roberts Creek.
This year's report. NO stands of sea grass were observed in any of the
above locations. I saw an occasional section of grass the size of a
dinner plate on the inshore waters near the mouth of Roberts Creek. I saw
no grass (even small patches) in between the sandbars south of Roberts
Creek. I saw no major grass beds on the flat across the mouth of the
Poquoson River at Hunts Point. I did not walk this last area so I do not
know if there were any small patches of grass in that area.
I had the opportunity today to do some surveying in the Upper Chester
(above the bridge) and found some small patches of millfoil on both the
Kent and Queen Anne's sides just above a line from Buckingham Rd. (Kent
Co.) to Possum Pt. (QAnne's Co.)~ lattitude 39 deg-14.2min N /long
76-deg 0.5min W. and below Foreman Branch. The densest patches were on
the Kent side just above the public landing on Buckingham Rd. This was
one of the two areas SAV was present last season in the upper Chester.
I looked for SAV via kayak on 6/22/06 at low tide on Saltworks Creek and
the adjacent Martins Pond, on the Severn River (MD). I was helped by
Allison Albert, who is working for the Severn Riverkeeper, Fred Kelly
this summer, and a volunteer, Sophia Kim. Secchi depth was moderate
(0.75 m) and salinity was fairly high for June (12 ppt), with many
medium sized sea nettles seen. This map shows what we found
where; arrows show where we found Ppu (one site), and the farthest up
the creek we found Ppf. We found 6 species, more than usual for a small
area of the Severn: Ms Zp Rm Ppf Ppc Ppu. Both the Rm and Ppc were
flowering--I think this was the first flowering Ppc (sago) I had seen
anywhere in the Severn or Magothy rivers (see photo of Ppc flowering
shoot). This was also the first slender pondweed (Ppu) I've ever seen
on the Severn (see photo); it seemed to be increasing the the Magothy
last year. In terms of distribution, species diversity decreased as we
went up the creek, until there was only Ms and Zp and then very little
SAV, and a few clumps of Zp where we had to turn around. It's
encouraging to see redhead grass (Ppf) spreading up the Severn Creeks,
since when it first spread in the Severn in the mid to late 1990's it
was mainly restricted to the mainstem of the river.
The two SAV species that I've never seen in the tidal Severn, that occur
in the Magothy and lower Chester where the salinity is not that much
lower, are wild celery (Va) and Elodea (Ec). Va was mapped in the upper
Severn mainstem in 1979 near Plum Creek, but was not found in the Severn
in 1971-1990 point surveys, nor was Elodea. Those surveys turned up N
(naiads), C (Chara), and Cd (coontail) in the Severn, none of which have
been seen there recently. I've never seen Chara in the Magothy, and
naiads and coontail are very rare there. Either slender pondweed has
become more common, or the people doing the 1971-1990 MD surveys did not
recognize it often, because they only recorded it 4 times over all sites
and years, twice in Susquehanna Flats and twice in the Chester.
In 2005 I did relatively little cruising to places where there was SAV. At
the Osborn Cove Pier, however, after the Zannichellia died off, there was a
significant "patch" about 10 sq m, of Ruppia that appreared along the
sandbar. It "died back" with no remaining evidence and during winter I
thought that it had been scoured out by ice and wind-waves.
This was not the case, though very strong Zannichellia growth was very slow in
coming this season, it was a solid crop, now all dying off (eaten by the
Sea nettles I suspect) leaving the Ruppia, to my surprise.
There's a natural drift along the bar and "patch" has expanded some 4 1/2
m updrift to about 17 m sq. and apparently with seed pockets, about 42
meters down-drift, the patches totaling another 4 1/2 m sq. The patches
match the natural 2 m wind-wave sand cusps along the beach pretty
well, occurring at about 9, 11, 15, 18, 22 and 42 m away from the parent.
Overall this is approximately a 2.6 fold increase in Ruppia. I see vegetative bits
of Ruppia adrift in the creek. I suppose they're the colonizers, so this
must be occurring elsewhere. Interesting to see if you can spot this from
outer space when you fly the lines.
In the 1970s I "identified" Ruppia in the Cove, but suspect in my
ignorance it could have been Zannichellia. Ruppia was here in the late 50s - early
1960's because of finding it wound round the shaft of an old outboard
recovered in a shed here, stuffed there when the owner had a stroke.
Anecdotally, residents here in the 60's said SAV made swimming hard
because it wound round you all the time.
The SAV in the Potomac from Wilson Bridge (interstate 95) to Mount Vernon
is diverse (Hydrilla, Najas minor, Myriophyllum, Chara, Vallisneria),thick, green,
and healthy based on observations made from the shore or from wading at
low tide in areas accessible from the shoreline on July 1 and July 4, after
the extreme rain. Most species are at least 30 to 50 cm tall since emerging in
early June or mid May. Myriophyllum, abundant this year, was 1 - 2m tall by
early May between Quantico and Mount Vernon and probably elsewhere in the
Severn River (MD) volunteer data:
A. The graph shows a reverse salinity gradient in bottom
salinity from data I collected on Monday 7/3 with the Severn Riverkeeper,
Fred Kelly, volunteer Pierre Henkart who designed the monitoring network,
and other volunteers. They use YSI 85 meters which agreed well on DO
readings with my YSI meter and Winkler titrations (we did
comparisons). The lower bottom salinity was seen only at the two most
downriver stations (on the left in the graph), not at SR2/WT7.1 which is
just upstream of the US 50 bridge. The highest bottom salinity, 12.2 ppt,
was in Asquith Creek which also had more frequent anoxia than the other
stations (I measured DO = 0.0 mg/l there twice in the last month). I
suspect both patterns are due to its very narrow mouth and thus restricted
tidal exchange, restricted even further by the extensive, dense SAV beds
outside its mouth. B. Secchi depth showed a less pronounced mid-river peak
than bottom salinity, with the best clarity in mid-river off Sherwood
Forest (see graph; there are a few missing values I need to get).
C. On 7/3 the SAV beds outside Asquith Creek appeared to be as dense and
extensive as in past years, with many redhead grass flowers showing at the
surface. However, when I was there the tide was lower than normal, so I'm
not sure they would be showing on the surface at a more normal low tide.
D.There are also Severn salinity & DO data from 6/30 from the same
stations, that I am waiting to get from Pierre Henkart.
E. I collected some Secchi, DO, temperature and salinity data here in Spa
Creek at the end of our pier right after the rain and a few times since
then. The day after it stopped raining (Wed 6/28), Secchi depth dropped
to 0.3 m and the water looked brown, and bounced back to about 0.8-0.85 m
on Thurs and Fri. Surface salinity (@ 0.1 m) on Wed. was down to 5.0 ppt
which quickly rose past 10 as I dropped the meter, reaching 11.7 ppt on
the bottom, 3.2 m deep. By Friday surface salinity was up to 8.5 ppt and
bottom was down slightly, 10.3 ppt.
Magothy River volunteer data: A. We sampled 9 stations on Saturday 7/1 but I only have data from 3 of
the 9 stations so far. At the 3 stations for which I have data, there
was a reverse salinity gradient in surface salinity only, with 7.5 ppt in
Forked Creek and 8.0/8.7 ppt upriver in Cattail and Old Man creeks
respectively. Bottom salinity was 10-10.3 ppt at all 3 stations.
B. Secchi depths on 7/1 were better than what I measured before the rain
on 6/16 at Forked Ck (0.9 m), the same as before the rain at Old Man Ck
(0.95 m), and worse than before the rain at Cattail Creek (0.6 m). C.
Bottom DO was < 2 mg/l on 7/1 at all 3 stations, but that's fairly common
in the Magothy in the summer. One of the stations had bottom DO < 2 mg/l
on 6/1/6 and 2 had this on 6/3. Last year, all 3 stations had DO < 2
twice, on 8/18/05 and 9/17/05.
I have surveyed from the bridge at Eastern Neck Narrows (lat
39-03'-15.0"/long 076-13'-20.8") to just below Ingleside recreation (lat
39-02'-43.7"/long 076-14'-14.7") on July 9. Along the shore moving north
to south I found small patches of redhead grass and wigeon grass. At
Tubby Cove (lat 39-02'-51.8"/long 076-13'-19.9") there is dense growth of
a mixture of millfoil and redhead grass, with proportionally more
millfoil, with coverage in the 3-5 acre range. This pattern continues
southward into Calfpasture Cove (lat 39-02'-42.3"/long
076-13'-34.8") with coverage in the 8-10 acre range. Past the southern
edge of Calfpasture (lat 39-02'-50.7"/long 076-13'-38.8") there is a
dramatic decrease in coverage until at the end of the survey now growth
was found. In this portion of the survey growth was patches of redhead
grass, patches of wigeon grass, and patches of elodea, most of which was
not growing to the surface but had to be raked up. There was no evidence
of any offshore growth on the Bay side in the narrows at this
time. Secchi depths ranged from nearly a meter in the densest growth
areas to just under .5 m in open water. A water composite water sample
taken had a salinity of 5ppt.
Fairlee Creek: There is a bed of millfoil growing around the eastern
shore of Fairlee Creek (Great Oak shore) from lat 39-15'-48.1"/long
076-12'-15.4". The bed extends out from shore about 25-50 feet and is
patchy. Secchi depth .70m. Salintiy 5 ppt. Date of observation 06/28/06.
Swan Creek: There is a bed of millfoil growing around the southern shore
from Osprey Point Yacht Club (lat 39-08'-08.8"/long 076-15'-07.7") to
Spring Cove Marina (lat 39-08'-46.4"/long 076-14'-47.7"). The coverage
extends from shore out about 50-75 feet and is patchy. Secchi depth was
.4 m and salinity was 3 ppt. Date of observation 07/06/06.
As you all know, we are requesting a renewal of our 400 acre set aside in
South Bay in August. We are also hoping to get some additional area south
of this as part of the set aside
We went out yesterday to get some idea of just how far eelgrass has spread
naturally from the 400 acre set aside to give VMRC some idea of how the
eelgrass is doing and in the area they might add to the current 400 acres.
We ran 4 transects to assess eelgrass presence outside the set aside, two
that ran S-SW from the southern boundary, and two that ran west towards the
mainland from the western boundary. Conditions for this assessment were
not great as it was blowing S at 15-20 kts and a lot of the area was pretty
stirred. Never-the-less, the entire area within the set aside was pretty
clear as the grass is quite robust here and appears to be now just about
everywhere within this 400 acre area, providing the necessary structure to
keep the water clearer. There are numerous small to medium size patches
between the 48 one acre plots planted in 2001 and 2002.
The two southern transects were a little over 600 meters each and we marked
every meter where an eelgrass patch occurred. We were duly impressed
(actually pretty darn excited) about how much eelgrass there was south of
the set aside. We found eelgrass along the entire length of each of those
transects (just about every meter mark had a patch of eelgrass). Although
the patches were less numerous toward the end of those transects, these
distant patches were still large (approx 0.25 m2) and appeared quite
robust. And they went right up to the intertidal area where there are some
aquaculture leases. And all these patches had to have come from seeds
drifting from the area within the set aside!
The two western transects were interesting in that the one at the south end
had very abundant eelgrass in the first 300 meters and then patches all the
way out to 500 meters. Again, it was pretty exciting to see that much
natural recolonization. The other west transect, which was closer to the
north end of our set aside, had only 5 small patches over 300 meters. this
is quite intriguing as to why such a large difference in eelgrass abundance
between these two transects? It is possible it might reflect differences
in how the flowering shoots move when they break off and subsequently
disperse their seed in this region. It's also possible that the area could
have been dredged for clammed and any grass removed because this area is a
leased area for clam dredging.
In any case, it was an exciting day for all of us and these observations
bodes quite well for the continued recovery of eelgrass in these seaside bays!
ps - one interesting observation was the presence of a lot of birds feeding
over the grass bed at the inshore area of our set aside, diving for small
fish, which we could see in the area. I can't remember observing this
before. Is it possible that this is due to the grass supporting more small
The water up here in just about every direction is very turbid
though probably you are correct in that the Chester is nowhere near as bad
as the open Bay. I am also thinking from subjective observations that
this event was nowhere near as bad as Agnes, even though about the same
amount of rain fell (~10 inches). At that time the Chester was mostly
mud for a few days. and at no time did it appear as bad this year. I
think the fact that the event was spread over a week to a week and a half
instead of a day is partly to account. Also, two things have changed over
that time frame-now much of the acreage is conservation tillage of some
form, accounting for less sediment runoff, there are probably more grassed
waterways and buffers, and what stormwater controls there are in our urban
areas are no doubt better. Also, we now grow about half corn and half
soybeans, the later not requiring any nitrogen application. When Agnes
came in 1972 we were growing predominantly corn and the storm came before
the corn had incorporated much of the applied nitrogen. As far as
salinity goes, it looks like that won't be a worry for a while at least,
though we are still at just around even for rain for the year. I think
both last season and what I have seen of this season indicated some SAV
stress compared to the bumper crops of 2003-2004. I have been in the
upper Chester once, a couple of weeks ago, and there was some millfoil
around one of last years spots. It will be on my list of places to check
again in the next few weeks.
On July 16, 2006 I surveyed the river side of Eastern Neck from
Bogel's Cove to Shipyard Creek. In Bogel's Cove (lat 39-02'-14.7"/long
076-12'-41.4") there were patches of redhead grass and widgeon grass,
primarily along the south shore, extending out to about 50 feet, with
lesser amounts going around the western shore and very little on the
northern shore. In Durding Creek (lat 39-01'-54.1"/long 076-12'-36.4")
there was no SAV along the northern shore from the public landing up to a
point having lat 39-02'-02.1"/long 076-12'-57.6". At this point redhead
grass and widgeon grass began appearing in patches. Moving across the head
of the creek to the southern shore, the patches grew larger and more
numerous, with some sago pondweed and millfoil mixed in. As with Bogel's
Cove, the SAV primarily extended offshore 50 feet or so, and at only one
point along the southern shore was there a dense canopy, primarily of
redhead grass, maybe .5 acres in extent. In Shipyard Creek (lat
39-01'-37.2"/long 076-12'-34.6") there were small patches of redhead grass
along the north shore, beginning at lat 39-01'-36.7"/long
076-12'-43.7". Proceeding along the shoreline from north to south the
redhead grass became mixed with patches of sago pondweed and millfoil.
The southern shore had much less growth than the northern shore. As with
the other areas surveyed, the growth was along the shore, out to a
distance of 50 feet more or less.
Secchi depth in the vicinity of the densest growth areas in Durding Creek
was ~.6m. Immediately outside the growth areas the secchi depth was
.4-.45m. Salinity in the center of the creek was 6 ppt, compared to 10
ppt in the beginning of May, and 10-12 ppt earlier in the year.
Secchi depth in Shipyard Creek was .4m, with no noticeable difference
between growth and non growth areas, the growth being more sparse than in
Durding Creek. Salinity in the center of the creek was 7.5 ppt.
Compared to last year there is much less growth to date in these areas,
with Durding Creek (which has the greatest amount of coverage both years,
showing the greatest amount of change. There was very little elodea (an
occasional small piece could be raked up, none was seen at the surface)
and only small amounts of millfoil. Additionally, the growth appears
mainly along the shorelines with only a couple of small areas filled in.
07/18/06 Peter Bergstrom, NOAA
I don't visit the Eastern shore as often as the Western, but I spent 2
days accompanying Steve Ailstock and his staff on trips to look for seed
collecting beds of widgeongrass (Rm), and to plant some seeds at Barren
Island. We were hoping to find lots of Rm, but mostly documented
declines since the last few years.
Tred Avon (Quad 044) (7/11): Continued decline in Rm this year, compared to 2004.
Beds were large and dense enough for Steve to collect Rm seeds here in
the past; not so this year. The map shows we found Rm in the
mouth of Fox Hole Creek and in Flatty Creek, but only the grasses in Flatty
Creek were to the surface and flowering, and even there they looked a bit
thin. Waypoints 070 and 071 were both spots that had dense Rm in the
past but none this year; we had to go towards shore to 072 to find any
this year. There were few beds mapped here last year,
http://www.vims.edu/bio/sav/sav05/quads/ox044d.html but much more
extensive beds were mapped here in 2004 http://www.vims.edu/bio/sav/sav04/quads/ox044_page.html.
Barren Island (Quads 072, 073) (7/17): SAV declines here as well, and changes in
sediment. We went to Barren Island to check an area where Steve and his
staff had put SAV wrack last fall, and there was no trace of any plants
except for a few sprigs of Rm. See map for location. The
shallow area at the break in the island, enclosed by the breakwater, had
silted in since last fall, with about 0.3 m of new, very "fluffy"
sediment. They planted some new Rm seeds, but given the sediment type,
their growth seems unlikely. Secchi depth was only 0.3 m, water depth
was 0.35 m at low tide, water temperature was a balmy 31.2 C, and
salinity was 13 ppt. It appeared that the protected area had gotten
siltier a few years after breakwater construction, making it less
conducive to SAV growth, similar to what Evamaria Koch documented at
Bishops Head nearby. As we returned to the boat ramp, we saw a few dark
patches in the distance near shore, that were probably Rm, but the water
outside the channel was too shallow to check them out. This was
apparently greatly reduced from the SAV that was mapped along this
channel last year, when beds Q2 and IA3 were right next to the channel we
used (http://www.vims.edu/bio/sav/sav05/quads/hn073d.html) The beds we
saw were hugging the shore, near what was mapped as R1 last year. The
greenhead flies were memorable, as well as the heat!
Slaughter Creek (Little Choptank) (Quad 062) (7/17): Another continued decline in Rm
this year. This creek had a few dense Rm beds last year (see
http://www.vims.edu/bio/sav/sav05/quads/ty062d.html), and they were dense
and large enough in 2004
(http://www.vims.edu/bio/sav/sav04/quads/ty062_page.html) and previous years
(starting in 2002) for Steve to collect Rm seeds there. However, this
year we found only 2 sparse patches of short form Rm, with no flowers, in
two locations shown on the map. The cruise track shows where we
went, and we only found SAV at the 2 points marked.
This left Steve with hopes that the Potomac will have Rm beds with enough
seeds to harvest for his ongoing research; he said Tom Parham was looking
for them there.
I have been monitoring water quality in Durdin Creek (lat 39-01'54.1"/long 076-12'-36.4")
for a number of years at a dock just
inside the mouth of the creek. I have water clarity, salinity and water
temperature for the most part biweekly from about the year 2000. If I had
the acres of SAV in the creek, or the % coverage, I might be able to match
it up with these parameters and see what the significance of the
relationships are. I have my field SAV observations but they are somewhat
subjective, being taken from a kayak and not being able to see the entire
area at once. I think over that time period salinity bottomed out about
2002-2003 and water clarity maxed out at the same time, and that these
years had the best SAV growth. I also got to wondering recently if the
higher water temperatures the past two seasons were having any effect.
I surveyed the Upper Chester from lat 39-14'-37.3"/long 075-58'-42.0" to
lat 39-14'-10.0"/long 075-59'-51.3" on July 17, 2006. On the Queen Anne's
County side I was able to rake up some very short pieces of what appeared
to be hydrilla at the northeastern most part of the survey, in front of
the campground at Duck Neck. Other than this I found nothing on either
side of the river for the entire extent of the survey.
Secchi depth was ~ .25m and salinity was 0 ppt. The down river extreme of
this survey tied in with the upriver extreme of my survey in June from
Buckingham Wharf (in which millfoil was found on both shores) so that the
combined survey covers from Buckingham Wharf on the Kent side to Duck Neck
campground on the Queen Anne's side.
If you are still looking for flowering Ruppia, the Little Annemessex
River and the area around Cedar Island has extensive flowering beds
(http://www.vims.edu/bio/sav/sav05/quads/cf101d.html). I was in the area
on the 17th and was quite impressed at the extensive bed extending along
the northern shore of Cedar Island just west of Broad Creek.
Additionally, the southern side of Cedar Island, from Broad Creek to
Fishing Creek also has some dense areas of flowering Ruppia, with some
Zostera mixed in as well. This bed is not as continuous as the one on
the north side of the island.
07/24/06 Bob Orth, VIMS
The 2006 annual survey has begun and I've provided a summary below of what
we have noted so far for the lower bay as I have done in past years my
"first look" at the photography. Acquiring the 2006 photography has been
more of a challenge this year than ever before and it seems to get more
complicated each successive year. Winds, higher than predicted tides, fog
during the 2 hour sun window in the morning, TS Alberto and the "Big" June
rain provided the challenges to getting good photoraphy so far this
year. This year's survey of the lower bay SAV beds is particularly
important because it will provide the documentation needed to fully assess
the impacts of the 2005 eelgrass defoliation event. We, along with many
others, are very closely watching temperatures this summer given what we
observed last year. Most areas that experienced a serious dieback are
recovering with eelgrass seedlings, which did not produce flowering shoots
this year, and hence seed production this spring was either absent or
significantly reduced in many areas. Another very hot summer could be
The other event we are now following is the rainfall event at the end of
June which has left much of the upper bay above Kent Island covered in
quite turbid water even through this weekend based on what we see from the
MODIS satellite. Extensive field reports from Terry Willis of SAV in the
Chester River, which appeared to have less turbidity than the rest of the
upper bay, are still showing less SAV than in 2005. This may be due to the
higher salinities reported from that region in the early part of the season
(refer to MD DNR's Eyes on the Bay site for detailed environmental data
We continue to receive some interesting field observations from a number of
sources and have posted them on our web site under the 2006 field
observations (http://www.vims.edu/bio/sav/2006obs.html). As always, many
of these are from Peter Bergstrom and we appreciate the numerous detailed
notes. If you can find the time please share any of your observations with
us and the SAV community, as they are quite valuable in providing species
information that is important in understanding community dynamics.
THE 2006 SAV ANNUAL SURVEY Listed below are the locations in the lower Bay where we have acquired
photography for 2006. For those sections, I have listed the flight lines
that cover the areas and the dates they were flown. Please see our website
for a map of the lines that have been flown
(http://www.vims.edu/bio/sav/sav06/flightlineindex.html). Please note that
none of the beds noted here in the 2006 photography have been mapped or
digitized and these are simply my first observations from the photograph;
however, I have tried to give some reasonable estimate of how beds look in
2006 compared to 2005. Lastly, we have made some modification to our
program protocols and will begin processing the 2006 SAV beds in July with
the aim of having a bay-wide number by the end of February, two months
earlier than in previous years. It also means we will have a good idea of
the extent of 2005's eelgrass dieback in most areas by the end of the
summer. In spring 2006 we conducted an extensive ground survey of dieback
sites, and observed a large number of seedlings in many of the previously
dense beds. In some of these areas, robust seedling growth has resulted in
an observable canopy, however, in many areas seedling growth will be much
too sparse to be noted on the photography. Only where there are large
numbers of seedlings and where the growth is significant, will we be able
to detect SAV on the photography.
BROAD BAY (CB Segment LYNPH)
(Flight lines 102, 103 flown on June 14) (Quad 152)
SAV has been present in the past along a narrow fringe of the southern
shore at the entrance to the bay as well as a small area along the north
shore. There is no clear SAV visible on the photography, although several
field reports noted some seedlings in these areas. Other beds noted in
previous years along the north shore and along shoals at the east end
LYNNHAVEN RIVER (CB Segment LYNPH)
(Flight lines 102, 103 flown on June 14) (Quad 152)
No SAV was noted and none has been recently reported.
LITTLE CREEK (CB Segment LYNPH)
(Flight line 102 flown on June 14) (Quad 151)
SAV (both eelgrass and widgeon grass) has been present in the past just
inside the mouth adjacent to the amphibious base. The photography does
indicate some beds in this region in 2006.
DRUM ISLAND FLATS, POQUOSON FLATS AREA, including the BACK and POQUOSON
RIVERS (CB Segment MOBPH)
(Flight lines 96, 96a, 97, and 98 flown on June 14) (Quads 140, 141,
147). SAV completely defoliated and died in all these areas except Back
River in 2005. The photography and extensive field observations have shown
significant recovery in these regions in 2006. However, except for the
Back River where adult plants survived the dieback, it is all from seedlings.
LOWER YORK RIVER INCLUDING GOODWN ISLANDS (CB Segment MOBPH, YRKPH)
(Flight lines 93, 95, 96, 96a, 97 flown on June 14) (Quads 130, 131, 132,
SAV almost completely defoliated in all these areas in 2005. The
photography and quite a bit of field observations have shown significant
recovery in these regions in 2006. However, except for small areas near
Allens Island, it is essentially all from seedlings. There were a few
areas that had small sections of robust adult plants and numerous flowering
shoots but these were rare and made up only a small proportion of the total
area in this section. Close examination of transects established at the
Goodwin Island NERRS site has shown extensive seedling abundance in
2006. However, several transects in the York River revealed little
eelgrass in areas that just a few years ago were densely vegetated. Some
of these areas had been influenced by Isabel and had begun recovering when
the 2005 defoliation event knocked them back further.
MOBJACK BAY AND THE AREA ABOVE NEW POINT COMFORT LIGHTHOUSE (CB Segment
(Flight lines 91, 91a, 92, 92a, 93, 94; flown on June 14) (Quads 122, 123,
SAV also completely defoliated and died in most areas in 2005 except for
the regions along the north shore close to the mouth at New Point and a
small region around Horn Harbor just above New Point facing the bay. The
photography and quite a bit of field observations have shown significant
recovery in these regions in 2006. Seedlings have fueled much of that
recovery, but there has been some robust growth in those areas where adult
plants remained in the fall, 2005.
PIANKATANK RIVER and MILFORD HAVEN (CB Segment PIAMH)
(Flight lines 89, 90, 91; flown on June 8) (Quads 117, 118, 123)
Eelgrass in the Piankatank and Milford Haven areas also defoliated and it
appears most died (an interesting observation we made here, but noted
elsewhere, was that where eelgrass and widgeongrass co-occurred, eelgrass
died out while widgeongrass remained, again suggesting this phenomena was
temperature induced). It appeared that eelgrass at the south end of Gwynns
Island (refered to as "the Hole in the Wall") regrew vigorously from some
surviving stock but other areas are only sparsely vegetated in 2006.
LOWER to MIDDLE RAPPAHANNOCK RIVER and CORROTOMAN RIVER (CB Segment RPPMH,
(Flight lines 87a,b,c,d, 88, 147; flown on June 8) (Quads 110, 111, 116,
Almost all of the SAV in this section has been widgeongrass with some
eelgrass observed along the north shore near the mouth at Windmill Pt. In
2006, it appears widgeongrass is doing quite well in these same sections
and while we have no field observations for these areas yet, I would
surmise that very patchy eelgrass beds remain in the lower section at the
mouth, adjacent to Windmill Pt.
WINDMILL POINT (mouth of RAPPAHANNOCK) to SMITH POINT (mouth of POTOMAC)
(CB Segment CB5MH)
(Flight lines 83, 84, 85, 86, 138; flown on July 17) (Quads 106, 112)
SAV beds in this section consist of both eelgrass and widgeongrass. The
photography has shown SAV beds in many of the same areas as in 2005, but
beds in most areas are less dense that what was noted in 2005. In a couple
of areas, some new beds have appeared, e.g. Fleeton Pt. at the mouth of the
Great Wicomico, which is undoubtedly widgeongrass, based on prior years of
CAPE CHARLES up to and including BIG MARSH and CHESCONESSEX CREEK (CB
(Flight lines 104-107; flown June 4, 13) (Quads 108, 113, 114, 119, 124,
133, 134, 142).
Old Plantation Creek to Cape Charles SAV is very patchy, and more so than
in 2005. This area is very exposed and has numerous sand bars with SAV
sandwiched between the bars. Much of the SAV in this area got hammered by
Isabel and has not recovered.
Cherrystone Creek (Cape Charles area) there are some dense beds near the
mouth along the east side (next to the campground) and appears to be
similar to what we observed in 2005. However, the overall abundance is
below what we have mapped in previous years.
Hungars Creek area there is a very dense bed off the mouth of Hungars
Creek (the Vaucluse Shores area). However, many beds in the creek are
absent or very patchy compared to 2005. In the field, we observed that the
Vaucluse Shores bed had large number of flowering shoots with numerous
seeds suggesting significant adult survival in this region.
Nassawadox Creek SAV is significantly reduced or absent from areas mapped
in 2005. There is one area just north of the creek (Silver Beach) that has
some patchy but more continuous SAV.
Occohannock, Craddock, Pungoteague, Onancock, and Chesconessex Creeks and
adjacent Parker and Finney Islands Creek SAV is significantly reduced or
absent from areas mapped in 2005 although some dense beds remain.
Nandua Creek SAV appears much more robust here and is similar to what we
mapped in 2005.
Big Marsh area and Webb and Halfmoon Island and surrounding areas in
Pocomoke Sound SAV is significantly reduced in several of the areas
mapped in 2005 but there are some areas where adult plants survived 2005,
and where seedling growth has been quite robust resulting in some dense
areas e.g., off Halfmoon Island in Pocomoke Sound.
On July 17, 2006, I went out with Mike Naylor from MD DNR and his crew
to look at their eelgrass testplots in the St. Mary's River. We looked
at plots north of Sage Point (just south of the naval base - NESEA), at
Cherryfield Point and on the east side of St. Georges Island, just north
of Evans Restaurant. At each site there were several one meter square
plots in which they had planted vegetative shoots of eelgrass in the
fall. There were also a couple plots at each site in which 50 eelgrass
seeds were scattered in the fall. For the plots with vegetative shoots,
we counted the number of plantings surviving, which was difficult
because of vegetative propagation. For the seed plots, the total number
of shoots was counted.
The eelgrass was much sparser than the plots at Piney Point planted by
the Wilson Bridge Project. On the other hand the blades were largely
free of epiphytes and looked healthy, with signs of propagation. The
plants at Sage Point were relatively small, but denser than the other
two sites. At Cherryfield Point and St. Georges Island, the plots also
had widgeon grass, making the counting difficult. The eelgrass at these
two sites was very tall and had broad leaves (probably competing for
light with the widgeon grass). Again, the eelgrass looked much more
healthy than that at Piney Point. We also surveyed eelgrass from
plantings in the fall of 2004 (from seed bags). This eelgrass was
widely distributed through the fairly dense widgeon grass bed, and again
We also took a look at the eelgrass at Piney Point. As we had observed
the previous Friday, plots at this site had a high shoot densities of
eelgrass, but the blades are heavily epiphytized and are starting to
defoliate. However, when measuring shoot density on the previous Friday,
we did observe that that there are quite a few young shoots that are
largely free of epiphytes.
See an aerial photo of the eelgrass plots at Piney Point that Justin Reel sent me (in the photo
you can see my crew surveying the plots). I will be going out this
coming Thursday to survey the eelgrass plots at Piney Point and in the
St. Mary's River. I will also check to see if the eelgrass has survived
at NESEA. Widgeon grass is doing very well in the St. Mary's River with
lots of flowers and developing seeds. However, there is very little
widgeon grass at Piney Point.
On July 23, 2006 I surveyed the river side of Eastern Neck Narrows, from
the bridge (lat 39-03.28'N/long 076-13.35'W), around the south shore
(Frying Pan Cove), past Boxes Point (lat 39-03.1'/long 076-12.8W) to an
unnamed point (lat 39-02.74'N/long 076-12.62'W), and the north shore of
the narrows from the bridge to Ringgold Point (lat 39-03.6'N/long
076-13.0W). In this area there was some small patches of redhead grass in
Frying Pan Cove (lat 39-02.9'N/long 076-13.1'W) very close to the south
shore. I also observed some floating redhead grass and millfoil. On the
north shore there was redhead grass and some wigeon grass on both sides of
the mouth of Church Creek (lat 39-03.6'N/long 076-13.0'W). The east shore
of Church Creek appeared to have growth from the shore out to about 20
feet. I will survey this creek next. Overall growth appears much less
than last year. Secchi depths were about .35 m and salinity was 7 ppt.
Nancy Rybicki came out with us yesterday to collect sediment samples from
the transplant sites in the lower Potomac/St. Mary's River. We collected
16 sediment samples from the Wilson Bridge planting sites at Piney Point
(shallow & sparse; shallow & dense; deep & sparse; deep & dense) and 4
samples each from the DNR test plot sites at St. Georges Island,
Cherryfield Point and Sage Point. See photos of the grass at
each of the sites.
As reported last week the eelgrass at Piney Point was dense but heavily
epiphytized. Some of the plots had thinned considerably (see slide 4),
and unattached eelgrass leaves were observed scattered along the bottom
suggesting defoliation. Out of 24 marked plots that we are following
only one had no plants. On the other hand, the denser plots had not
diminished in size, and green tissue was observed near the base of the
shoots (see slides 2 and 3). At St. Georges Island and Cherryfield Points
the eelgrass tended to be taller and almost free of epiphytes. In plots
with less widgeon grass, the leaves were much shorter but still relatively
clean (slide 6). The Sage Point site is deeper than the other sites, and
the water more turbid. The eelgrass plots were denser than St. Georges
and Cherryfield Point and the plants shorter and more epiphytized (slides
11, 12, 13, and 14), though not as badly as at Piney Point.
Temperatures and salinities at the four sites are given below:
Piney Point 26.7 C, 11.6 ppt
St. Georges Island 28.6 C, 13.0 ppt
Cherryfield Point 28.8 C, 13.2 ppt
Sage Point 28.9 C, 13.1 ppt
I will be checking on the eelgrass planted by the Alliance for the
Chesapeake Bay at Webster Field later today and will let you know how its
doing on Monday.
On July 30, 2006 Church Creek was surveyed from lat 39-03'-30.3"N/long
076-13'-03.1"W, up the western shore of the creek to a point at lat
39-04'-49.7"N/long 076-13'-10.5"W, and back down the eastern shore of
the creek to a point at lat 39-03'30.3"N/long 076-12'-55.5"W. Along
the western shore there were some small beds of redhead grass just
inside the mouth of the creek, maybe .25 acre in extent. From here,
there was nothing up the west side of the creek until some small
patches of wigeon grass began appearing north of lat 39-04'-29.3"N/long
076-13'-10.8"W. Progressing northward from here to the turnaround
point, more wigeon grass patches appeared, along with several very
small patches of millfoil. Total aerial coverage was very small.
Along the eastern bank of the creek from the turnaround point
proceeding southward there were areas of wigeon grass mixed with
redhead grass, in some areas fairly dense, extending out into the water
50-75 feet from shore, in other areas restricted to 10-15 feet from the
shoreline. There were several small stretches along the eastern shore
with no detectable growth. Best growth along this shore was at a point
of lat 39-03'-41.9"N/long 076-12'-52.4"W, with mostly redhead grass
mixed with small amounts of wigeon grass. At this location secchi
depth was ~.35m and salinity 8 ppt. Along the eastern shore of the
creek there was a transition of mostly wigeon grass (with small patches
of redhead grass) at the upper reaches of the creek to mostly redhead
grass (with patches of wigeon grass) near the mouth of the creek.
Along this shore there may be up to 4-5 acres of total coverage.
Notable was the complete absence of elodea and the near absence of
08/01/06 Bob Orth, VIMS
We have finally been successful in acquiring photography over the mid-bay
island complex area (Tangier to Bloodsworth Islands) and the adjacent
tributaries on the western shore (Little Annemessex River to Fishing
Bay)! There are some interesting observations noted below compared to
2005 but the main points are that it appears there are some very robust
populations of widgeongrass in some of the areas noted below this year,
notably Bloodsworth Island, and that eelgrass populations in the mid-bay
have rebounded and are doing well (so far).
In addition, I took a low level reconnaissance flight over some of
Virginia's freshwater areas which I'll describe at the end but the
freshwater SAV's here are doing quite well.
I want to once again thank Peter Bergstrom and as well as Chris Tanner (St
Mary's River) and Terry Willis (Chester River and Eastern Neck Island) who
have taken the time to write up their SAV observations which we have posted
on our web site
We now have our sights set on the rest of the bay and tributaries and hope
we do not have another rain event like what we had in June that turned the
upper bay brown for weeks. If you have a chance to look at the Modis
satellite images each day, check out how the bay has changed since that
rain event - its pretty neat!
POCOMOKE SOUND (CB Segment POCMH, TANMH)
(Flight lines 109, 110, 111; flown July 24) (Quads 100, 101, 108, 109)
SAV along the north side (MD portion) around Broad Creek and into Broad
Creek going to Crisfield, is present but not as widely distributed as last
year. The beds at the mouth of Broad Creek heading toward Great Fox
Island are very patchy compared to 2005, most likely a reflection of the
eelgrass dieback in 2005.
WATTS ISLAND (CB Segment TANMH)
(Flight line 111; flown July 24) (Quad 107)
SAV is still present on the east side of island but is very patchy, similar
to last year.
GREAT FOX ISLAND (CB Segment TANMH)
(Flight lines 109, 110, 111; flown July 24) (Quad 100) SAV is present
along the east side of the Fox Islands and in the shoal area called Cedar
Straits. While the inshore area is dense (probably widgeongrass) a large
portion of the outer shoal area appears to be much sparser or even absent
in 2006, most likely a reflection of the eelgrass dieback in 2005. Beds in
this area are still quite reduced from what was recorded in the late 1980s
and early 1990s.
TANGIER and SMITH ISLAND (CB Segment TANMH)
(Flight lines 112, 113; flown July 24) (Quads 91, 92, 99, 100, 107). SAV
is dense and abundant in a number of locations, notably Mailboat Harbor
inside Tangier Island, the area around Fishbone Island (just north of
Tangier Island) up to South Point Marsh on Smith Island. Much of this area
is covered by eelgrass in the deeper portions (which has been field
verified by VIMS staff) and widgeongrass in the shallows. The large shallow
water area near Ewell (the Big Thoroughfare) and many of the cut-throughs
to the island have patchy SAV this year. Again, the amount of SAV is still
a far cry from what has been reported in the 1990s.
SOUTHMARSH ISLAND (CB Segment TANMH)
(Flight lines 5, 6, 137; flown July 25) (Quad 91) SAV beds are present in
Sheepshead Harbor, Pry Cove, and Johnson Cove, with general distribution
similar to past years. Some portions of the area are dense.
BLOODSWORTH ISLAND (CB Segment TANMH)
(Flight lines 5, 6, 137; flown July 25) (Quad 83) There appears to be a
significant increase in SAV between Adam and Northeast Island and into
Northeast Cove at south end of Bloodsworth Beds compared to 2005, esp.
between Adam and Northeast Island. The large bed in Okahanikan Cove is
again present and dense. These areas are dominated by widgeongrass, as
several of us noted in ground surveys in 2005. The large bed at the south
end off Adams Island has undergone large fluctuations in the past, typical
of widgeongrass, but interestingly the bed in Okahanikan Cove has persisted
for many years and has not undergone these drastic fluctuations.
HOLLAND ISLAND (CB Segment TANMH)
(Flight lines 5, 6, 137; flown July 25) (Quads 83, 91) Two large and very
dense beds have appeared along the east side of the island in 2006, most
LITTLE ANNEMESSEX RIVER (CB Segment TANMH)
(Flight lines 110, 111; flown July 24) (Quads 100, 101) Many of the dense
beds noted in 2005 are either absent or sparse. There are a couple of
areas that do have dense beds, notably at the mouth along the south shore
off Great Pt.
BIG ANNEMESSEX RIVER (CB Segment BIGMH)
(Flight lines 1, 1A; flown July 24) (Quad 93) SAV is present primarily
in dense beds at or near the mouth, esp. in Hazard Cove on the north side
and adjacent to Jackson Island at the mouth of Jones Creek on the south
shore. Some beds esp. at the north end of Janes State Park are much
reduced from 2005.
DEAL ISLAND AND LOWER MANOKIN RIVER (CB Segment MANMH)
(Flight lines 2, 3, 4; flown July 24) (Quad 84) There is not a lot of SAV
in this system in 2006 and what is present is at the mouth along the south
side. Very little is present around Little Deal Island.
WICOMICO RIVER to FISHING BAY (CB Segments WICMH, NANMH, FSBMH)
(Flight lines 4-11; flown July 24) (Quads 74, 75, 83, 84, 85) There is
essentially no SAV in these sections, as noted in previous years.
LOW LEVEL AERIAL RECONNAISSANCE OF VA FRESHWATER AREAS ON JULY 28 Finally, I took a low level flight (500 ft) on July 29 over some of the
upper portions of the Virginia tributaries to get some insights over how SAV was
doing in these systems, before we get the high altitude photography. I was
impressed by what we saw. We started over the Rt. 3 bridge in the lower
Rappahannock River and proceeded along the north shore over Carters Creek
up to the Corrotoman River. There was an abundance of SAV, which we know
is pretty much widgeongrass. It appeared to be quite robust and thicker
than what we observed last year. We were flying close to low tide and much
of it was laying on the surface suggesting that what we were observing was
an abundance of the flowering shoots. From what we noted in the high
altitude photography highlighted above and these observations, it does
appear that widgeongrass in some areas of the bay is doing very well!
We next proceeded to the upper Piankatank River (Quads 116, 117, 118) where we mapped SAV for the
first time last year. SAV was present again and quite thick. Ken Moore
has been doing some work here recently, and reported finding several
freshwater species, primarily Ceratophyllum, Potamogeten pusillus, and
Elodea. What a contrast from the lower river where eelgrass is present but
not expanding despite a lot of effort on our part to restore it.
We continued over to the Mattaponi (Quads 225, 226) and Pamunkey (Quads
225, 228, 229) rivers and the SAV was really thick. Our field surveys
have shown these areas are now dominated by hydrilla. SAV is continuing to
expand downriver in the Pamunkey and all the little creeks entering these
systems are also loaded with SAV.
We then headed over to the James River and headed down river to the
Chickahominy River (Quads 127, 128, 210). While we noted no SAV in the
mainstem in this section several of the smaller creeks entering the James
appeared to be loaded with SAV, in particular Herring Creek (Quad 125) just
down from Westover Plantation and close to where Ken Moore is involved in
some freshwater restoration. It was pretty impressive given how turbid the
mainstem James appeared!
We wrapped up flying up the Chickahominy River (Quad 127, 128, 136, 210) and found abundant SAV from
about mid-river to the dam. The downriver areas only have sparse SAV and
hugging the shallow areas next to shore. All the smaller creeks entering
the Chickahominy are loaded with SAV. The SAV in this region is dominated
by hydrilla but further downriver, Najas minor and Ceratophyllum are dominant.
Please share this with any other interested individuals or groups.
I wanted to pass along a quick note to let you know what I've been seeing
at some of the areas throughout the Bay
At Monie Bay, near Fishing Bay where you've flown, we've seen a fair
amount of fringing SAV beds in the tributaries (Big Monie Creek, Little
Monie and Little creek) around Monie Bay. We've seen quite a bit of
Ruppiamaritima (Rm), Zannichelliapalustris (Zp) and Potamogeton pusillus (Ppu) particularly in Big Monie
Creek. Greater distribution then even last year. I can get you GPS
coordinates if you like but I don't think these areas show up on your
aerials as they are fringing beds in relatively narrow creeks.
Also, I was out with Todd Beser at US AEC last week in the lower Gunpowder
(Dundee and Saltpeter creeks and around Carroll Island) and there is a
tremendous amount of Vallisneria americana (Va) and Potamogeton perfoliatus (Ppf) in those
creeks and lower Gunpowder just north of Battery Point. Va and Ppf are
the dominant plants in the lower Gunpowder/Carroll Island/Dundee and
Saltpeter creeks areas, mixed with Myriophyllum spicatum (Ms), Ceratophyllum demersum (Cd), and
Ppu. We also saw some healthy crispus beds that is fairly unusual to
see this late in the summer. The visibility was marginal compared to
previous "good" SAV years (1996-2001) and I suspect this is somewhat due
to the recent rains but more likely due to the lack of ground cover
(typically Najas guadalupensis (Nju) and Elodea nutallii/canadensis (Ec)) that was
common during these years. There was some Nju in Benjies Cove
and up in Dundee Creek but not much in Battery Cove where it used to be
the dominant species. Additionally, elodea used to dominate Benjies Cove
and was common in Dundee Creek and there were only very trace amounts observed
throughout the area. I'm not sure why the shift or loss of the ground
cover species as we used to see Va, Ppf, and other species
co-existing well with elodea and najas.
We also have not seen the Hydrilla verticillata (Hv) back in Otter Point Creek and many of
the other areas (Church Creek and lower Bush River) as we had in 2003 and
2004. Again, not sure why the change but where Hv once dominated
Otter Point Creek, almost forming an impassable meadow of grass, we are
only seeing trace amounts of Hv in Otter Point Creek and very little
to no Ms, Va, Cd and other species that we
observed last in any considerable amounts in 2004. The Hv began to
disappear in 2005 and has not really returned in any significant amount in
2006. Again, not sure why the shift and/or loss. It first came in in
2002, boomed in 2003 and 2004 and then has pretty quickly disappeared in
2005 and 2006.
There are definately some interesting changes in SAV distribution and
composition occurring in the Bush and Gunpowder Rivers. It would certainly
be interesting to know why and I'm curious to see what you all see in the
imagery for this area.
This past Friday I had the opportunity to spend the day boating on the Susquehanna Flats with Capt. Mike Benjamin. Mike has been boating, fishing and hunting on the Flats since he was a child, and he is on the water more days than not. The Flats are notoriously difficult to navigate, and many a boater has spent long hours waiting for a rising tide to carry them off a sandbar. Having a guide like Mike with detailed local knowledge is a huge advantage- I was able to get to places I would never have tried to navigate on my own.
We started the day in the Northeast River, poking into coves from the town of Northeast all the way out to the mouth. SAV in the Northeast River has been increasing every year, but above Charlestown there is still almost nothing. Immediately below Charlestown, however, there is vegetation on both sides of the river in every cove. The beds are milfoil on the deeper end, then mostly hydrilla and wild celery in the shallows. Water stargrass is in a few spots, but does not co-dominate biomass as it does on the Flats proper. SAV in the Northeast is growing at depths of 4 feet and below, considerably less than in the Flats.
Leaving the Northeast River, we headed east and then followed the broad, shallow channel south around the very dense, shallow SAV bed that dominates the north side of the flats. This shallow bed (south-east of Stump Point), which a few years ago was so dense it looked like an island, has been much reduced in density. This reduction was noticed after hurricane Ivan, and reports are that Ivan left up to a foot of sediment in this area and in some spots along the channel to the east. This shallow bar is covered by unconsolidated sand, and it shifts unpredictably when Susquehanna River flows are very high. No one who knows the area ever attempts to take a boat through this spot, as grounding would be a certainty. We skirted around it, keeping it a few hundred feet to our west, and we could see a lot of wild celery and water stargrass fragments being washed out. So although this bed is not as dense as it once was, and is apparently even more shallow, it still has a lot of SAV visible and appears to have the same mix of species we found everywhere else.
Once we were south of the shallowest spot, we moved back east so we could cross the Flats from the east to the west near the widest point, a distance of about 7 miles. The type and density of vegetation changes many times as one moves across the gigantic Flats bed. Against the eastern shore, halfway between White Point and Rocky Point, a dense bed of wild celery, water stargrass and milfoil extends several hundred yards from shore where two years ago there was only sparse milfoil. From the deepwater edge of this SAV bed up to shore the water is fairly clear, with the bottom visible at 3'. As you move west and the water depth increases to below 6' (mlw), the grass disappears and the water becomes more and more turbid, with a Secchi depth of 18'' to 2'. At a distance of 1.05 miles from the eastern shore (N 39 30.123' W 76 00.537'), as the depth changes from 6' to 5', the first clumps of milfoil begin to appear- becoming more and more dense. As the depth drops from 5' to 4', clumps of wild celery and water stargrass appear, growing more and more dense until they form a solid mass of 75-100% cover that continues for several miles. Inside this dense central bed, the water is very clear. Secchi depths range from 4-5', and the bottom is visible everywhere except in the many ditches that cross the Flats.
In some locations, particularly in areas far from the ditches where water movement is minimal, dark filamentous algae covers everything. These patches of algae are quite large in some spots, covering several acres so densely that no SAV is visible. I imagine that if color photographs of the Flats were taken right now, these algae-covered patches would stand out quite distinctly from the lighter colors of the SAV. We have seen this on the Flats before, and it seems to appear and disappear fairly randomly and to not cause great damage except in localized areas. While numerous patches of algae were scattered through the Flats, each patch was surrounded by healthy SAV. With miles of good SAV, it is difficult to be too concerned (although we certainly want to keep our eyes on it).
Great beds of SAV absolutely covered the main Flats bed, with wild celery, water stargrass, and milfoil being by far the dominant species. We also observed coontail, spiny naiad, slender pondweed, and hydrilla in the area, but at much lower densities. We doubled back as we approached the deep water shipping channel on the west side of the Flats, and headed south towards Turkey Point. The southern side of the Flats bed was very similar to the central part of the bed except that plant density is reduced and the water is far more turbid. This turbidity seems to always be present on the south side of the Flats, even when the middle Flats have more than 10' of visibility as we saw last summer. Starting at Turkey Point and moving north, the vegetation along the eastern shore seemed to be more or less continuous all the way up to White Point and into the Northeast River.
From White Point, we went around Carpenter Point to look at Furnace Bay. Looking in from Stump Point, Furnace Bay appeared to be 100% vegetated with hydrilla- with vegetation visible on the surface despite being several hours away from low tide. Vegetation was visible far back in Mill Creek and as far as we could see into Furnace Bay itself. Approaching the bed, far from shore, milfoil clumps were scattered throughout the 5' depth. As the boat came into the bed, we saw that near the mouth there was actually very little hydrilla. The bed was mostly wild celery and water stargrass, with some coontail, spiny naiad, and hydrilla in patches. It was incredibly dense, and bare sediment could be seen in very few spots. The water inside this bed was extremely clear. As we penetrated deeper into the bed, far back into Mill Creek, hydrilla became the dominant species- forming a thick mat that reached to within a foot of the surface. We moved slowly through the grass beds all around this area, watching feeding waterfowl, massive schools of minnows, big largemouth bass, and all the things one grows accustomed to seeing in SAV beds. It was a great way to end the day.
In summary, I think that the Flats SAV beds didn't suffer greatly from the rainfall events of late June and early July of this year. With the exception of the loss of density in the northernmost portion of the bed, every location I visited looked as good or better than in 2005. Capt. Mike reported that the water has been clearing slowly but steadily ever since the storm, and he predicted that in a week or so the water would be extremely clear- similar to last year (unless we get another big storm). Developmentally, the water stargrass has begun to flower in many areas, and we even saw a few wild celery flowers reaching the surface. I took a few pictures, but of course you can't really detail the changes I'm talking about with a camera, so they are not very exciting if you have ever seen SAV before...
I looked for SAV in the upper Magothy via kayak on Tues 8-8-06, with John
Kuriawa and Sophia Kim. We looked during a falling tide to allow us to
get farther up the upper tidal reaches of Old Man Creek and the upper
Magothy. We found the following (see map).
* no dark false mussels seen except in one creek
* less or none of the SAV species usually found in lower salinity
years, except wild celery is doing well
* more of the SAV species that usually does well in higher salinities
(sago pondweed or Ppc)
* some of the redhead grass beds upriver of Henderson Point that
appeared and then died back in 2005 are back in 2006 and may persist
with enough density to be mapped in the 2006 aerial survey
* redhead grass with widgeongrass on South Ferry Point and in Swan Cove
are doing well with some increases in density and extent since last
* wild celery planted in late June was doing well; redhead grass
planted nearby in 2002-2003 appears to be gone, after doing well for
1-2 years, but there are redhead plants nearby that probably started
from seeds produced by those beds
1. No dark false mussels (DFM) were seen (except I have seen them earlier
this summer at low tide on pilings in Old Man Creek, where I keep my
kayaks). Last summer I found DFM as far upriver as Beachwood Forest,
upriver of Riverdale, and in 2004 I found them almost to the upper tidal
limit of the Magothy on a floating pier.
2. Upper Old Man Creek and the upper Magothy had less SAV than in past
years, probably due to higher salinity this year. There were much
smaller patches of Callitriche (Cl) in Old Man Creek this year compared
to recent years, and less sago pondweed (Ppc) there as well. The upper
Magothy had almost no SAV, one shoot of Ludwigia, compared to large,
dense beds of Callitriche, Potamogeton epihydrus (Pe), and some Ludwigia
at the same spot in 2004; I did not check it in 2005. All of these
(except Ppc) are freshwater species that usually are only seen in tidal
waters during high flow/low salinity years, so I did not expect to see
many of them after the low flow this spring.
3. The Magothy mainstem between Riverdale and Steedmans Point (just
upriver of Swan Cove) had much less SAV than I found there last July.
This year we found only a few shoots of milfoil (Ms) and one of slender
pondweed (Ppu), with a few small, sparse patches of redhead grass (Ppf)
between Old Man Creek and Steedmans Point, while on 7/12/05 we found a
few small (6-8' across) but dense patches of redhead grass in the
shallows upriver of Old Man Creek, and some widgeongrass (Rm), and
several patches of redhead grass between Old Man and Cockey creeks.
These patches were all gone later in the summer, on 8/26/05. See the map
attached to last year's report on 9/14/05 for comparison
(http://www.vims.edu/bio/sav/2005obs.html#noaa091405). We did not find
any of the Elodea (Ec) that we found in one cove in this reach last year,
as expected due to the high salinity this spring.
4. Now the good news starts! The wild celery (Va) that we planted at the
Grachur Club on 6/29/06 (just downriver of Cockey Creek) was doing well
with about 50% of the exclosure covered by healthy shoots, about the same
or a bit more than what was there when we planted. Salinity was 5 ppt, a
good range for this species. A few shoots had been uprooted, possibly by
rays, and we replanted them.
5. There was no trace of the redhead grass we planted a bit farther
downriver in 2002-2003, but the new beds of redhead we found nearby last
year were still present this year (100 and 101 on the map), so I
think the seeds from the beds we planted spread to these nearby areas.
It may be that newly planted redhead beds only have enough stored energy
to survive for 1-2 years (about how long the original 2002-03 beds
lasted) unless the water clarity, sediments, wave energy, and other
conditions are adequate to allow them to store more energy. In other
words, there appears to be an intermediate range of conditions that are
adequate to allow short-term, but not long-term survival of planted SAV
beds, where long-term (at least for redhead grass) means 3 years or more
from the planting date.
6. More good news: the cove just upriver of Henderson Point on the south
shore had much denser and larger SAV beds than last year, mostly Ppf with
some Rm and a few shoots of Ppu. Last year this bed was sparser and died
back before the aerial photos were taken in September, so none of it was
mapped except a small bed right at Henderson Point, labeled D1
(http://www.vims.edu/bio/sav/sav05/quads/rb023d.html). This year I'm
hopeful the beds in this cove will last long enough to show up in the
aerial survey. I don't think any SAV has been mapped in this cove since
1978 (see 1978 map with the beds in this cove circled).
7. We found no SAV on the shore just south of Henderson Point, where a
sparse bed was mapped last year (E1) and we found sparse Ppf and Rm in
early September 2005.
8. We found very dense beds of Ppf and Rm with some Ppc and Va growing to
the surface on South Ferry Point, extending out to water at least 1.5 m
deep at low tide. See photo showing
flat water over the tall beds and rough water outside them. These beds
seemed much more consistently dense than they were last September,
although they were classified as density 4 last year, and included some
of the densest redhead grass beds I have ever seen on the Magothy
(rivaling the density found in the bed outside Asquith Creek on the
Severn). At one spot the beds were so dense that my kayak stopped after
I had drifted under a pier. There appeared to be more sago pondweed than
last year, as expected due to the higher salinity this spring. As usual,
we found wild celery towards the eastern side of the point, and even
though we had a drought this spring, the plants were robust (see photo). Usually the Va at South Ferry Pt. is present
but stunted and tinged with brown in years with high salinity such as
2002 (when salinity nearby was 11 ppt), although salinity here on 8/8 was
5 ppt, an excellent range for wild celery. Steve Ailstock found wild
celery near this same spot in the mid to late 1980's so the beds appear
to have persisted here for at least 20 years.
9. We found the density and extent of redhead grass were about the same
as last year at North Ferry Pt. and in the eastern end of Swan Cove, where
a dense bed was mapped last year (EA4). We found one clump of wild
celery (Va) here; I also found a clump in this cove in 2002
(http://www.vims.edu/bio/sav/sav02/quads/rb023_page.html). We did not
have time to ground truth the rest of Swan Cove, but I'll try to get to
it in a few weeks.
On August 14 Hail Creek on Eastern Neck was surveyed from Cedar point
at lat 39-00'-33.2"N/long 076-12'-35.8"W going up the left side of
the creek, around the head, and down the opposite shore to a point of
lat 39-01'-08.3"N/long 076-12'-26.4"W. While there was SAV present,
it was mostly confined to two small areas. One was just inside the
entrance of the creek at lat 39-00'-40.5"N/long 076-12'-40.1"W, where
there was a mixture of redhead grass with small amounts of wigeon
grass. The second area was at the head of the creek at lat
39-01'-20.7"N/long 076-12'-31.5"W, where there were patches of wigeon
grass. In both areas the grass was hugging the shoreline. Aerial
extent in both cases appeared to be in the 1-2 acre range. This is
much less than was found in the same area in 2005. Secchi depths were
less than ~ .3 m and salinity was 9.5 ppt.
On 8/17/06 I kayaked about 8 miles along the north shore of the lower
Magothy, from Dobbins & Little Islands upriver to the start of Magothy
Narrows. I used a sit-on-top kayak that we carried to the area on the
stern of the 27-foot Boston Whaler In Situ that we use to do benthic
mapping in shallow waters; this worked well. I found SAV growing out to
about 1 m deep, which agreed pretty well with the depth at which the side
scan sonar on the In Situ showed SAV beds.
In general there seemed to be a bit less SAV than what was mapped in this
area than last year, and probably less widgeongrass. The map shows a few specific areas circled in blue, that had mapped beds in 2005
but no SAV that I could find on 8/17. Two of these were just outside
Grays Creek, and two were covers along the shore of Hunters Harbor. One
of the 3 coves along that shore still had dense SAV, as it did last year,
mixed Ec (Elodea) and Ms (milfoil). It is very shallow and has not been
dredged for boat access. The other 2 coves which lacked SAV this year
are deeper because they were dredged for boat access. Perhaps their
greater depth allowed more of higher salinity water to enter during the
spring drought, which would tend to cause Elodea and milfoil to die back.
The species I found were Ppf (redhead grass), Ec (Elodea, probably E.
nuttallii), Ms (milfoil), Ppc (sago pondweed), Rm (widgeongrass) and one
site with Ppu (slender pondweed). As usual, the only area I visited that
had all of these species in the same place was lower Cornfield Creek.
Most of the other beds were a mixture of Ppf and Rm. Ppf seemed to
predominate in most of them, while in the past, some of the beds in this
area were mostly Rm. In wet years in the Magothy we tend to see more Ec,
and in dry years more Ppc, but this year I found moderate amounts of both
species. The rainfall this year has been so variable, it will be hard to
classify this as a wet or dry year. I did not find any of another lower
salinity species, wild celery (Va), which I have found both in Cornfield
Creek and Magothy Narrows in the past, but its beds are small and easy to
miss. I found it this year on 8/8 at South Ferry Point and in Swan Cove
where it was doing well.
On 8/18/06 I kayaked the lower portion of Weems Creek, launching at
Tucker St. My main goal was to check a small redhead grass planting
that Corinne Irwin and I organized, with help from John Rodenhausen at
CBF, near the mouth of the creek in June 2003. See map for my route.
I was pleased to find that the rectangle that we planted in 2003 still
had about 25% cover of short Ppf, visible only with a view scope. There
had been a little spread outside the exclosure, but it's hard to tell if
the redhead was from what we planted, since there are redhead beds on the
mainstem of the Severn outside the creek. Three years is the longest
survival I've had to date of small redhead planting projects that I
supervised; the redhead we planted on the Magothy in 2002 tied this
record, surviving until last year (2005) but gone this year.
Weems Creek has never had any beds mapped inside the creek to my
knowledge, and the SAV in the lower creek remains sparse, short and
shallow this year. Some of the lower portions of this creek have a steep
bottom slope that precludes much SAV growth unless the water were much
clearer. I was surprised & pleased to find dense and bright green Elodea
(Ec) in one cove, at Waypoint 195 (see photo). I found it only
by raking next to the other SAV (Ms) because it was prostrate, just as Ec
often is in the Magothy. Like the slender pondweed (Ppu) that I found in
Saltworks Creek on 6/22/06, this appears to be the first record of Elodea
in the Severn. At Waypoint 196 I found a curved breakwater on a point
that looked like it may have been built to encourage SAV growth (see
photo), but I could find no SAV in it, although the depths and
sediments appeared to be suitable for SAV. A citizen reported Ppf, Ms,
Rm, and Zp in the same area as my waypoints 194-197 in 2002 on Quad 30.
I am a resident of McDaniel MD, living in the community of Mallard Point which is located on the northeast branch of Harris Creek. This spring and summer I have spent a lot of time observing the SAV growing in Harris Creek. I have lived in this area since 1983 and can not remember the grass being as plentiful as I have seen this year. However the extreme heat that occurred in July has killed off almost all the grass, the only beds I could find as of 8-18-2006 were located across from Sherwood, MD map 036. I don't know when the aerial photos are taken of this area but if it is after the end of July you will have missed the grass which was so plentiful this past spring and early summer. One additional item - the SAV growing at the old ferry dock located in the town of Claiborne, MD and one large SAV bed growing near the town of Whitman, MD on the bay side seem to have survived this heat.
I am sad to report that the SAV in Broad Creek off the Choptank River is
greatly reduced from previous years. Most of the Ruppia maritima is gone from
our two sampling areas. However, we have observed large beds of
Stuckenia pectinata at the mouth of Broad Creek and Ruppia maritima along the
north bank of the Choptank between Broad Creek and Irish Creek. It
seems that at least in parts of the Choptank River that the summer rains
have affected the SAV beds, contrary to the article in the Easton paper
where Mike Naylor reported the wonderful beds in the upper Bay. A quick
look at the chlorophyll levels etc. in the Choptank
(www.eyesonthebay.net) indicated large algal blooms in various areas of
the Choptank. Perhaps there are different conditions here which have
lead to the reduction of SAV in this area?
It is reassuring that at least in some areas, the grasses are doing well.
On Wednesday 8/16/06, I chartered a small plane to fly the upper bay
from the Choptank River to the Susquehanna Flats to look for any SAV
impacts from the heavy rains in late June. The upper bay was turbid for
nearly a month so this trip was scheduled to occur once satellite photos
identified clear water in the upper bay.
Mark Trice brought his laptop with a GPS and the DATAFLOW
tracking/logging software to help navigate and take pictures. Prior to
flight he loaded the 2005 SAV aerial survey data allowing us to see our
position in relation to the 2005 SAV bed locations.
You can view the story: Investigations of Impacts to SAV from June 2006
http://mddnr.chesapeakebay.net/eyesonthebay/August2006_overflight.html, which contains detailed SAV bed conditions, selected photographs taken
during our trip with the flight path and ground observations of the
Flats from Mike Naylor, on our Eyes on the Bay Monitoring Stories
I took prints of the 8-5-06 aerial photos that I got from Bob and checked
some spots that looked like they might have SAV on the lower Magothy last
Thursday, 8/24/06. I went in the boat of local volunteer Dave Lines, who
was taking notes of fishing and crabbing spots he might try later.
North shore (see map)
Some spots where little grass was visible in the aerial photos had Ppf
almost all the way around (Park Creek), while Broad Creek had only one
tiny patch of Ppf with a bit of Rm (wpt 209), even though I thought I saw
likely dark patches elsewhere in the creek. We checked the upper end
of "North" Grays Creek (it's actually the eastern arm, but the bog
upstream of it is called North Grays Bog), and found that the SAV I saw
at the Sylvan View marina last year was considerably reduced this year
(wpt 219) compared to 2004. We found sparse short & shallow Ppf and Ms
this year, whereas on 7/10/04 there were dense beds of Ppu (slender
pondweed) in the marina, with Rm & Ms (see
http://www.vims.edu/bio/sav/sav04/quads/gi024_page.html). This year we
found dense beds just upstream of the marina (wpts 220 & 221) with Ppf,
Ppu and Ms, which I did not check in 2004 because I did not have a boat.
These beds had some of the densest beds of Ppu that I've seen; one
wonders if Ppu shoots came to the marina on a boat that had traveled up
the Bay to where Ppu is more common, and then spread up the creek from
there. The beds up from the marina were not there in 2004 but were
present in 2005 (http://www.vims.edu/bio/sav/sav05/quads/gi024d.html, bed
KB2), based on the aerial survey. We did not have time to check the
"south" arm of Grays Creek, which also appeared to have SAV in the 2006
South shore (see map)
Working east along the south shore, the extensive shoal off Ulmstead
Point had some sparse beds of Ppc with a bit of Rm and Ppf (wpts 210 &
211), as it usually does in years with higher salinity. Scheide's Cove,
which has an amazingly narrow but deep entrance, had a few small and
shallow beds of Ppc, Ppf and Rm off two marshes (wpts 212 & 213). The
surprisingly indistinct SAV signatures in the Stonington bed on the south
shore (wpt 215) were apparently because the SAV was shorter, and the bed
narrower, than it was in past years. A new pier was being built right
through the SAV bed--I wonder how it got permits! (see detail of
aerial photo, and photo of pier construction) Lake Placid had no SAV; I
've only found grasses in there a few times since 1995. The much darker
signatures in the aerial photo at the mouth of Deep Creek turned out to
be much denser and taller beds of mostly Ppf (wpts 216 & 217), compared
to the beds off Stonington. It was the only time that day that the prop
on our boat got clogged with SAV.
Upper Magothy/Cockey Creek (see map)
The small beds of Ppf that we found between Old Man and Cockey creeks on
8-8-06 has mostly died back. All I could find where there had been a
moderately healthy Ppf bed on 8-8 was a few very sickly strands of Ppf
that had almost no leaves left (222). At a spot where we found a few
shoots of Ms on 8/8, I could only find one sickly shoot of slender
pondweed (Ppu). The wild celery (Va) that we planted at the mouth of
Cockey Creek in late June was still present and green, but it was a bit more
sparse than it was on 8/8. A kayak survey of all of Cockey Creek found
no SAV at all, including spots that had fairly dense beds of Ppf last
year (see map for their former extent up the creek). A small bed of Ppf
that I found downriver from Old Man Creek on 9/1/05 also seemed to be
gone this year (see map).
Went out to Webster Field to check the SAV beds that stood out in the
aerial photo. I've marked the areas checked on slide 2 of the PPT
presentation. In both areas all I found was widgeon grass. The
vegetative shoots lacked the bayonet found in sago and there were some
typical Ruppia male flowers.
Slide 1 is of eelgrass in the WWB plots at Piney Point. Most of the
plots have defoliated, but some still have short, healthy shoots. As
the water temperatures are cooling down, I think some of these will
A group from the Chester River Association looked for SAV in the
Corsica on Friday, 9/8/06. They reportedly searched the north shore
from Green Point (N 39º04.150'/W 76º05.150') to a point they term the
"mouth" of the river (N 39º04.956'/W 76º07.733') and found no SAV
present. They particularly searched the areas where SAV was present
On September 17 the mouth of the Corsica (north side) was surveyed from
a point on the Chester at lat n39-05'-51.4"/long w076-08'-17.9" to a
point on the Corsica at lat N 39-05'-02.4"/long W076-08'-01.7". No SAV
was seen, either attached to the bottom, floating on the surface, or
washed up on what shore there is here. None could be raked up. The
bottom here is very hard, and inside the mouth of the Corsica there is
extensive rip rap extending out from the shore line with partially
submerged groins that are perpendicular to the shore line. Water
clarity by secchi disk was in the 1-1.1 m range in many places along
the track. The track was done at two distances from shore over much of
the range-at a depth of 3-4 feet (20-30 feet off the shore line) and at
a line about 50' outside of that over much of the range.
On Sept. 25, 2006 with an assist from the Chester River Keeper the following areas were surveyed:
Robin Cove lat N39-04'26.9"/long W076-09'03.3" to lat N39-04'13.5"/long W076-08'48.2"
This cove is covered between the above points with eurasian millfoil that extends out from the north shore from the western most surveyed point to an extent of 50-75 feet, then quickly expands to cover the entire breadth of the cove (northern shore to southern shore) to the easternmost surveyed point. Mixed in with the millfoil are small pockets of redhead grass near the center of the track along with some very small amounts of elodea. Near the head of the cove (the easternmost point above) there is approximately a 60/40% mixture of millfoil/wigeon grass. Secchi depths in the cove were ~ 1.25 m or more. There is the remnant of a flow control structure across the mouth of this cove that limits wave action from the Chester River, and there is a similar remnant about 3/4 of the distance into the cove. Estimated total coverage 4-6 acres.
Grove Creek and Reed Creek The upper region of Gove Creek was surveyed around a point at lat N39-03'18.2"/long W076-08'58.5"and no SAV was found, either in the water, floating or on the beaches. No SAV was found on the way in to this point. Reed Creek was surveyed around a point at lat N39-02'52.7"/long 076-09'42.8". No SAV was seen, either in the water, floating or on the beaches. No SAV was seen on the way in to this point. Secchi depth ~ .6 m.
Local volunteer Pete Worch and I checked SAV on Breton and St. Clements
Bays in his boat on 9-27-06. Salinity was 13 ppt and Secchi depth was
1.1 meters at his dock, where we also planted SAV in 2002 (see map). Pete's boat could not get into the shallows so I
jumped in and waded the shallows where I thought there would be SAV.
In general we found less SAV than was mapped there last year. We only
found short form widgeon grass (Rm), and it was pretty patchy in most of
the places where I found it. It was clearly visible from the surface in
most locations, except where wind and waves had stirred up the bottom and
made the water too cloudy. Most of the plants extended only to water
0.6-0.7 m deep at low tide, and none had flowers or seeds.
A resident living near waypoint 238 on the W side of lower St. Clements
Bay told me that the grasses at that spot were much thicker last
year--thick enough to be hard to walk through. That bed had 28 mute
swans feeding on it when we approached.
Based on Bob Lewis' observation from June 2006, some of the widgeon
grass beds in Breton Bay were also much denser earlier this year. The
spot where he found "choking widgeon" in June 2006 (the 2004 planting
site) had only sparse patches of short form Rm on 9/27.
We found no SAV at the sites where we planted redhead grass in 2002, 2003
and 2004. However, some of the 2004 plants had been there earlier this
summer. Bob Lewis checked the McAllister planting done in 2004 last year
and earlier this year, and wrote: "I found Redhead grass there last June
2006 - but only a few sprigs amongst a choking amount of Widgeon. The
fall before , I found a good deal of Redhead and it had spread to a
new one-meter patch some distance away."
The map shows where we found short form Rm (numbered waypoints),
and the 3 past planting sites that we checked and found no plants.
10/09/06 Bob Orth, VIMS
The 2006 SAV season is winding down, but from what we at VIMS and a few
others around the bay have been observing it appears to be shaping up as
quite an interesting year based on both field and aerial observations. A
number of meteorological events in 2006 appeared to have had some effect on
SAV populations: a very dry spring driving salinities way up, the 'big'
June rain event, a very hot July, and then the surprise visit of Ernesto.
Here is what has been happening since my last update in
July. Please note that there have been quite a few, very detailed field
observations reported to us at VIMS and these have been posted on our web
site: http://www.vims.edu/bio/sav/2006obs.html. Once again, thanks to
Peter Bergstrom, Terry Willis, Mike Naylor and other DNR staff, and staff
from Hart-Miller Island for some very detailed field observations over the
last few months!
This report covers photography from the Virginia tributaries (James,
Pamunkey, Mattaponi, Piankatank), most (but not all) of the Potomac River,
Patuxent, West, Rhode, South, Severn Magothy, Patapsco, Back and Middle
rivers, Little Choptank and Choptank rivers, Eastern Bay, Chester River,
Elk, Bohemia, Sassafras and Susquehanna rivers, and the upper 2/3 of the
main Susquehanna Flats.
Here is a brief summary of what we have observed:
1. SAV was abundant in the VA tribs, but there is essentially no SAV
in the mainstem of the James. SAV beds are now dominated by hydrilla in
these other systems. The big question is will hydrilla find it's way into
the upper James (I think it will it's just a matter of time!)
2. SAV appears to be doing quite well in some areas of the
Potomac, notably the St. Mary's River, Breton and St Clements Bay, Nanjemoy
Creek, Aquia Creek (this river had SAV everywhere!) and the mainstem
sections of the region just above and across from Aquia Creek. However,
there is almost no SAV in the VA section from the 301 bridge south to the
mouth and it appears that some of the SAV in the areas of Cobb Island and
adjoining reaches are either gone or reduced from last year (salinity
3. SAV appeared to be doing well in the upper Patuxent, Severn, and
Magothy rivers, but little or none was noted in the South and Patapsco
rivers (many of the dense beds noted in the Patapsco in 2005 were gone).
4. Very little SAV was noted in the Little Choptank River, but SAV has
rebounded in the Brannock Bay area this year.
5. Almost no SAV was noted in the northern creeks of the Choptank
(Harris, Broad and Tred Avon), which appeared to have died out in this
year's July heat. But surprisingly, robust populations of SAV were noted
on the south shore in Cook Point Cove and at the mouth of Chapel Creek, so go
figure this one! (remember we are dealing with widgeongrass)
6. Very little SAV was noted in the Eastern Bay area except for Crab
Alley Bay and Marshy Creek.
7. Recovering SAV populations in the Chester River, especially around
Eastern Neck Island noted in 2005 are pretty much gone (we had suggested
this may happen based on the spring salinity levels).
8. SAV in the Elk River looked fantastic!
9. While SAV was abundant in both the Bohemia and Sassafras rivers,
there has been some reduction from 2005 levels.
10. SAV along the flanks of the Susquehanna River from the dam to Havre
de Grace looked really good.
11. SAV was very thick in Furnace Bay (always seems to be a hot spot
12. And lastly, SAV in the northern part of the Flats appeared dense
and similar to what we had seen in 2005. This was an area we were all
watching very closely following the big rain event in June and it appears
SAV here has managed to persist. It's possible that the fact SAV was
already quite robust when those rains hit that could have made a big
JAMES RIVER MAINSTEM (CB Segments JMSTF, APPTF, CHKOH)
(Flight lines 154A, B, 158A, B, 159A, B, 164; flown Sept. 26; Quads 125, 126, 135, 136, 204 and 207) -
SAV is absent along the mainstem James from below the mouth of the Chickahominy River to Richmond. However, we have again noted SAV in several creeks but primarily further upstream in each of these small creeks, e.g. Grays Creek, Herring Creek, Powell Creek, Upper Chippokes Creek, Wards Creek. We have not made any field observations in these creeks but most likely the species are coontail and najaids.
CHICKAHOMINY RIVER (CB Segment CHKOH)
(Flight lines 155 and 165; flown Sept. 26; Quads 127, 128, 210) -
The Chickahominy River continues to hold most of the SAV in this region of the Bay. Most beds are now dominated by hydrilla, although field observations by VIMS staff have reported both Najaids and coontail in some places.
PAMUNKEY RIVER (CB Segments PMKOH, PMKTF)
(Flight lines 151 and 152; flown Sept. 26; Quads 228 and 229) -
SAV is present and very dense from a mile or so below the Pamunkey Indian Reservation to just above Montague Landing. There is very little shoal area along the mainstem, so much of the SAV is restricted to a very narrow fringe along the river. It is abundant in the many small marsh creeks entering the system in this region. A field check by VIMS staff found predominantly hydrilla in this region. SAV has increased in the downriver section around Big Creek where there is a much broader shoal area and has been generally increasing in the lower areas of this section of the river. Field observations by VIMS staff have reported most beds being dominated by hydrilla but have also found coontail.
MATTAPONI RIVER (CB Segments MPNOH, MPNTF)
(Flight lines 148 and 149, flown Sept. 26) (Quads 225, 226) - SAV beds are dense primarily in the stretch along the Whitehall area (similar to previous years) and are nestled within and between much of the emergent vegetation. Field observations by VIMS staff have reported most beds being dominated by hydrilla but have also found coontail, wild celery, and elodea
UPPER PIANKATANK RIVER (CB Segment PIAMH)
(Flight line 90A: flown Aug. 14; Quad 116) -
SAV has appeared in the upper tidal low salinity areas in the last few years and these beds are quite dense. The total area is not large but their presence is certainly notable. Field observations by VIMS staff have found coontail, and najaid species.
POTOMAC RIVER - ST. MARYS RIVER AND ST. GEORGE CREEK (CB Segment POTMH)
(Flight lines 68, 69; flown Aug. 22; Quads 080, 089) - SAV abundance continues to be very impressive! SAV, which is predominantly widgeongrass, is doing extremely well in this river in all locations reported in past surveys, from Chicken Cock Creek on the eastern shore, and the tip of St. Georges Island on the western side. Distribution and abundance appears to be similar to 2005.
POTOMAC RIVER - HERRING CREEK (CB Segment POTMH)
(Flight lines 68; flown Aug. 22; Quad 079) - SAV beds are absent here this year.
POTOMAC RIVER - SOUTH OF BRETON BAY ON THE MAINSTEM POTOMAC RIVER (CB Segment POTMH)
(Flight lines 68, 71; flown Aug. 21, 22) (Quad 078) - There continues to be an impressive amount of SAV just south of Breton Bay along the mainstem for almost two miles down to White Point Beach. The distribution of this bed is similar to last year and is undoubtedly widgeongrass.
POTOMAC RIVER - BRETON BAY (CB Segment POTMH)
(Flight lines 68, 70; flown Aug. 21, 22; Quads 069, 078) - moderately patchy to dense SAV beds are present this year and appear to be similar to what was observed in 2005. SAV has been persistent in this system over the last few years and is dominated by widgeongrass. Peter Bergstrom has just visited this area and has posted his observations on our site. He noted that much of the widgeon was the short form (non-reproductive), which explains the type of signature we see on the photography.
POTOMAC RIVER - ST. CLEMENT BAY (CB Segment POTMH)
(Flight lines 68, 72; flown Aug. 21, 22; Quads 069, 078) - SAV abundance is very impressive here this year again. There are very dense beds along both shores from the mouth to Cedar Point on the north shore to Tenneson Creek on the south shore. The beds are dominated by widgeongrass (as noted by Peter Bergstom).
POTOMAC RIVER - WICOMICO RIVER (CB Segment POTMH)
(Flight lines 72, 73, 74, 74A; flown Aug. 23; Quads 058, 067, 068, 162) - SAV is dense and more abundant at the head of the river in and adjacent to Allens Fresh Run. SAV beds are present in other sections of the river, but for the most part, much of the river remains unvegetated.
POTOMAC RIVER - COBB ISLAND AREA (CB Segment POTMH)
(Flight lines 72, 73, flown Sept. 2; Quads 067, 068) - SAV is almost completely absent in this area compared to 2005 and SAV is also absent around Neale Sound, just above Cobb Island.
POTOMAC RIVER - CUCKHOLD AND PICCOWAXEN CREEKS AND ADJACENT AREAS (CB Segment POTMH)
(Flight line 72; flown Aug. 23; Quad 067) - SAV is present but the overall abundance is less than in 2005. Most of the SAV is present at the upper reaches of these creeks.
POTOMAC RIVER - PORT TOBACCO RIVER (CB Segment POTOH)
(Flight lines 119, 120, 121; flown Oct. 3; Quad 057) -
SAV is present as a narrow fringe along both shorelines to the head of the river, similar to last year. SAV in Goose Creek is very dense.
POTOMAC RIVER - NANJEMOY CREEK (CB Segment POTOH)
(Flight lines 119, 120; flown Sept. 2; Quads 056, 057) -
SAV is very dense and abundant in this system especially in Hill Top Fork and Burgess Creek. Dense beds line the river to Blossum Point on the north side and Benny Gray Point on the south side but they are not as abundant in some areas as noted in 2005. There is apatchy SAV bed between Blossum Point and Upper Cedar Point on the mainstem but no observable SAV above this place all the way to Port Tobacco River. There are some SAV beds between Benny Gray Point and Maryland Point.
POTOMAC RIVER - POTOMAC AND AQUIA CREEKS (CB Segment POTOH)
(Flight lines 121, 122; flown Oct. 3; Quads 047, 048, 055, 056, and 064) -
There is some fringing SAV beds in Potomac Creek but nothing like what we have observed in previous years. However, Aquia Creek, immediately above Potomac Creek, is essentially covered with SAV from the mouth to the headwaters. Proceeding upriver along the mainstem, SAV is very dense from the mouth of Aquia Creek all the way to Quantico and into Quantico Creek.
POTOMAC RIVER - CHICAMUXEN AND MATTAWOMAN CREEKS (CB Segment, POTTF, POTOH, MATTF)
(Flight lines 125; flown Oct.; Quads 047, 048, 055, 056, and 064) - SAV is extremely abundant and dense in these systems, as well as the mainstem shoreline of the Potomac above and below these creeks.
POTOMAC RIVER - OCCOQUAN BAY AND BELMONT BAY (CB segment POTTF)
(Flight lines 126, 127, 128; flown Oct. 3; Quads 039, 048) - Occoquan Bay has little SAV, but interesting SAV is present behind several breakwaters which we noted last year. In Belmont Bay, SAV is abundant and very dense.
POTOMAC RIVER - NEABSCO AND POWELLS CREEKS (CB Segment POTOH)
Flight lines 126; flown Oct. 3; Quad 047) - Both creeks appear to have dense and abundant SAV.
POTOMAC RIVER VIRGINIA SIDE FROM 301 BRIDGE TO THE MOUTH (CB Segments POTMH, POTOH)
(Flight lines 76, 76A, 76B, 77, 78, 78A, 79, 80; flown Aug. 21, 22; Quads 057, 064, 065, 066, 067, 076, 077, 078, 087, 079, 080) -
SAV beds are essentially absent along the Virginia side from the mouth of the river to the 301 bridge, even in Popes Creek just below Colonial Beach, which had abundant SAV in 2005. There are some patchy beds on the shoals above the 301 bridge heading towards Mathias Point which similar to what we have noted in 2005.
POTOMAC RIVER - COAN RIVER (CB Segment POTMH)
(Flight lines 79, 80; flown Aug. 22; Quads 089, 097) - No SAV noted.
POTOMAC RIVER - YEOCOMICO RIVER (CB Segment POTMH)
(Flight lines 79, 80; flown Aug. 22; Quad 088) - SAV beds are reduced from last year and are only present in a couple of locations.
PATUXENT RIVER (CB Segments PAXTF, PAXOH, PAXMH, and WBRTF)
(Flight lines 62-65, flown Aug. 23, 24; Quads 041, 049, 059, 060, 061, 070, 071 and 159
) - In the Upper tidal freshwater Patuxent, SAV continues to thrive on the narrow shoals first noted in 1994, although the overall abundance appears slightly less than what was noted in 2005. Almost no SAV is observable in the lower portions of this river.
RHODE AND WEST RIVERS (CB Segments RHDMH, WSTMH)
(Flight line 58; flown Aug. 5; Quads 030, 035) - No SAV was noted this year.
SOUTH RIVER (CB Segment SEVMH)
(Flight lines 57-59; flown Aug. 5; Quads 030, 031) -
There is almost no SAV observable in this system. Field reports from Drew Koslow, the river shore keeper, have also noted little SAV.
SEVERN RIVER (CB Segment SEVMH)
(Flight lines 55-58; flown Aug. 5; Quads 023, 024, 031) -
SAV continues to be very robust in this system and similar to what we have observed in recent years. SAV beds are most abundant along the shorelines of Round Bay area, especially around Sherwood Forest into Little Round Bay, from Sullivan Cove past Asquith Creek down to Chase Cove. Small, patchy beds persist at the mouth of Weems Creek and Cove of Cork, adjacent to the Route 50 bridge.
MAGOTHY RIVER (CB Segment MAGMH)
(Flight lines 55-57; flown Aug. 5; Quads 023, 024) -
SAV in the Magothy River (home to Peter Bergstrom's numerous and detailed sightings), remain robust. The photography (we are going to refly the upper segments as there was a strange turbidity plume masking some of the SAV signals in the upper Magothy. SAV beds are present along the south shore from just east of the mouth of Deep Creek to Ulmsteads Point. Along the north portion of the Magothy, significant SAV beds are present along the west side of Gibson Island, Magothy Narrows, Inner Harbor, Cornfield Creek, and from the mouth of Cornfield Creek to Grays Point.
PATAPSCO RIVER AND TRIBS (CB Segment PATMH)
(Flight lines 52-53, flown Oct. 2 and 54-56, flown Aug. 5; Quads 012, 013, 018, 019, 024) - There are very few SAV beds in this section this year compared to last year. In Shallow Creek at the mouth of the Patapsco, (where Peter Bergstrom has conducted his transplanting), several smaller beds remain, primarily in the cove along the west side before you enter Shallow Creek. Some smaller beds are present but much less than in 2005 in Rock, Stony, Main, Back and Bodkin creeks. The dense beds reported in 2005 in Bear Creek appear to be absent this year. These beds and others in the Patapsco were reported to be dominated by milfoil.
BACK AND MIDDLE RIVERS AREAS (CB Segments BACOH, MIDOH)
(Flight lines 48A, 49A, 51; flown Sept. 13; Quads 013, 014, 019) -
There is no SAV in the Back River. SAV beds begin adjacent to Rocky Point Park and continue north into Browns Creek and into the Middle River, but SAV appears to be distinctly less in 2006. SAV is also in Seneca and Saltpeter creeks.
SUSQUEHANNA FLATS AREA (CB Segment CB1TF)
(Flight lines 43, 44, 44A; flown Oct. 2; Quads 002, 003, 004) -
NOTE - these lines only cover areas outside of the APG restricted area, which we have not flown as they only allow access on weekends. The main body of the Flats is surprisingly robust this year given the concerns expressed earlier regarding the rain event in June and the turbidity that persisted for a long period. The beds appear dense in many areas and grade to sparser areas as you move south. Beds appear again behind the 7 offshore breakwaters near "Camp Chesapeake" with patches noted north and south of these breakwaters. Dense beds are noted in Chara Cove. SAV is very dense in Furnace Bay. SAV is very dense along both shorelines of the Susquehanna River and around Garrett Island.
ELK AND BOHEMIA RIVERS (CB Segments ELKOH, BOHOH, C&DOH)
(flight lines 40, 41; flown Oct. 2; Quads 004, 005, 010, 011) -
SAV is really impressive in these two river systems! Beds cover almost all the shoal areas from the mouth to the top of the systems and are especially dense and abundant at the head of the Elk System. Some of the dense beds in the Bohemia noted in 2005 at the upper ends are reduced, though.
SASSAFRAS RIVER (CB Segment SASOH)
(flight line 39; flown Oct. 2; Quads 009, 010, 011, 016, 017, 199)
- SAV is present and abundant along the north shoreline from the mouth to Money Creek and along the south shoreline from the mouth to Turners Creek. SAV is present in Lloyd Creek but is not as abundant and dense as in past years. However, SAV beds are in general less abundant than in 2005.
MAINSTEM BAY FROM ROCK HALL TO SWAN CREEK (CB Segment CB3MH, CB2OH)
(Flight lines 33-37; flown Oct. 2; Quads 021, 022, 026, 027, 193).
CHESTER RIVER, INCLUDING EASTERN NECK NARROWS AND THE CORSICA RIVER (CB Segments CB3MH, CHSMH, CHSOH)
(Flight line 33; flown Oct. 2; Quads 015, 020, 021) -
SAV beds are abundant in Huntingfield Creek and present in two coves in Haven Harbor. No SAV is observable in the Haven or Swan Creek. SAV is notably reduced from much of this system in 2006 from what was observed in 2005. We have gotten some very detailed field reports from Terry Willis (reports are on our web site) and his observations support what we are noting from the aerial flights. Recovering beds noted in 2005 along the Eastern Neck Island and Narrows area has been reduced significantly in 2006 and now is present in only some sparse beds. SAV is present in Church Creek, but primarily along the eastern shoreline but is also less than in 2005. Robins and Middle Quarter Coves around the mouth of the Corsica River are the only other locations with significant populations of SAV. No SAV was noted in the Corsica River and many of the beds noted in the upper Chester River above Chestertown are not observable.
LITTLE CHOPTANK RIVER AND ADJACENT BAYS AND COVES (CB Segment LCHMH)
(flight lines 16, 16a, 17, 18; flown Sept. 26; Quads 051, 052, 062) -
SAV is noticeably absent in much of the Little Choptank, an area where widgeongrass dominated. SAV has reappeared in Trippe Bay although it is not as abundant as we have observed in previous years.
CHOPTANK RIVER (CB Segments CHOMH1, CHOMH2, CHOOH)
(Flight lines 22-26; flown Aug. 2; Quads 036, 037, 043, 044) - The most significant SAV beds are located beds in Cooks Point Cove, the mouth of Chapel Creek, a few areas in the Tred Avon River, Irish Creek, and lower portion of Broad Creek. All other areas that had abundant SAV (dominated by widgeongrass) including Harris Creek appear to be unvegetated. HPEL staff noted that much of this had died out this summer when it got extremely hot. This absence of SAV here is intriguing given the abundance of SAV along the south shore noted above!
EASTERN BAY AREA (CB Segment EASMH)
(Flight lines 22-32; flown Aug. 5, 24; Quads 032, 033, 036, 037) -
SAV is most abundant in the northern section of this region, with the most significant beds being in Marshy Creek and the coves along the north end of Kent Island. Other areas with significant amounts of SAV are in Crab Alley Bay and in Cox Creek. Much of the southern end of Eastern Bay, including the Miles and Wye rivers, do not have any SAV.
I visited Shallow Creek with Steve Ailstock by canoe on Monday 10/09/06.
Water was cloudy (0.4 m Secchi), possibly from the heavy rains and wind
the previous Friday and Saturday, and water levels were still about 0.5 foot
above normal due to that storm. Salinity was 7 ppt, which was probably
not depressed much by the storm because the watershed is so small.
Despite the murky water, we had no trouble seeing the dense patches of
wild celery (Va), redhead grass (Ppf) and milfoil (Ms) because they were
all growing to the surface.
This creek has two main areas of interest for SAV: one just inside a RR
causeway that used to cross the mouth of the creek, where we planted SAV
every year except 2002 from 1999-2003, and the outer cove just outside
that RR causeway, where we planted SAV on a more limited scale in
1999-2000, partly because I found natural beds of Va there starting in
1998. The aerial photo from 10/2/06 is marked to show where we
planted what and when. Our original planted clumps inside the RR
causeway (still visible in 2005, see below) have all coalesced and spread
towards the mouth of the creek. We also planted sago pondweed (Ppc) in
1999 and 2000, but none of it survived.
The photo and our field visit confirmed that the SAV beds in 2006 were
much larger and denser than they were in 2005, and that Va and Ppf that we
planted had persisted in both planting sites and spread to other parts of
the creek (see map from 10/9/06). This photo shows dense Va around the one pole that is left from the
2003 DNR planting; there was some Ppf in this bed but not visible here.
The SAV had spread into the shallows about as far as they could go, but
were depth limited to about 0.6-0.7 m deep at low tide, as expected given
the murky water.This was the first time I had
found Ppf away from the places where we planted it, and Va (both natural
and planted) had also spread into several new areas of the creek this
year. Before this year, the rest of the creek had almost exclusively
milfoil where it had SAV.
Finding Ppf this year was exciting because last year I thought the Ppf
that we planted was gone (see below). We never found any natural Ppf in
the creek before planting, and there are few beds of it in nearby creeks,
so we're pretty sure that all of it came from our planting. Since there
was some natural Va in the creek before we planted, we can't be sure how
much of it was due to our efforts, but I've never seen flowers or seeds
on the Va there. This means it may only spread vegetatively, which it
could not do around the RR causeway from the natural beds in the outer
cove. Since the last planting we did there was in 2003, it's possible
that the plants survived only 3 years, but the extent of the plants
inside the RR causeway suggest many of them have survived for 5 or 6
years. This is longer survival than any other small scale SAV planting I
have done; the record elsewhere is 3 years for Ppf. As to why the
planted Va & Ppf did so well in this creek, in spite of frequent low
water clarity, I can think of two reasons. It seems to have a salinity
range that allows both species to persist, which may be a key to long
term survival. It is also an unusual creek, very shallow with a small
watershed, right off the mainstem.
I last visited this creek on 9/22/05 when I found only Va inside the RR
causeway, and it was short and barely visible with a view scope. I
estimated only 25% cover of Va within the areas we planted, although the
planted squares were visible in the VIMS photo taken on 9/13/05. (see detail photo and http://www.vims.edu/bio/sav/2005_SAV_Photo_Gallery/images_original/52-2_sep13-05.JPG) I thought the Ppf we planted there was all gone, but apparently it
was just too short to see. I only found Ppf at one spot in the outer
cove. Secchi depth was also 0.4 m and the salinity was a bit higher, 10
ppt. The Va was so short I could only see one patch of Va without the
view scope, and in some places I felt for shoots by hand from my kayak,
something I've rarely done anywhere else.
I recently (September 21, 2006) surveyed SAV along a small portion of the
Occoquan Bay. I have been looking at the shoreline between Sandy and High
points for the past few years to monitor SAV growth around two sets of offshore breakwaters. Similarly to last year, fairly dense (cover 3 to 4)
SAV was found behind the breakwaters, and no SAV was observed offshore of
the breakwaters. The SAV behind the breakwater set closest to High Point
was dominated in places by Hydrilla, and in places by Vallisneria. N.
minor, H. dubia, C. dermersum, and M. spicatum were also found behind this
breakwater. In contrast to last year, between the breakwater set closest
to High Point and the breakwater set closest to Sandy Point, I observed a
sparse (cover 1) bed of V. americana and M. spicatum. The bed behind the
breakwater set closest to Sandy Point was codominated by Hydrilla and N.
minor and also included M. spicatum, C. dermersum, V. americana, and H.
dubia. I observed a sparse bed (cover 1) extending northwest along the
shoreline from the Sandy Point breakwater set which consisted of M.
Today (11/21/06) I kayaked on lower Weems Creek, Severn River to look
for Elodea that Nancy Rybicki requested to use for genetic analyses she
is doing of the Elodea/Hydrilla group. I went to the site (waypoint195)
where I found Elodea (Ec) in Weems Creek on 8/18/06, described here:
http://www.vims.edu/bio/sav/2006obs.html#noaa082306 (at "Lower Weems
Creek"--WPT 195 on that day) The tide was very low and the water was
quite clear today (why can't it be this low & clear in the summer??) and
at first I could only see milfoil (Ms). However after looking more
closely and raking I discovered that much of the shallows of the cove
were covered with prostrate Elodea, hard to see under sediment and
fallen leaves, but mostly still bright green. I collected about 1/2
gallon of shoots for Nancy's research.
In my report from August I attached a photo of the plants from that cove
but I did not speculate on what species they might be (Elodea canadensis
Ec or E. nuttallii En). Salinity was 11 ppt today, and it was 10 ppt on
8/18/06.. Based on the salinity, and the absence in the Severn of most
low salinity SAV species except slender pondweed (Ppu) (I've never found
wild celery there, for example), and the form of the plants compared to
the drawings in Brown & Brown, I strongly suspect that these are E.
nuttallii, since they tolerate higher salinity than Ec. If you have a
copy of the new SAV guide from Sea Grant, the plants from Weems Creek
(possible En) more closely resemble the middle of the three photos on
the Waterweed pages (the one with the quarter that looks less bushy with
more slender leaves), while the other two photos and the drawing on
those pages more closely resemble the drawing of Ec in Brown & Brown
(more bushy with wider leaves). I hope that Nancy's analyses will shed
more light on this issue.