Frequently Asked Questions (FAQ)
How do I:
Download data or maps:
To download a table to use in a spreadsheet, click the frame in which the table is displayed. Using your browser, save the frame ( using a command such as "Save Frame As"). You can open this saved HTML file in a spreadsheet program. You can download entire files of maps or charts by downloading the PDF files (Adobe Acrobat) from the "Download" section of the home page.
Print maps, text, and tables?
To print the contents of a frame (text or data), click on the frame to select it, then use your browser's print button. To print out clear versions of the maps, use the button. You can also download the PDF maps using the "Downloads" button from the home page.
Compare 1999 SAV area to last year's distribution?
When viewing a quadrangle map, press the button. This will display a map showing where the SAV was located in both years. Green indicates spread of SAV, while red indicates a loss between the two years. You can also press the button to view the 1998 distribution alone.
Data tables showing the change between 1998 and 1999 are in the data frame of the quadrangle map page. This information is also in the Data section entitled "Area by Quadrangle".
View previous years' data?
Entire reports from 1994 through 1997 (except 1996) are also available online. These can be accessed directly through the VIMS SAV home page (press the SAV Home page button on the banner, then click on the link to each year's report). Also, when viewing a quadrangle in this report, you can press the button which displays the 1998 distribution. On that 1998 map, there is a link to the previous year's map. Entire GIS coverages for most years (1971-1999) are also available from the "SAV Distribution Data Archive" link on the SAV home page.
Find out about the ground surveys (species abbreviations, surveyors, dates surveyed, etc.)?
Ground survey data are displayed in the table data frame of the detailed segment and detailed quadrangle maps. This information includes species found at each location, who surveyed it and when. Locations for observations can be found on the detailed quadrangle map. Symbols identifying surveyors and abbreviations for the species can be found in the map key - press the button on the quadrangle maps to view it.
Convert hectares to acres?
To Convert: Multiply By: To Obtain: Hectares 10,000 Square meters Hectares 2.471 Acres Acres 0.4047 Hectares Acres 4,047 Square meters Square meters 10.76 Square feet
Change the size of the frames?
You can change each frame size (except the banner frame) by dragging the vertical frame bar left or right.
Find the total amount of SAV in a zone, segment or quadrangle?
SAV zone, segment, or quadrangle totals are found in the table frame on the zone map, segment maps, or quadrangle maps. Data summaries are found in the "Data Tables and Charts" menu.
Cite this report?
This report should be cited as the following: Orth, R.J., D.J. Wilcox, L.S. Nagey, J.R. Whiting, and J.R. Fishman. 2000. 1999 Distribution of Submerged Aquatic Vegetation in the Chesapeake Bay and Coastal Bays. VIMS Special Scientific Report Number 141. Final report to U.S. EPA, Chesapeake Bay Program, Annapolis, MD. Grant No.CB993777-02-0, http://www.vims.edu/bio/sav/sav99
SAV Restoration Target Goals (e.g. Tier I, II, and III)?
The Chesapeake Bay Program has adopted a three-tier goal for SAV restoration (Batiuk et al. 1992; Chesapeake Executive Council, 1993).
TIER I: Restoration of SAV to areas previously vegetated as mapped through regional and baywide aerial surveys between 1971 to 1990. This includes a baywide area of 46,025 hectares (approximately 114,000 acres). In this report, SAV totals are compared to the Tier I goal.
TIER II: Restoration of SAV to all shallow water areas delineated as existing or potential SAV habitat down to 1 meter depth mean low water (MLW), excluding areas which are unlikely to support SAV based on historical observations, survey information, or exposure regimes.
TIER III: Restoration of SAV to all shallow water areas delineated as existing or potential SAV habitat down to a depth of 2 meters MLW, excluding the same areas as Tier II and excluding several additional areas that are between 1 and 2 meters.