shallow water
...key features of Virginia's bays and estuaries
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Introduction

Shallow subtidal waters often bound with life.  A patch of bottom no larger than a beach towel may be home to billions of beneficial microbes, hundreds of thousands of small invertebrates, dozens of clams, and luxuriant meadows of underwater grasses. During much of the year, the waters above are teeming with a rich plankton soup and sometimes a few jellyfish. Small fish and crabs come and go to feed and hide from larger predators.  Birds may stalk from above, while larger fish may swim into shallow waters at high tide to find a meal.

shallow water cross section marshes macroalgae benthic microalgae sea grasses bacteria macrofauna nekton

Did you know that the shallow waters of estuaries and bays are among the most productive habitats on earth?  High availability of sunlight allows a variety of primary producers, such as algae and submerged aquatic grasses, to flourish. These organisms get their energy from sunlight and help to form the base of estuarine and coastal food webs.  Marshes often fringe the shorelines along protected estuaries and coasts and may contribute organic matter to local food webs.  Nutrients and organic matter from the land also don’t have far to travel to reach these habitats.

Shallow water habitats provide a variety of ecological services that directly benefit humans.  They help to improve water quality and serve as nursery grounds for fish and crabs. The high productivity of shallow estuarine habitats makes them economically important to humans, but anthropogenic (human-caused) activities can also stress these regions. Activities such as urbanization, shoreline modification due to the construction of docks and bulkheads, nutrient enrichment and reduced light resulting from erosion of sediment on the uplands may all disturb shallow water habitats.  They are also influenced by commerce and national defense within the estuaries, ports and harbors along our coasts.

These following sites provide additional information on shallow water habitats of estuaries and coasts:

 


 

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Department of Biological Sciences | School of Marine Science | Virginia Institute of Marine Science | The College of William and Mary | Gloucester Point, VA 23062