Working together to keep today's treasures for tomorrow slide image Protecting the natural heritage of this diverse estuary slide image Promoting water quality and land preservation slide image Supporting a rich ecosystem for our local economy and quality of life slide image Managing our natural resources through consensus building slide image

News and Resources

Bottom of our bays tops list of priorities - July 1, 2013

When we think about the world’s oceans, lakes, bays and rivers, we generally tend to focus on the surface waters — basically about as far as we can see down the water column depending on clarity and turbidity.­

For centuries, mankind knew mostly about surface waters; collecting benthic and deepwater samples with nets and containers was difficult and expensive, and we never got a full view of what exactly happens on the bottom of our deepest bodies of water. But just because the benthic community is out of sight, it does not mean it is out of mind.

As technology progresses, we have the ability to see the benthic community in a new light through submersibles, Scuba diving and cameras. What we have seen so far has been astounding. Huge hydrothermal vents, actual footage of giant squids and animal species so bizarre they look like they came out of science fiction are all discoveries made with new marine technology.

Due to the fact that we know more about the surface of the moon than we do about the bottom of our oceans, odds are we will continue to find new and astounding things as our technology further advances.

In our coastal bays, there are numerous different types of Benthic communities, but the biggest and most vital systems include the Submerged Aquatic Vegetation (SAV) beds, oyster reefs and shell/debris cover. Unfortunately, during the past few decades, we have been steadily losing both SAV beds and oyster reefs due to poor water quality.

Once these benthic communities disappear, they are usually replaced with an infestation of macroalgae and seaweed. Macroalgae and seaweed benthic communities lack the ability to support large populations of animals or even a large biodiversity of animals, meaning that many of our key species in the bays and directly off our coasts are at risk.

SAV beds were historically among the most important benthic communities our costal bays had. These crucial habitats have been steadily shrinking since approximately 1999 due to a degradation of water quality. As phytoplankton populations bloom in the summer due to an excess of nitrogen in the water, the amount of sunlight that reaches the bottom significantly decreases.

SAVs are plants, which means they need sunlight in order to carry out photosynthesis to live. By cutting off their source of sunlight with phytoplankton blooms and turbid water, these important grasses start to die off. SAV beds are crucial habitat for numerous animals in our coastal bays, including blue crabs, grass shrimp, bay scallops, sea horses, pipefish and other young and juvenile oceanic fish species.­

As more SAVS are planted in a certain area, they will hold down sediments and absorb nutrients that would otherwise cause plankton blooms, which in turn increases water clarity and the amount of sunlight available on the bottom of our bays. This helps the SAVs grow and reproduce.

Another major benthic community type that has historically been very important in our coastal bays and rivers is the oyster reef. These reefs are crucial not only for habitat, but also for the filtering abilities of the oysters and other bivalves.

A single oyster can filter almost 50 gallons of water a day. However, if they are stressed or diseased, this number drops dramatically. Unfortunately, due to the opening and maintaining of the Ocean City Inlet for commercial and recreational use, the salinity levels in our coastal bays increased to a point where the oyster populations were severely stressed and under constant pressure.

The high salinity of our coastal bays after the opening of the Ocean City inlet led to an influx of diseases, such as MSX and Dermo, oyster predators and competitors. Due to these factors, among many others, the oyster population in the coastal bays will probably never be as large as it once. Despite this, there are still efforts from many organizations to help keep oysters in our coastal bays, the biggest of which involves growing oysters on floats or near docks or jetties in the coastal bays or larger rivers.
 

Harrison Jackson is the Coastal Stewards coordinator for the Maryland Coastal Bays Program.


To view article click here

Archived News

More Archived News
View Current News

U.S EPA News Region 3

Coastal Bays Program
Coastal Bays Program
Coastal Bays Program
Coastal Bays Program
Coastal Bays Program
Coastal Bays Program
Coastal Bays Program
Coastal Bays Program
Coastal Bays Program
Coastal Bays Program