News and ResourcesMaryland Coastal Bays Report Card - 2013 - August 31, 2014
In 2013 the coastal bays had an overall health rating of C+, a bit better than the C+ in previous years. While there are certain water quality conditions that are relatively good there are still major problems that need to be improved to protect the health of the bays and the local economy they support.
The health of each embayment; Sinepuxent, Chincoteague, Assawoman, Isle of Wight, and Newport bays along with the St. Martin River are each graded using multiple indicators. These indicators include the total Nitrogen and Phosphorous in the water, chlorophyll a, dissolved oxygen levels, seagrass coverage, and hard clam populations. These indicators help us assess the general water quality for the bays and rivers which allows us to create a grading scale to evaluate the health of the individual and coastal bay areas as a whole.
The two areas with the lowest individual grades were St. Martin River and Newport Bay; they each received a D+ rating. St. Martin River had the lowest scores for Phosphorus, chlorophyll a, Nitrogen and seagrass coverage in the entire coastal bays watershed and has seen significant declines in overall health over the past few years. Newport Bay has the worst overall health of any subembayment, mostly because it had a decline in seagrasses, dissolved oxygen and in increase in excess Phosphorous. These declines offset the recent gains in this area of chlorophyll a, hard clams and a decrease in excess Nitrogen.
Assawoman and Isle of Wight bays both received C ratings, indicating that while they were not in horrible shape they could still use serious improvements. The Isle of Wight Bay varied tremendously in water quality indicator status. There were significant improvements in dissolved oxygen and chlorophyll a, however these were offset by increases in excess Phosphorous and a decrease in hard clams and seagrasses. Assawoman saw a slight improvement of overall health since 2012 however an increase in excess Phosphorous and a decrease in chlorophyll a and seagrass coverage still hurt its overall grade.
Chincoteague Bay received another B- rating, keeping its score steady for the past two years. There were some small declines in hard clams, seagrass coverage and chlorophyll a, however there were major improvements in dissolved oxygen and lowering the levels of excess Nitrogen and Phosophorous. Unfortunately this area has consistently had the lowest hard clam population in the coastal bays region over the past few years, possibly due to reoccurring brown tides.
Sinepuxent bay received another B- rating this year, having some of the best overall scores of all coastal bays. While this bay was tied for the best overall health compared to the other bays there was still room for improvement. Nitrogen and cholorphyll a were excellent this year, while dissolved oxygen, ecess Phosphorous, hard clams and seagrasses all had at least a moderate to good rating.
While we make strides in controlling the amount of excess Nitrogen and Phosphorous that enters our watershed via runoff we still have a major problem with excess nutrients in our groundwater. Groundwater is extremely important because it provides us with drinking water, is used for irrigation by farmers, and helps recharge rivers, streams, lakes and other bodies of water. Unfortunately this water is being contaminated with historic nutrients from septic systems, agriculture, and developed land. Groundwater discharge adds these nutrients into our streams and rivers and this eventually leads to those nutrients being added to our coastal bays. Because groundwater recharge is slow, it is estimated that even if we capped our nutrient use today there would still be no major changes in nutrient levels in groundwater discharge for 20 to 30 years.
A reduction in seagrass coverage was seen throughout the coastal bays region and can often be linked with lower levels of dissolved oxygen in the water. The continual degradation of water quality and water clarity are the main factors for seagrass loss and overall seagrass coverage continues to decline throughout all the bays and their tributaries, just like it has for the past few years.
Hard clam populations went up dramatically in certain areas, such as Isle of Wight, the population of these bivalves is well below historic levels in most of the coastal bays. This could be due to a variety of reasons including poor water quality, harmful brown algae blooms and increased predation.
While a C for the overall health of the bays is worrisome it should not be seen as the beginning of the end but a chance to show how resilient and committed we are to saving our coastal bays.
If you would like to view the Coastal Bays report card, it is available on the Maryland Coastal Bays Program website, www.mdcoastalbays.org
Harrison Jackson is the Coastal Stewards Coordinator for the Maryland Coastal Bays Program.
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