Dead zones and algal blooms tend to be especially bad in the Bay over the summer months. Dead zones are areas where excess nutrients in the water- nitrogen and phosphorus runoff from human activity- create oxygen depleted underwater areas, where fish and other aquatic organisms find it difficult to survive. Algal blooms occur in waters with excess nutrients. The blooms block sunlight to submerged aquatic vegetation. Underwater grasses cannot grow and survive in these conditions, and cannot provide food or shelter for a number of reliant species.
Scientists predicted in June that there would be an above-average dead zone in the Chesapeake Bay this summer. There is good and bad news on that front. In July, the Bay’s dead zone was the smallest recorded in 30 years, according to the Capital Gazette. Hurricane Arthur and cooler than average temperatures in July were likely the main factors. However, it is predicted that this trend will not last through August. Warmer temperatures, and the spread of algal blooms already spotted in the Bay and its tributaries will lead to more serious conditions later this summer.
-Researchers at William and Mary, and the Virginia Institute of Marine Science (VIMS), are working on an algae biofuel initiative, which harvests algae as fuel, and takes up excess algae and nutrients in the water that create dead zones and harmful blooms. There is an interesting article in the Biomass Magazine, which goes into more detail on this project.
–The Chesapeake Bay Program recently published a photo essay that documents how researchers at the University of Maryland Center for Environmental Science (UMCES) record dead zones in the Bay. UMCES uses a research vessel to go out to the deepest parts of the Bay and perform a number of tests, including the measurement of dissolved oxygen levels.