Algae Bloom Sweeping Across Chesapeake Bay is the Largest in Years

Science World Report by Catherine Griffin – The researchers actually collected water samples near the mouth of the York River on Aug. 17. These samples contained up to 200,000 algal cells per millimeter, which is the densest concentration seen in nearly 10 years of field sampling.

The current blooms are dominated by a single-celled protozoan, called Alexandrium monilatum, which is an algal species known to release toxins that are harmful to other marine life, particularly larval shellfish and finfish.

“This is new and important information, as we have never appreciated that Alexandrium extends so far into the mainstem of the Bay or so far up the York River,” said Wolfgang Vogelbein, one of the researchers, in a news release. “The main body of the bloom is several miles off shore, and thus wasn’t appreciated prior to the recent flyovers.”

The algae that primarily makes up these blooms is one of several species of harmful algae that are of emerging concern in Chesapeake Bay. It was first detected in Bay waters in 2007. Since then, it seems to have spread.

Monitoring this algae is important when it comes to understanding the health of Chesapeake Bay. By understanding how large the bloom is, researchers can compare it to other years and see what conditions may have led to it. This, in turn, may help scientists ward against these conditions in the future.