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Routine water quality monitoring on June 2 by Maryland Department of Natural Resources (DNR) detected low concentrations of the potentially toxic dinoflagellate Dinophysis acuminata in Marylands Coastal Bays. There is no evidence of toxicity at this time. No fish kills, living resource or human health events have been associated with the bloom locations so far this season. Dinophysis was recorded in low concentrations on Turville Creek, Manklin Creek and Isle of Wight Bay with concentrations of 4,000, 6,000 and 5,000 cells/liter, respectively. Water quality data collected by DNRs continuous monitoring station in Turville Creek during the first two weeks of June show increasing levels of chlorophyll (an indicator of the amount of algae active in the water) and corresponding declines in dissolved oxygen. This type of combined behavior in chlorophyll and dissolved oxygen are often characteristic of algal bloom activity. However, Dinophysis blooms by themselves would not be responsible for such activity as their numbers are low compared to all the other algae. DNR will continue to monitor these areas throughout the year. Around the world, blooms of Dinophysis species including D. acuminata can sometimes lead to toxic shellfish events. Shellfish in the area of a bloom can accumulate the okadaic acid toxins or derivatives of the toxin when feeding on the algae but not killing the shellfish. Diarrhetic Shellfish Poisoning (DSP) has occurred in humans consuming the contaminated shellfish, resulting in symptoms that include intestinal discomfort, abdominal pain, nausea, headache, chills and vomiting. DSP from Dinophysis species has not been confirmed in U.S. seafood, although the organisms are widespread in the U.S. Europe and Japan appear to be the most highly affected areas for cases of DSP. Despite thousands of documented cases of DSP worldwide since 1960, there are no reported fatalities associated with the illness. During the winter of 2002, Dinophysis acuminata was detected on the lower Potomac River at elevated concentrations (6,000-44,000 cells/l) causing the temporary closure of shellfish waters in that area. Toxicity testing by the U.S. Food and Drug Administration only detected trace amounts of okadaic acid in the shellfish and algae allowing the fishery to reopen. For up to date information on all of Maryland's harmful algal blooms and water quality, please visit Eyes on the Bay |