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Chattonella cf. verruculosa, a potentially toxic algal species, was present at elevated bloom densities of 69,695 cells/ml on July 18th in the Upper St. Martin River. Water quality data collected by MD DNRs continuous monitoring station on the Bishopville Prong showed elevated concentrations of chlorophyll (an indicator of the amount of algae active in the water) and declines in dissolved oxygen, indicative of algal bloom activity in the region. Chattonella is a potentially toxic Raphidophyte (golden brown algae) capable of producing a neurotoxin (brevetoxin) and has been associated with fish kills in other areas of the world. This species was implicated in large fish kill events in Delawares Coastal Bays in 2002; however, no fish kills were associated with Marylands Coastal Bays bloom location at this time. Another potentially toxic Raphidophyte, Heterosigma akashiwo, was identified in Newport Bay (Coastal Bays) during routine water quality monitoring on July 19th. Samples collected from the Heterosigma bloom on Trappe Creek contained 6,095 cells/ml. No fish kills were observed for this bloom location. An earlier Heterosigma bloom was present at bloom densities of 13,250-18,000 cells/ml on Ayers Creek (Newport Bay) during routine monitoring in mid-June (see HAB News from June 23, 2005: "Heterosigma akashiwo bloom detected in Ayer's Creek, Coastal Bays.") Samples collected from this bloom tested negative for toxic activity. Maryland DNR will continue to monitor these blooms. For up to date information on all of Marylands harmful algal blooms and water quality monitoring results, please visit Eyes on the Bay at www.eyesonthebay.net |