Summer HABs in Maryland Chesapeake Bay

1. Summer HABs in Maryland Chesapeake Bay + forecast assessment and other data Prepared by: Richard Lacouture & Ann Marie Hartsig Morgan State University Estuarine Research Center and the data of Walter Butler MDDNR Ben Longstaff & Cathy Wazniak

2. Microcystis aeruginosa in Potomac River • The M. aeruginosa bloom in the Potomac River during the summer of 2008 was relatively intense and widespread for a short period of time. • The bloom was first seen in a sample from Possum Point on 7/15. • Densities increased slightly on 7/21 but not the areal extent of the bloom. • The next sampling on 8/11 turned out to be the peak of the bloom both areally and in terms of cell numbers which peaked at ~100,000 cells/ml. • The bloom dissipated somewhat on 8/18 both in terms of its spatial dimension and the density of cells in the surface layer. • The bloom was virtually non-existent on 8/25 with the exception of Mattawoman Creek which still contained relatively low cell densities. • Those cell densities persisted in Mattawoman Creek on 9/8. • Toxicity tests taken from samples in early and mid-August indicate relatively high concentrations of the toxin, Microcystin. • In addition, there were high densities of M. aeruginosa in the upper Transquaking River area (>40,000 cells/ml) on the Eastern Shore.

8. Microcystis Bloom- August 8/19/08

9. Microcystin Results

10. Forecast - methods • Peter Tango • Change in methods compared to previous years • Based on % samples collected by MD DNR and river flow

11. Forecast - DNR sampling • 1 bloom sample collected on 8/11 • Observed large bloom in Mattawoman Crk: > 1 million cells per ml • Health warning by Charles Co Health Dept.

12. Forecast - accuracy • Based on MD sampling – over estimate • Consider MSU sampling – “perfect”! • Change methods to include MSU data?

13. Karlodinium veneficum in MD Chesapeake Bay and tribs • Summer, 2008 was a fairly ‘mellow’ period for blooms of K. veneficum. • June proved to be the peak bloom period with high densities in Patapsco River (>50,000/ml) and near the westernshore of the Bay across from the mouth of the Choptank River and in the Potomac River (>30,000/ml). There were a number of other areas with intermediate cell densities of this dinoflagellate during June. • There was very little bloom activity in July. • August and early-September were characterized by isolated blooms of fairly high densities in Patapsco River and Corsica River (>30,000/ml).

17. Two samples collected on April 29 and April 30 from station (XJI2396) at Budd's Landing on the Sassafras River had high cell counts of Pseudoanabaena (3,317,421 cells/ml and 3,843,251 cells/ml, respectively).

19. Prorocentrum - Forecast • Jon Anderson • 7 regions • CART analysis – flow, clarity, temp and salinity • Bloom size - fuzzy logic

20. Prorocentrum - Forecast • Patuxent River - late June to early July • Choptank River and Bay Bridge – late June • No blooms in the late summer and fall period

21. Prorocentrum Bloom ‘Mahogany tide’ mid-April through May Potentially toxic dinoflagellate Venerupin Shellfish Poisoning (VSP) No fish kills 2008 5/15/08

22. 5/20/08

23. Prorocentrum - Observed • Based on the Eyes on the Bay website • No blooms (>4500cells/ml) in June – August period • Low density counts in many of the areas predicted to have blooms