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Investigations of toxic red tides and groundwater nutrient fluxes in the Nauset Marsh Estuary, Cape Cod National Seashore


PIs Donald M. Anderson, David Ralston

This project is combining detailed field and laboratory studies to examine the population dynamics of harmful algal blooms (HABs) in the Nauset Marsh Estuary (NME), and relate hydrodynamics, and groundwater nutrient fluxes to HAB duration and intensity using an existing physical-biological numerical model. HABs (commonly called “red tides”) cause devastating impacts to local economies, public health, and ecosystems throughout the world. In the U.S., the most serious and widespread manifestation is paralytic shellfish poisoning (PSP), a syndrome caused by human ingestion of shellfish that accumulate toxins from dinoflagellates, predominantly in the genus Alexandrium. In Massachusetts, PSP caused by red tides is annually recurrent along the coastline, including within a number of small embayments and salt ponds on Cape Cod. One such system within the Cape Cod National Seashore is the salt marsh dominated NME, providing estuarine nursery support functions and supporting a thriving shellfishing industry. Since the 1970’s, the NME has experienced annual episodes of Alexandrium blooms that are initiated and most intense in the landward extensions of the estuary. These are also the locus of maximum groundwater and associated nutrient discharge to the system. Notably, the characteristics of the PSP problem in the NME have changed in a dramatic and negative manner over the last two decades. PSP occurred in Salt Pond (NME) in 8 of 17 years (48%) from 1975 to 1991, and then in 18 of the last 19 years (95%), in some cases resulting in shellfishing closures (and loss of jobs) for over several months.

Relevant Publications:

Anderson, D.M., D.M. Kulis, B.A. Keafer, and E. Berdalet. 1999.  Detection of the toxic dinoflagellate Alexandrium fundyense (Dinophyceae) with oligonucleotide and antibody probes: variability in labeling intensity with physiological condition.  J. Phycol. 35: 870-883.

Anderson, D.M., J.M. Burkholder, W.P. Cochlan, P.M. Glibert, C.J. Gobler, C.A. Heil, R. Kudela, M.L. Parsons, J.E. Rensel, D.W. Townsend, V.L. Trainer, and G.A. Vargo. 2008. Harmful algal blooms and eutrophication: Examining linkages from selected coastal regions of the United States. Harmful Algae 8: 39-53.

He, R., McGillicuddy, D.J., Keafer, B.A. and D.M. Anderson. 2008. Historic 2005 toxic bloom of Alexandrium fundyense in the western Gulf of Maine: 2. Coupled Biophysical Numerical Modeling. Journal of Geophysical Research-Oceans, 113, C07040, doi:10.1029/2007JC004602.

McGillicuddy, D.J., Jr., D.M. Anderson, D.R. Lynch, and D.W. Townsend. 2005. Mechanisms regulating large-scale seasonal fluctuations in Alexandrium fundyense populations in the Gulf of Maine: Results from a physical-biological model. Deep-Sea Res. II 52(19-21): 2698-2714.

Portnoy, JW,BL Nowicki, CT Roman, and DW Urish, 1998. The discharge of nitrate-contaminated groundwater from developed shoreline to marsh-fringed estuary, Water Resources Research 34:11:3095-3104.

Stock, C.A., D.J. McGillicuddy, A.R. Solow, D. M. Anderson. 2005. Evaluating hypotheses for the initiation and development of Alexandrium fundyense blooms in the western Gulf of Maine using a coupled physical-biological model. Deep-Sea Res. II 52(19-21): 2715-2744.