Influence of Groundwater Constituents on Initiation of the Brown Tide in the Peconic Bay System (2003)

A combination of laboratory-based bioassays, manipulative field experiments and field reconnaissance were employed to evaluate the central hypothesis that chemical constituents introduced into coastal L.I. embayments by groundwater (GW) initiate Brown Tide outbreaks and investigated to see if these chemical constituents may act by directly stimulating growth of Aureococcus anophagefferens, the Brown Tide organism or by depressing growth of the Brown Tideês ecological competitors. The study concludes that submarine groundwater discharge can exert strong selective pressures on phytoplankton communities, depending upon its source and composition. The study further concludes that the likelihood of Brown Tide being initiated by introduction of the pesticides tested via submarine groundwater discharge is not supported by these results. Lab and field data support the hypothesis that seasonal changes in nitrogen speciation, and possibly elemental ratios (N:P:Si:Fe:Se), can alter competitive advantage between A. anophagefferens and its competitors.The study notes that additional investigations of the roles of pesticide metabolites and a few key trace metals is warranted for future studies.