Phytoplankton and Pink Oysters in Galveston Bay

Galveston Bay (GB) supports a large commercial fishery for the Eastern oyster (Crassostrea virginica), with annual harvests presently approaching 400 metric tons. Oystermen have recently expressed concern over a peculiar red/pink coloration of oyster meats that frequently occurs in oysters from some commercial reefs in GB. This unique pigmentation is referred to as the pink oyster phenomenon. Although the conspicuous color has no immediately apparent effect on oyster condition and is not known to pose a human health hazard, the coloration adversely affects consumer acceptance and hence the marketability for both the shucked and half-shell trade. Bay oystermen report that pink oysters have occurred sporadically over the last 14 years during October to January. The intensity of events varies from year to year. The number of pink oysters harvested by commercial oystermen was monitored in the 1999-2002 seasons. Preliminary field and laboratory evidence suggested that this coloration may be caused by the phytoplankton upon which the oysters were feeding..... Understanding the linkages between system-level driving features for phytoplankton blooms is highly relevant for oyster fishery management and commercial harvests in GB. This estuary, like many others in the Gulf of Mexico, supports large recreational and commercial fisheries. Significant changes in the phytoplankton community composition resulting from increasing nutrient loadings and concentrations could have major impacts on higher trophic levels in GB. Therefore, a thorough understanding system level responses to the anthropogenic factors (e.g., nutrients, pollutants, xenobiotics, etc.) that regulate phytoplankton species and biomass dynamics is a prerequisite for developing effective mitigation and management strategies for Galveston Bay and similar shallow estuaries in the Gulf of Mexico.