Distribution and Abundance of Bay Anchovy Eggs and Larvae in the Hudson River and Nearby Waterways

摘要

Our objectives were to examine the distribution and abundance of bay anchovy Anchoa mitchilli eggs and larvae in the Hudson River and nearby waterways and to determine if past conditional mortality rate (CMR) estimates for bay anchovy entrained at Hudson River power plants may be substantially biased because they were based solely on sampling in the Hudson River. We addressed these objectives by comparing ichthyoplankton samples collected in the Hudson River with those collected in New York Harbor, the East River, and Long Island Sound using the same gear during 2002. Bay anchovy eggs were collected from late April through the end of sampling in the Hudson River (early October) and through the end of sampling in nearby waterways (late July). Bay anchovy larvae were collected from early June through end of sampling in both the Hudson River and nearby waterways. The highest densities of bay anchovy eggs and larvae in nearby waterways were about 13 and 14 times greater, respectively, than the highestdensities in the lower Hudson River. The peak standing crops of bay anchovy eggs and larvae in nearby waterways were about eight times larger than those in the Hudson River. Therefore, past CMR estimates for bay anchovy entrained at Hudson River power plants may be substantially biased if the bay anchovy eggs and larvae collected in the Hudson River and nearby waterways during 2002 belonged to one population, as it appears they did, and 2002 was representative of other years.