The tidal portion of the Hudson River, New York, showing areas where some fish collections have been made over the last six decades. I explore differences in the nearshore fish assemblages of the Hudson River by comparing information on the distribution and abundance of fish collected between 1936 and 1990. This comparison offers only a coarse look at change in the fish assemblage and provides little information on trends. The nearshore fish assemblage of the Hudson River is dynamic and changes on a daily, seasonal, and annual basis. The watershed surveys of New York conducted between 1926 and 1939 included a detailed survey of fish distribution and abundance in the lower Hudson River drainage.
Data collection continues in many of the long-term programs.
Because techniques and equipment vary among the surveys, I have included in the analyses only information collected by workers using seines. Still, the size of the seines used, the mesh size, and the area sampled differ among the surveys and contribute a bias not easily quantified. Because this analysis is relatively coarse, any biases that may exist in the data should be masked. Furthermore, in most of the analyses I have made comparisons within data bases. Comparisons between data bases are used primarily with presence and absence applications.