Fisheries Behavioral Ecology - Abstracts
Hurst, T.P., K.A. McKown, and D.O. Conover. 2004. Interannual and long-term variation in the nearshore fish community of the mesohaline Hudson River estuary. Estuaries 27:659–669.
Abstract
The detection of long-term shifts in species composition and spatial structuring of aquatic communities
may be obscured by high levels of interannual variation. Estuarine fish communities are likely to exhibit high levels of
variation owing to the influence of riverine forcing and the importance of anadromous and transient species, whose
abundances may not be locally controlled. We describe patterns of interannual variation and long-term shifts in the
nearshore fish community of the mesohaline Hudson River estuary based on 21 yr of beach seine sampling conducted
annually between late August and mid November. Of the 60 species encountered, the most abundant were Atlantic
silversides (Menidia menidia), striped bass (Morone saxatilis), white perch (Morone americana), American shad (Alosa sapidissima),
and blueback herring (Alosa aestivalis). Relationships between annual community composition and seasonal
flow and temperature regimes were examined with canonical correspondence analysis. Annual variation was most closely
correlated with river flows in the 3-mo period preceding fish sampling, indicating a persistent effect of environmental
conditions on community structure. Despite significant interannual variation in composition, longer-term trends in community
structure were observed. These included declines in catch rates of freshwater and estuarine species and a dramatic
increase in the catch of Atlantic silversides, an annual marine species. Associated with these changes were declines in
community diversity and increased compositional variation. These results indicate that analyses of temporal changes in
community structure need to account for the multiple time scales under which forcing factors and community composition
vary.
Last updated
26 April, 2007
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