Zooplankton in Advective Environments: The Hudson River Community and a Comparative Analysis

Abstract

The temporal dynamics and spatial distributions of zooplankton in the tidal freshwater portion of the Hudson River were studied over a 3-yr period. We tested the hypothesis that advective transport regulates zooplankton biomass in the Hudson and in lakes, estuaries, and rivers for which we have published values. In the Hudson, zooplankton biomass was negatively correlated with discharge over the entire season (P < 0.0001) as well as during the warmer period of the year (P = 0.007) when biomass was greatest. The spatial distribution of zooplankton over 160-km transects was heterogeneous. Downstream changes in the abundance of a dominant species, Bosmina longirostris, indicate that certain areas of the river support net population growth whereas other areas are population sinks. We infer that zooplankton biomass in the Hudson is a function of the balance between reproduction determined by resources and losses due to advection. Zooplankton biomass differs among lakes, estuaries, and rivers in a manner consistent with the differences in water residence time. Biomass is highest in lakes, lower in saline estuaries and tidal rivers, and lowest in rivers. Advective losses appear to be important in explaining differences between planktonic communities in lentic and lotic environments.

Lake St. Clair Zooplankton: Evidence for Post-DreissenaChanges

“…Short water residence times are believed to limit zooplankton biomass (Pace et al 1992). After the zebra mussel invasion in the Hudson River, phytoplankton biomass declined 80-90% and total zooplankton biomass declined over 70% (Pace et al 1998).…”

Population dynamics of Pseudomonas sp. along a spatial gradient of phosphate: an experimental approach for spatial ecology

“…Zooplankton, on the other hand, should be affected by the circulation dynamics of estuaries (flow dependent distribution). Pace et al (1992) detected flow dependent sourcesink patterns on the distribution of Bosmina along six stations on the Hudson River estuary, with a 30 x higher abundance in station 1 (up river) and a linear decrease seawards.…”

“…As a result, peak of abundance should shift from nutrient-rich habitats to regions away from the borders. In estuaries, the importance of water circulation on the spatial distribution of planktonic populations has been long recognized (Ketchum, 1954;Pace et al, 1992). This effect, however, is dependent on the relative scales of population growth and water turnover (Ketchum, 1954).…”

A floodplain-scale lake classification based on characteristics of macroinvertebrate assemblages and corresponding environmental properties

“…The TP-Chl a relationship was generally a linear function (Nicholls and Dillon, 1978;Schindler, 1978;Brown et al, 2000). However, in the lotic waters associated with river, Chl a was usually found to be influenced more strongly by water flow than nutrients (Pace et al, 1992;Tockner et al, 1999a;Lewis et al, 2000). The distinct relationships of log 10 TP-log 10 Chl a in five types of Yangtze lakes are compared (Fig.…”