Spatial and Temporal Variability in Zooplankton Community Dynamics in Three Urbanized Bayous of the Pensacola Bay System, Florida, USA

Spatial and temporal patterns in zooplankton community composition and abundance in coastal areas of the Gulf of Mexico are not well understood. Spatial and temporal differences in zooplankton community composition and abundance from 10 stations located in four sites are presented (Pensacola Bay and Bayou Texar, Bayou Chico, and Bayou Grande, three adjacent mesohaline-tidal bayous affected by urban and industrial development). Statistically significant differences (P < 0.05) were found in log-biovolume among sites. The mean biovolume of zooplankton was highest in Pensacola Bay (0.38 ml m-3) followed by Bayou Grande (0.21 ml m-3), Bayou Chico (0.14 ml m-3), and Bayou Texar (0.06 ml m-3). Mean zooplankton abundances (organisms m-3) in Pensacola Bay (3,100 m-3) and Bayou Grande (3,000 m-3) were more than double the abundances in Bayou Texar (1,400 m-3) and Bayou Chico (1,100 m-3). The calanoid copepod Acartia tonsa Dana was the dominant species in the study area. The observed differences in the zooplankton community may be attributable to either one or a combination of factors such as water quality (toxicity), predation, and nutrient availability. Zooplankton abundance increased following two hurricanes that impacted the study area.