Age‐0 Black Crappie Abundance and Size in Relation to Zooplankton Density, Stock Abundance, and Water Clarity in Three Florida Lakes

Abstract

Crappies Pomoxis spp. are popular sport fishes but are often difficult to manage due to highly variable recruitment. To assess the factors influencing recruitment, we investigated the size and abundance of age‐0 black crappie P. nigromaculatus in relation to zooplankton density, adult stock abundance, and water clarity in three productive Florida lakes. Age‐0 black crappies were collected at Lakes Wauberg, Lochloosa, and Tarpon by use of surface and bottom trawls during the spring, summer, and fall of 2000 and 2001. Zooplankton abundance was measured concurrently with trawl sampling. Early‐summer juvenile abundance was positively related to stock abundance during the previous fall among lakes, indicating a relationship between stock size and juvenile black crappie abundance. Early‐summer juvenile abundance was positively related to juvenile abundance in the fall (i.e., at the end of the first summer), suggesting that year‐class strength was set by early summer in all lakes. Lake Lochloosa had the highest crustacean zooplankton abundance in both years, but this lake had the smallest age‐0 black crappie size and intermediate age‐0 fish abundance. Thus, we found no relationship between crustacean zooplankton density and black crappie size across lakes. Reduced Secchi depths due to high chlorophyll‐a values and wind resuspension of sediments may have reduced feeding efficiency for age‐0 black crappies at Lake Lochloosa relative to the other lakes. Age‐0 black crappie abundance and size during fall were not predicted solely by food availability, stock abundance, or water clarity, suggesting that these factors interacted to influence recruitment through the first year of life.

Composition, size, and biomass of zooplankton in large productive Florida lakes

“…This pattern has been observed in other Florida lakes with intense springtime fish predation (Tugend & Allen, 2000), and it is a pattern that Jeppesen et al (2007) attributed to the impacts of rapid grazing by opportunistic predators on an available resource. D. ambigua, the most vulnerable species of Cladocera to visual planktivores, is entirely absent in spring and summer in productive Florida lakes, when larval fish densities are maximal (Dockendorf & Allen, 2005). Overall, the results are supportive of the conclusion of Meerhoff et al (2007) that subtropical lakes have low biomass of macro-zooplankton because they contain aggressive planktivores.…”

Zooplankton response to extreme drought in a large subtropical lake

“…Predation also might explain, in part, the seasonal dynamics of cladocerans (Fig. 4), because the most sensitive species, D. ambigua, drops out of the community at the same time of year (spring-summer) when larval fish display their maximal densities in the water of eutrophic Florida lakes (Dockendorf & Allen, 2005). We also can draw inferences about intensity of fish predation by comparing ratios of zooplankton biomass to TP in Lake Okeechobee vs. other shallow lakes.…”

Consistently High Trophic Overlap between Invasive White Perch and Native Black Crappies in Southeastern Reservoirs

“…Black Crappies were also categorized as small (<115 mm TL), medium (115–200 mm TL), and large (≥200 mm TL). Small individuals comprised primarily age‐1 (in spring samples) or young‐of‐the‐year (summer and fall samples) individuals, whereas medium‐sized individuals comprised primarily juveniles (Dockendorf and Allen ; Jackson and Hurley ; Feiner et al. ), and large size‐classes contained older fish that had largely switched to piscivory.…”