Effect of Wetland Enhancement on Parasites of Juvenile Yellow Perch

Abstract

Impoundments and dams are frequently used in wetlands to stabilize water levels and maintain breeding habitat for waterfowl. The objective of the study was to examine the effect of reduced water level fluctuations and connectivity on fish parasitism in wetlands caused by the installation of such structures. We compared parasites of juvenile yellow perch (Perca flavescens) from two enhanced wetlands where water level is regulated and where connection with the main channel occurs only during spring flood (enhanced wetlands) to parasites of juvenile perch living in seasonally flooded wetlands where connection with the main channel is continuous (natural wetlands). Parasite species richness and Shannon diversity index were higher in natural than in enhanced wetlands. Jaccard similarity index revealed a higher similarity in parasite assemblages within than between each type of wetlands. Glochidia and parasites that include clams in their life cycle were absent from the two enhanced wetlands. Our study suggested that local factors such as water level fluctuation and connectivity in enhanced wetlands may limit the establishment of bivalves and that the use of impoundments and dams in wetlands areas may have an impact on some components of the food web.

Estimating the feeding range of a mobile consumer in a river-flood plain system using δ13C gradients and parasites

“…These observations therefore support our assumption that fish collected at spawning sites were representative of the whole population, which dispersed in the lake postspawning. Seven sites where primary consumers were collected were situated in the spring high‐water areas where water then completely receded after a period of c. 1 month (Bertrand, Marcogliese & Magnan 2010). We excluded these sites from our calculations of feeding ranges of perch because their contribution to total fish carbon over the whole year is likely to be minimal.…”