Author: Rachel M Fricke,  Student (University of Washington)

Description:
Declines in freshwater biodiversity across the globe are well-documented. At the same time, an increasing number of waterbodies are subjected to multiple human demands. Yet, assessments of the influence of waterbody management practices on biodiversity remain rare and often focus on a few organism groups at a limited spatial scale or examine only select indicator taxa. In Lower Saxony, Germany, small gravel-pit lakes (< 20 ha) created by mining comprise most of the region’s freshwater resources. Most of these lakes are managed by local angling communities, which involves regular fish stocking and increased human use. Some similarly aged gravel-pit lakes are not managed by recreational fisheries, serving as whole-ecosystem replicates to study the systematic impact of fisheries management on biodiversity. We investigated multiple aquatic and riparian organism groups (waterfowl, songbirds, amphibians, dragonflies, damselflies, submerged macrophytes, and riparian vegetation) in 37 managed and unmanaged lakes and assessed the influence of environmental conditions (local and regional), fish density, human use, and fisheries management on community composition. With the exception of amphibians, we find recreational-angling management has negligible impacts on aquatic and riparian communities. Instead, community composition is mainly affected by non-angling related environmental and landscape-scale factors. Thus, we conclude recreational-fisheries management is not a major constraint for the development of biodiversity-rich aquatic and riparian communities at gravel-pit lakes.

Category: Scientific Program Abstract > Special Session > CS02 Management and Conservation of Aquatic Systems