BRAUNS (M.), GARCIA (X.F.), WALZ (N), PUSCH (M.) 2007.- Effects of human shoreline development on littoral macroinvertebrates in lowland lakes. Journal of Applied Ecology, 44(6): 1138-1144.
1. The shores of many lakes have been substantially altered by human developments such as erosion control structures or recreational beaches. Such alterations are likely to increase in the future, yet almost nothing is known about their impacts on the littoral macroinvertebrate community.
2. Macroinvertebrates were studied at seven German lowland lakes exhibiting natural shorelines (reference), retaining walls, ripraps and recreational beaches to examine impacts on eulittoral (0 - 0.2 m water depth) and infralittoral (0.2 - 1.2 m water depth) communities associated with the three types of shoreline development.
3. Among sites, eulittoral species richness and abundance of Coleoptera, Gastropoda, Trichoptera, shredders and xylophagous species were lowest at beaches and retaining walls, but ripraps did not differ significantly from natural shorelines. Retaining walls and ripraps had no significant impact on the infralittoral macroinvertebrate community. Conversely, beaches had significantly lower infralittoral species richness and lower abundance of Bivalvia, Crustacea, Ephemeroptera, Trichoptera and shredders than natural shorelines. Furthermore, species richness was positively correlated with habitat heterogeneity expressed as number of habitat types.
4. Among lakes, whole-lake littoral macroinvertebrate density increased with increasing proportion of developed shorelines due to increasing abundances of Chironomidae. The remaining macroinvertebrate major groups decreased with increasing proportion of shoreline development.
5. Synthesis and application
The biological impacts of shoreline development in lowland lakes depend on the extent to which structural complexity and heterogeneity of littoral habitats are reduced. Hence, we recommend that management programs focus on the conservation of littoral habitat complexity and habitat heterogeneity. Biological effects of shoreline development may be efficiently assessed by combining an assessment of the morphological status of lakeshores and information on macroinvertebrate indicator species with a defined response to the loss of their preferred habitats.