Mercury bioaccumulation in bats reflects dietary connectivity to aquatic food webs

DJB was funded by a National Science Foundation Graduate Research Fellowship, an ARCS Foundation Award, Sigma Xi, the Odum School of Ecology, the University of Georgia Graduate School, the Explorer's Club, and the University of Georgia Biomedical and Health Sciences Institute. MMC and JMK were supported by a Texas Christian University Research and Creative Activities Fund Award, and HGB was supported by a Natural Sciences and Engineering Research Council of Canada Discovery Grant. TRR was supported by the Yawkey Foundation and Clemson University, and this paper represents Technical Contribution No. 6533 of the Clemson University Experiment Station. SGP was supported by the Wildlife Conservation Society, and NBS was supported by the American Museum of Natural History Taxonomic Mammalogy Fund

Biomass-dependent Effects of Age-0 Common Carp on Aquatic Ecosystems

Fishes play a functional role in structuring aquatic ecosystems through top-down and bottom-up processes. Adult common carp (Cyprinus carpio) are well recognized for their middle-out effects on aquatic ecosystems that can shift shallow lakes from the clear- to turbid-water stable state through benthic foraging activities. However, less is known about ecosystem effects of age-0 common carp. Age-0 common carp are planktivorous and can be highly abundant, suggesting that large year classes may also produce undesirable ecosystem effects. We evaluated the effects of four age-0 common carp densities (0, 175, 475, and 812 kg/ha) on water quality (ammonium, total phosphorus, total Kjeldahl nitrogen, and turbidity) and primary (macrophytes and phytoplankton) and secondary (zooplankton and benthic invertebrates) production. Common carp increased nutrient availability and phytoplankton production and decreased water transparency with effects increasing with carp biomass. Common carp also reduced macrophyte coverage and cladocera density (through effects on chydorus and ceriodaphnia) and body size, but effects were not density dependent. In contrast, common carp did not appear to affect copepod, rotifer, chironomid, or gastropod densities. These results suggest that even relatively low age-0 common carp densities (\u3e175 kg/ha) may have many comparable ecosystem effects as adult carp, although effects may be accrued through different pathways