Publication Date:
2016-06-03
Description:
Biological invasions are projected to be the main driver of biodiversity and ecosystem function loss in lakes in the 21 st century. However, the extent of these future losses is difficult to quantify because most invasions are recent and confounded by other stressors. In this study we quantified the outcome of a century-old invasion, the introduction of common carp to North America, to illustrate potential consequences of introducing non-native ecosystem engineers to lakes worldwide. We used the decline in aquatic plant richness and cover as an index of ecological impact across three ecoregions: Great Plains, Eastern Temperate Forests, Northern Forests. Using whole lake manipulations, we demonstrated that both submersed plant cover and richness declined exponentially as carp biomass increased such that plant cover was reduced to less than 10% and species richness was halved in lakes in which carp biomass exceeded 190 kg/ha. Using catch rates amassed from 2,000+ lakes we showed that carp exceeded this biomass level in 70.6% of Great Plains lakes, 23.3% of EasternTemperate Forests lakes, but 0% of Northern Forests lakes. Using model selection analysis we showed that carp was a key driver of plant species richness along with Secchi depth, lake area and human development of lake watersheds. Model parameters showed that carp reduced species richness to a similar degree across lakes of various Secchi depths and areas. In regions dominated by carp (e.g. Great Plains), carp had a stronger impact on plant richness than human watershed development. Overall, our analysis shows that the introduction of common carp played a key role in driving a severe reduction in plant cover and richness in majority of Great Plains lakes and a large portion of Eastern Temperate Forests lakes in North America. This article is protected by copyright. All rights reserved.
Print ISSN:
1354-1013
Electronic ISSN:
1365-2486
Topics:
Biology
,
Energy, Environment Protection, Nuclear Power Engineering
,
Geography
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