Source–sink dynamics explain the distribution and persistence of an invasive population of common carp across a model Midwestern watershed
Source–sink theory is an ecological framework that describes how site and habitat-specific demographic rates and patch connectivity can explain population structure and persistence across heterogeneous landscapes. Although commonly used in conservation planning, source–sink theory has rarely been applied to the management of invasive species. This study tested whether the common carp, one of the world’s most invasive species, exhibits source–sink dynamics in a representative watershed in the Upper Mississippi River Basin comprised of a dozen interconnected ponds and lakes. To test for source–sink population structure, we used standard fish sampling techniques, tagging, and genetic assignment methods to describe habitat-specific recruitment rates and dispersal. Five years of sampling revealed that while adult carp were found across the entire watershed, reproductive success (the presence of young carp) was restricted to shallow ponds. Additionally, nearly a third of the carp tagged in a representative pond dispersed into the connected deeper lakes, suggesting that ponds in this system serve as sources and lakes as sinks. This possibility was confirmed by microsatellite analysis of carp tissue samples (n = 1041) which revealed the presence of two distinct strains of carp cohabitating in the lakes, whose natal origins could be traced back to one of two pond systems, with many adult carp attempting to migrate back into these natal ponds to spawn. We conclude that the distribution and persistence of invasive carp in complex interconnected systems may often be driven by source–sink dynamics and that their populations could be controlled by suppressing reproduction in source habitats or by disrupting dispersal pathways, instead of culling individuals from sink habitats.
KeywordsDemographics Microsatellite Homing Aquatic invasive species Habitat heterogeneity Watershed scale
This work was funded by the Ramsey-Washington Metro Watershed District (RWMWD). We thank Nathan Berg, Justin Howard, Jacob Osborne, Mary Headrick, Brett Miller, Seth Miller, and Danielle Grunzke for assistance with fieldwork and laboratory analyses. We would also like to thank RWMWD staff, specifically Bill Bartodziej and Simba Blood, for project coordination and support. We thank Jessica Eichmiller and three anonymous reviewers for their helpful comments.
- Bonneau JL, Scarnecchia DL (2002) Spawning-season homing of common carp and river carpsucker. Prairie Nat 32:13–20Google Scholar
- Boughton DA (1999) Empirical evidence for complex source–sink dynamics with alternative states in a butterfly metapopulation. Ecology 80:2727–2739Google Scholar
- Crowder LB, Lyman SJ, Figueira WF, Priddy J (2000) Source–sink population dynamics and the problem of siting marine reserves. Bull Mar Sci 66:799–820Google Scholar
- Hubert WA (1996) Passive capture techniques. In: Murphy BR, Willis DW (eds) Fisheries techniques, 2nd edn. American Fisheries Society, Maryland, pp 157–192Google Scholar
- Lowe S, Browne M, Boudjelas S, De Poorter M (2000) 100 of the world’s worst invasive alien species: a selection from the global invasive species database. Invasive Species Specialist Group, AucklandGoogle Scholar
- Osborne JB (2012) Distribution, abundance and overwinter survival of young-of-year common carp in a Midwestern watershed. MS thesis, University of Minnesota. https://conservancy.umn.edu/handle/11299/123056)
- Sorensen PW, Bajer PG (2011) The common carp. In: Simberloff D, Rejmanek M (eds) Encyclopedia of invasive introduced species. University of California Press, Berkely, pp 100–103Google Scholar