title: High dispersal potential has maintained long-term population stability in the North Atlantic copepod Calanus finmarchicus.
abstract: The cool-water copepod Calanus finmarchicus is a key species in North Atlantic marine ecosystems since it represents an important food resource for the developmental stages of several fish of major economic value. Over the last 40 years, however, data from the Continuous Plankton Recorder survey have highlighted a 70 per cent reduction in C. finmarchicus biomass, coupled with a gradual northward shift in the species's distribution, which have both been linked with climate change. To determine the potential for C. finmarchicus to track changes in habitat availability and maintain stable effective population sizes, we have assessed levels of gene flow and dispersal in current populations, as well as using a coalescent approach together with palaeodistribution modelling to elucidate the historical population demography of the species over previous changes in Earth's climate. Our findings indicate high levels of dispersal and a constant effective population size over the period 359,000-566,000 BP and suggest that C. finmarchicus possesses the capacity to track changes in available habitat, a feature that may be of crucial importance to the species's ability to cope with the current period of global climate change.
authors.affiliation: School of Biological Sciences, The Queen's University of Belfast, 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland. J.Provan@qub.ac.uk
authors.forename: Jim
authors.initials: J
authors.lastname: Provan
authors.forename: Gemma E
authors.initials: GE
authors.lastname: Beatty
authors.forename: Sianan L
authors.initials: SL
authors.lastname: Keating
authors.forename: Christine A
authors.initials: CA
authors.lastname: Maggs
authors.forename: Graham
authors.initials: G
authors.lastname: Savidge
mesh_terms: D025041:Animal Migration; D000818:Animals; D001267:Atlantic Ocean; D018533:Biomass; D033342:Copepoda / Q000235:genetics / Q000502:physiology*; D017753:Ecosystem; D053476:Extinction, Biological; D051456:Gene Flow; D005838:Genotype; D017752:Greenhouse Effect; D018895:Microsatellite Repeats; D011110:Polymorphism, Genetic; D011156:Population Density; D011157:Population Dynamics