Connectivity and Dispersal Patterns of Protected Biogenic Reefs: Implications for the Conservation of Modiolus modiolus (L.) in the Irish Sea

Kate Gormley; Clara Mackenzie; Peter Robins; Ilaria Coscia; Andrew Cassidy; Jenny James; Angela Hull; Stuart Piertney; William Sanderson; Joanne Porter

doi:10.1371/journal.pone.0143337

Connectivity and Dispersal Patterns of Protected Biogenic Reefs: Implications for the Conservation of Modiolus modiolus (L.) in the Irish Sea

PLoS One. 2015 Dec 1;10(12):e0143337. doi: 10.1371/journal.pone.0143337. eCollection 2015.

Authors

Affiliations

¹ School of Life Sciences, Heriot-Watt University, Riccarton, Edinburgh, EH14 4AS.
² School of Ocean Sciences, Bangor University, Menai Bridge, LL59 5AB.
³ Laboratory of Biodiversity and Evolutionary Genomics, University of Leuven, Ch. Deberiotstraat, 32, 3000 Leuven, Belgium.
⁴ Medical Research Institute, University of Dundee, Human Genetics Unit, Ninewells Hospital and Medical School, Dundee, DD1 9SY.
⁵ School of the Built Environment, Heriot-Watt University, Riccarton, Edinburgh, EH14 4AS.
⁶ The Institute of Biological and Environmental Sciences, Zoology Building, Tillydrone Avenue, Aberdeen, AB24 2TZ.

Abstract

Biogenic reefs created by Modiolus modiolus (Linnaeus, 1758) (horse mussel reefs) are marine habitats which support high levels of species biodiversity and provide valuable ecosystem services. Currently, M. modiolus reefs are listed as a threatened and/or declining species and habitat in all OSPAR regions and thus are highlighted as a conservation priority under the EU Marine Strategy Framework Directive (MSFD). Determining patterns of larval dispersal and genetic connectivity of remaining horse mussel populations can inform management efforts and is a critical component of effective marine spatial planning (MSP). Larval dispersal patterns and genetic structure were determined for several M. modiolus bed populations in the Irish Sea including those in Wales (North Pen Llŷn), Isle of Man (Point of Ayre) and Northern Ireland (Ards Peninsula and Strangford Lough). Simulations of larval dispersal suggested extant connectivity between populations within the Irish Sea. Results from the genetic analysis carried out using newly developed microsatellite DNA markers were consistent with those of the biophysical model. Results indicated moderately significant differentiation between the Northern Ireland populations and those in the Isle of Man and Wales. Simulations of larval dispersal over a 30 day pelagic larval duration (PLD) suggest that connectivity over a spatial scale of 150km is possible between some source and sink populations. However, it appears unlikely that larvae from Northern Ireland will connect directly with sites on the Llŷn or Isle of Man. It also appears unlikely that larvae from the Llŷn connect directly to any of the other sites. Taken together the data establishes a baseline for underpinning management and conservation of these important and threatened marine habitats in the southern part of the known range.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animal Distribution*
Animals
Conservation of Natural Resources*
Coral Reefs*
Ecosystem
Endangered Species
Larva
Microsatellite Repeats / genetics
Models, Statistical
Mytilidae* / genetics
Oceans and Seas*
Polymorphism, Genetic
Spatial Analysis

Grants and funding

This project was a PhD Scholarship funded by Heriot-Watt University. Partial funding was supplied by a Marine Alliance for Science and Technology for Scotland (MASTS) small grant fund ref: HR09011. Northern Ireland Environmental Agency, Natural Resources Wales and Isle of Man Government (Fiona Gell) also provided some additional funding for sample collection. The funders had no role in study design, data analysis, decision to publish, or preparation of the manuscript.