TY - JOUR

T1 - Understanding macroalgal dispersal in a complex hydrodynamic environment: a combined population genetic and physical modelling approach

AU - Brennan, Georgina

AU - Kregting, Louise

AU - Beatty, Gemma

AU - Cole , Claudia

AU - Elsäßer, Björn

AU - Savidge, Graham

AU - Provan, Jim

PY - 2014/3/26

Y1 - 2014/3/26

N2 - Gene flow in macroalgal populations can be strongly influenced by spore orgamete dispersal. This, in turn, is influenced by a convolution of the effectsof current flow and specific plant reproductive strategies. Although severalstudies have demonstrated genetic variability in macroalgal populationsover a wide range of spatial scales, the associated current data have generallybeen poorly resolved spatially and temporally. In this study, we used a combination of population genetic analyses and high-resolution hydrodynamicmodelling to investigate potential connectivity between populations of thekelp Laminaria digitata in the Strangford Narrows, a narrow channel characterizedby strong currents linking the large semi-enclosed sea lough, StrangfordLough, to the Irish Sea. Levels of genetic structuring based on six microsatellitemarkers were very low, indicating high levels of gene flow and a pattern of isolation-by-distance, where populations are more likely to exchange migrantswith geographically proximal populations, but with occasional long-distancedispersal. This was confirmed by the particle tracking model, which showedthat, while the majority of spores settle near the release site, there is potentialfor dispersal over several kilometres. This combined population genetic andmodelling approach suggests that the complex hydrodynamic environmentat the entrance to Strangford Lough can facilitate dispersal on a scale exceedingthat proposed for L. digitata in particular, and the majority of macroalgaein general. The study demonstrates the potential of integrated physical–biological approaches for the prediction of ecological changes resulting fromfactors such as anthropogenically induced coastal zone changes.

AB - Gene flow in macroalgal populations can be strongly influenced by spore orgamete dispersal. This, in turn, is influenced by a convolution of the effectsof current flow and specific plant reproductive strategies. Although severalstudies have demonstrated genetic variability in macroalgal populationsover a wide range of spatial scales, the associated current data have generallybeen poorly resolved spatially and temporally. In this study, we used a combination of population genetic analyses and high-resolution hydrodynamicmodelling to investigate potential connectivity between populations of thekelp Laminaria digitata in the Strangford Narrows, a narrow channel characterizedby strong currents linking the large semi-enclosed sea lough, StrangfordLough, to the Irish Sea. Levels of genetic structuring based on six microsatellitemarkers were very low, indicating high levels of gene flow and a pattern of isolation-by-distance, where populations are more likely to exchange migrantswith geographically proximal populations, but with occasional long-distancedispersal. This was confirmed by the particle tracking model, which showedthat, while the majority of spores settle near the release site, there is potentialfor dispersal over several kilometres. This combined population genetic andmodelling approach suggests that the complex hydrodynamic environmentat the entrance to Strangford Lough can facilitate dispersal on a scale exceedingthat proposed for L. digitata in particular, and the majority of macroalgaein general. The study demonstrates the potential of integrated physical–biological approaches for the prediction of ecological changes resulting fromfactors such as anthropogenically induced coastal zone changes.

KW - dispersal, macroalgae, population genetics, particle tracking modelling, Laminaria digitata, hydrology

U2 - 10.1098/rsif.2014.0197

DO - 10.1098/rsif.2014.0197

M3 - Article

VL - 11

SP - 1

JO - Journal of the Royal Society, Interface

JF - Journal of the Royal Society, Interface

SN - 1742-5689

IS - 95

ER -