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

Research output: Contribution to journalArticle


Gene flow in macroalgal populations can be strongly influenced by spore or gamete dispersal. This, in turn, is influenced by a convolution of the effects of current flow and specific plant reproductive strategies. Although several studies have demonstrated genetic variability in macroalgal populations over a wide range of spatial scales, the associated current data have generally been poorly resolved spatially and temporally. In this study, we used a combination of population genetic analyses and high-resolution hydrodynamic modelling to investigate potential connectivity between populations of the kelp Laminaria digitata in the Strangford Narrows, a narrow channel characterized by strong currents linking the large semi-enclosed sea lough, Strangford Lough, to the Irish Sea. Levels of genetic structuring based on six microsatellite markerswere very low, indicating high levels of gene flowand a pattern of isolation-by-distance, where populations are more likely to exchange migrants with geographically proximal populations, but with occasional long-distance dispersal. This was confirmed by the particle tracking model, which showed that, while the majority of spores settle near the release site, there is potential for dispersal over several kilometres. This combined population genetic and modelling approach suggests that the complex hydrodynamic environment at the entrance to Strangford Lough can facilitate dispersal on a scale exceeding that proposed for L. digitata in particular, and the majority of macroalgae in general. The study demonstrates the potential of integrated physical-biological approaches for the prediction of ecological changes resulting from factors such as anthropogenically induced coastal zone changes.


  • Georgina Brennan
  • Louise Kregting
  • Gemma E. Beatty
  • Claudia Cole
  • Björn Elsäßer
  • Graham Savidge
  • Jim Provan
External organisations
  • Queen's University Belfast
Research areas and keywords


  • Dispersal, Hydrology, Laminaria digitata, Macroalgae, Particle tracking modelling, Population genetics
Original languageEnglish
Article number20140197
Number of pages12
JournalJournal of the Royal Society Interface
Issue number95
Publication statusPublished - 2014 Jun 6
Publication categoryResearch
Externally publishedYes