First come, first served: Possible role for priority effects in marine populations under different degrees of dispersal potential

Journal of Biogeography, vol. 47, pp. 1649–1662

Abstract

Abstract Aim Studying clearly delineated populations in marine lakes, islands of sea, we investigated the interplay of habitat size, dispersal potential, and priority effects in shaping marine population genetic structure. Location Marine lakes and coastal locations in Indonesia, Palau, Papua New Guinea and Australia. Taxon Mussels (Mytilidae, Brachidontes spp.) Methods Populations were sampled from four coastal locations and 22 marine lakes of similar age (~8,000 years), yet differing in size (0.04–4.7 km2) and degree of connection to the adjacent sea. While some lakes are highly connected, allowing potential influx of larvae from the sea, others have very limited water exchange. We assessed the phylogeographical structure and demographic history using mitochondrial and nuclear DNA sequence data, and combined this with geometric morphometrics. The effects of lake characteristics on population genetic diversity and structure were tested using linear regression and Mantel tests. Results Each lake contained one of six distinct genetic lineages, which were characterized by deep phylogenetic splits and significant morphometric differences. These lineages likely represent separate species. The lineages showed similar demographic patterns, with lakes containing founder populations that rapidly expanded and diverged. Genetic diversity within lake populations was significantly correlated with lake area, but not with physical connection to the adjacent sea. Within lineages that occurred in multiple lakes there was strong population structure (average ΦST 0.65), which did not conform to an isolation‐by‐distance pattern or to the degree of dispersal potential. Main Conclusions Marine lakes across a gradient of physical isolation show strong population structure and evidence for in situ divergence. We hypothesize that the observed genetic structure is the result of priority effects. In addition, reduction of habitat size appears to reduce genetic diversity, even at very small spatial scales. Our findings are relevant in the context of ongoing alterations to coastal hydrodynamics, which lead to habitat reduction and influence migration among populations at fine spatial scales.

Authors 9

1. Christiaan A. de Leeuw corresponding

   Wageningen University & Research

   Affiliation as printed

   Wageningen University & Research Wageningen The Netherlands

2. Katja T. C. A. Peijnenburg Aachen Naturalis Biodiversity Center Leiden The Netherlands Naturalis Biodiversity Center

   Naturalis Biodiversity Center · University of Amsterdam

   Affiliation as printed

   Institute for Biodiversity and Ecosystem Dynamics (IBED) University of Amsterdam Amsterdam The Netherlands

   Naturalis Biodiversity Center Leiden The Netherlands

   Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Amsterdam, The Netherlands

   Naturalis Biodiversity Center, Leiden, The Netherlands

3. Rosemary Grace Gillespie

   University of California, Berkeley

   Affiliation as printed

   Department of Environmental Science, Policy, and Management University of California Berkeley CA USA

   Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, USA

4. Diede Louise Maas

   Wageningen University & Research

   Affiliation as printed

   Wageningen University & Research Wageningen The Netherlands

5. Naoto Hanzawa

   Yamagata University

   Affiliation as printed

   Faculty of Science Yamagata University Yamagata Japan

   Faculty of Science, Yamagata University, Yamagata, Japan

6. Yosephine Tuti

   Indonesian Institute of Sciences

   Affiliation as printed

   Indonesian Institute of Sciences Research Centre for Oceanography Jakarta Indonesia

   Indonesian Institute of Sciences, Research Centre for Oceanography, Jakarta, Indonesia

7. Abdul Hamid A. Toha

   Universitas Papua

   Affiliation as printed

   Department of Fisheries Faculty of Fisheries and Marine Sciences University of Papua Indonesia

   Department of Fisheries, Faculty of Fisheries and Marine Sciences, University of Papua, Indonesia

8. Ludi Parwadani Aji

   Indonesian Institute of Sciences · Wageningen University & Research

   Affiliation as printed

   Indonesian Institute of Sciences Research Centre for Oceanography Jakarta Indonesia

   Wageningen University & Research Wageningen The Netherlands

   Indonesian Institute of Sciences, Research Centre for Oceanography, Jakarta, Indonesia

9. Leontine Elisabeth Becking corresponding Aachen Naturalis Biodiversity Center Leiden The Netherlands Naturalis Biodiversity Center

   Naturalis Biodiversity Center · Wageningen University & Research · University of California, Berkeley

   Affiliation as printed

   Department of Environmental Science, Policy, and Management University of California Berkeley CA USA

   Naturalis Biodiversity Center Leiden The Netherlands

   Wageningen University & Research Wageningen The Netherlands

   Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, USA

   Naturalis Biodiversity Center, Leiden, The Netherlands