Connectivity modelling informs metapopulation structure and conservation priorities for a reef‐building species

Type Article
Date 2022-10
Language English
Author(s) David Carmen1, 2, Marzloff MartinORCID1, Knights Antony M.ORCID3, Cugier Philippe1, Nunes FlaviaORCID1, Cordier Celine1, Firth Louise B.ORCID3, Dubois StanislasORCID1, David
Affiliation(s) 1 : IFREMER, DYNECO Plouzané ,France
2 : Marine Animal Ecology Wageningen University and Research Wageningen ,The Netherlands
3 : School of Biological and Marine Sciences University of Plymouth Plymouth ,UK
Source Diversity And Distributions (1366-9516) (Wiley), 2022-10 , Vol. 28 , N. 10 , P. 2056-2070
DOI 10.1111/ddi.13596
Keyword(s) betweenness centrality, graph theory, habitat fragmentation, hydrodynamic modelling, larval dispersal, network analysis, resilience
Abstract

Aim

In coastal marine systems, biogenic reef-building species have great importance for conservation as they provide habitat for a wide range of species, promoting biodiversity, ecosystem functioning and services. Biogenic reef persistence and recovery from perturbations depend on recolonization by new recruits. Characterizing larval dispersal among distant reefs is key to understanding how connectivity shapes metapopulation structure and determines network coherence; all of which are of critical importance for effective conservation.

Location

Northeast Atlantic coast and western English Channel, France.

Methods

We used a biophysical transport model to simulate larval dispersal of the reef-building polychaete Sabellaria alveolata. We combined dispersal modelling and network analysis into a framework aiming to identify key reef areas and critical dispersal pathways, whose presence in the network is vital to its overall coherence. We evaluated changes in dispersal pathways constrained by different connectivity thresholds, i.e., minimum dispersal rate for the presence of a connection. We tested scenarios of sequential loss of reefs: randomly, by habitat quality (a score for reef status and occupancy in an area) or by betweenness centrality metric (BC; quantifying the proportion of shortest paths connecting all areas that are passing through any given area).

Results

We found that the network of S. alveolata reefs forms two main regional clusters, the Atlantic coast and the English Channel, which are connected only through weak sporadic dispersal events. Within each cluster, the network is characterized by relatively high connectivity among neighbouring areas with reefs, maintained even under higher connectivity thresholds. Simulating scenarios of sequential loss of reefs further identified high centrality reefs, those with highest BC values, key to network coherence.

Main conclusions

Effective conservation of this important reef habitat requires a network of protected areas designed to sustain a combination of locally important source reefs, and those that act as stepping stones connecting distant reefs.

Full Text
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Publisher's official version 15 4 MB Open access
Appendix S1 5 472 KB Open access
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How to cite 

David Carmen, Marzloff Martin, Knights Antony M., Cugier Philippe, Nunes Flavia, Cordier Celine, Firth Louise B., Dubois Stanislas, David (2022). Connectivity modelling informs metapopulation structure and conservation priorities for a reef‐building species. Diversity And Distributions, 28(10), 2056-2070. Publisher's official version : https://doi.org/10.1111/ddi.13596 , Open Access version : https://archimer.ifremer.fr/doc/00788/89949/