Author: Ridouan BaniPublisher:
ISBN:
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Languages : en
Pages :
Book Description
"Conservation of coastal ecosystems, from the prediction of their response to climate change, to the design of effective marine reserve networks, requires that we understand the role of complex oceanic transport patterns as a major driver of connectivity among marine populations that disperse though a pelagic larval phase. Metapopulation theories have provided many insights on the role of dispersal for population persistence and stability, but few studies have integrated spatiotemporal variability in ocean currents and connectivity. In marine systems, the fate of propagules (egg or larvae) depends on ocean currents and on biological traits associated with dispersal such as spawning time and pelagic larval duration, which in turn can be affected by changing environmental conditions such as temperature. My thesis introduces a new theory of marine metapopulations under fluctuating connectivity and makes it applicable to predicting metapopulation response to climate change and to the design of marine reserve networks. I first develop a new theory that explains how spatiotemporal patterns of larval dispersal affect marine metapopulation growth and stability (Chapter 2). I then study the different pathways throughout which climate change is expected to affect metapopulation stability, by considering its effects on both biological traits associated with dispersal and on ocean currents (Chapter 3). I finally extended current reserve network theories and derived the contributions of both within- and between-reserve fluctuations in connectivity to the stability of whole MPA networks in relation to MPA size and spacing. I explain how spatiotemporal patterns of larval dispersal can create nested network within individual MPAs with important impacts on MPA network persistence. The three chapters combine theoretical approaches with application to specific case study (Northeast Pacific coastal system). The dynamic connectivity theory contained in this thesis captures the temporal as well as the spatial variation of larval dispersal between habitats, and helped reveal the complex relationship between pelagic traits (pelagic larval duration and spawning time), the statistical moments of dynamic connectivity. and metapopulation growth and stability. These complex relationships, once resolved, can explain non-monotonic and counterintuitive relationship between larval duration and climate change effects on marine metapopulations. Applying dynamic connectivity theory to the design of marine reserve networks shows how within-reserve connectivity can be as important as between-reserve connectivity for optimizing reserve size and spacing"--
