Publications (37) View all
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Dataset: Halpern etal 2008 Science SOM
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Article: Development and inheritance of molecular markers in the kelp bass Paralabrax clathratus
Fisheries Science 04/2012; 75(2):525-527. · 0.94 Impact Factor -
Article: The structure of Mediterranean rocky reef ecosystems across environmental and human gradients, and conservation implications
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ABSTRACT: Historical exploitation of the Mediterranean Sea and the absence of rigorous baselines makes it difficult to evaluate the current health of the marine ecosystems and the efficacy of conservation actions at the ecosystem level. Here we establish the first current baseline and gradient of ecosystem structure of nearshore rocky reefs at the Mediterranean scale. We conducted underwater surveys in 14 marine protected areas and 18 open access sites across the Mediterranean, and across a 31-fold range of fish biomass (from 3.8 to 118 g m(-2)). Our data showed remarkable variation in the structure of rocky reef ecosystems. Multivariate analysis showed three alternative community states: (1) large fish biomass and reefs dominated by non-canopy algae, (2) lower fish biomass but abundant native algal canopies and suspension feeders, and (3) low fish biomass and extensive barrens, with areas covered by turf algae. Our results suggest that the healthiest shallow rocky reef ecosystems in the Mediterranean have both large fish and algal biomass. Protection level and primary production were the only variables significantly correlated to community biomass structure. Fish biomass was significantly larger in well-enforced no-take marine reserves, but there were no significant differences between multi-use marine protected areas (which allow some fishing) and open access areas at the regional scale. The gradients reported here represent a trajectory of degradation that can be used to assess the health of any similar habitat in the Mediterranean, and to evaluate the efficacy of marine protected areas.PLoS ONE 02/2012; 7(2):e32742. · 4.09 Impact Factor -
Chapter: Eliciting Expert Knowledge of Ecosystem Vulnerability to Human Stressors to Support Comprehensive Ocean Management
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ABSTRACT: More than 38% of the world’s population lives within 100 km of the coast, and the coastal zone is becoming more heavily populated each year (Small and Cohen 2004). More and more human activities depend upon and compete for coastal and marine ecosystem goods and services. This intensification of use is necessitating a shift toward more comprehensive and integrated approaches to management – a shift that is already underway via approaches such as ecosystem-based management and ocean zoning (Day 2002; McLeod et al. 2005; Crowder et al. 2006; Douvere et al. 2007; Douvere 2008; Office of the President 2010). Given the diversity of human uses and natural resources that converge in coastal waters, understanding the potential independent and cumulative impacts of those uses and associated stressors on marine ecosystems can be very challenging. Little empirical data is available to weigh the relative vulnerability of the range of ecosystem types to the full set of human stressors (Halpern et al.10/2011: pages 253-277; -
Article: Taking the chaos out of genetic patchiness: seascape genetics reveals ecological and oceanographic drivers of genetic patterns in three temperate reef species.
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ABSTRACT: Marine species frequently show weak and/or complex genetic structuring that is commonly dismissed as 'chaotic' genetic patchiness and ecologically uninformative. Here, using three datasets that individually feature weak chaotic patchiness, we demonstrate that combining inferences across species and incorporating environmental data can greatly improve the predictive value of marine population genetics studies on small spatial scales. Significant correlations in genetic patterns of microsatellite markers among three species, kelp bass Paralabrax clathratus, Kellet's whelk Kelletia kelletii and California spiny lobster Panulirus interruptus, in the Southern California Bight suggest that slight differences in diversity and pairwise differentiation across sampling sites are not simply noise or chaotic patchiness, but are ecologically meaningful. To test whether interspecies correlations potentially result from shared environmental drivers of genetic patterns, we assembled data on kelp bed size, sea surface temperature and estimates of site-to-site migration probability derived from a high resolution multi-year ocean circulation model. These data served as predictor variables in linear models of genetic diversity and linear mixed models of genetic differentiation that were assessed with information-theoretic model selection. Kelp was the most informative predictor of genetics for all three species, but ocean circulation also played a minor role for kelp bass. The shared patterns suggest a single spatial marine management strategy may effectively protect genetic diversity of multiple species. This study demonstrates the power of environmental and ecological data to shed light on weak genetic patterns and highlights the need for future focus on a mechanistic understanding of the links between oceanography, ecology and genetic structure.Molecular Ecology 09/2010; 19(17):3708-26. · 5.52 Impact Factor
