Red de reservas marinas para la Región de las Grandes Islas, Golfo de California: protocolo del proyecto de planeación y reporte de los talleres del equipo de planeación [Marine reserves network for the Midriff Islands Region, Gulf of California, Mexico: planning protocol and progress report to the WWF Mexico & Carlos Slim Foundation Alliance]

La Región de las Grandes Islas (RGI), localizada en el acuario del mundo, el Golfo de California, es reconocida a nivel mundial por su espectacular belleza, diversidad y productividad; en ocasiones se le ha denominada como "las Galápagos del Hemisferio Norte" (Figura 1). En sus 45 islas, incluyendo las dos más grandes de México, Tiburón e Isla Ángel de la Guarda, se han registrado más de 400 especies de plantas, anfibios, reptiles y mamíferos terrestres, algunas de ellas endémicas a una o varias de las islas. En algunas de estas islas, como Rasa y San Pedro Mártir, llegan a anidar cientos de miles de aves marinas. Alrededor de este gran archipiélago, se pueden observar hasta 23 especies de mamíferos marinos, incluyendo la súper agregación de cachalotes en la cuenca San Pedro Mártir. Así como también es un sitio usado por cinco especies de tortugas marinas para hibernar y alimentarse. [English] In collaboration with researchers, agencies and NGOs, we aim to guide the design and implementation of a network of marine reserves for Midriff Islands, Gulf of California, a marine conservation hotspot. The area is one of the most important fishing regions in Mexico and livelihoods of coastal communities are threatened by depletion of fish stocks and climate change. The project aims to develop a practical approach to design networks of marine reserves that consider ecological connectivity and the effects of climate change. The project is an example of interdisciplinary and collaborative applied research, including over 25 researchers and managers from NGOs (COBI, Pronatura), universities (James Cook University, The University of Queensland, Arizona State University, SCRIPPS, The University of Arizona), and national (Mexico’s Commissions for Protected Areas and Biodiversity) and international agencies (NOAA)

Designing connected marine reserves in the face of global warming

Marine reserves are widely used to protect species important for conservation and fisheries and to help maintain ecological processes that sustain their populations, including recruitment and dispersal. Achieving these goals requires well-connected networks of marine reserves that maximize larval connectivity, thus allowing exchanges between populations and recolonization after local disturbances. However, global warming can disrupt connectivity by shortening potential dispersal pathways through changes in larval physiology. These changes can compromise the performance of marine reserve networks, thus requiring adjusting their design to account for ocean warming. To date, empirical approaches to marine prioritization have not considered larval connectivity as affected by global warming. Here, we develop a framework for designing marine reserve networks that integrates graph theory and changes in larval connectivity due to potential reductions in planktonic larval duration (PLD) associated with ocean warming, given current socioeconomic constraints. Using the Gulf of California as case study, we assess the benefits and costs of adjusting networks to account for connectivity, with and without ocean warming. We compare reserve networks designed to achieve representation of species and ecosystems with networks designed to also maximize connectivity under current and future ocean-warming scenarios. Our results indicate that current larval connectivity could be reduced significantly under ocean warming because of shortened PLDs. Given the potential changes in connectivity, we show that our graph-theoretical approach based on centrality (eigenvector and distance-weighted fragmentation) of habitat patches can help design better-connected marine reserve networks for the future with equivalent costs. We found that maintaining dispersal connectivity incidentally through representation-only reserve design is unlikely, particularly in regions with strong asymmetric patterns of dispersal connectivity. Our results support previous studies suggesting that, given potential reductions in PLD due to ocean warming, future marine reserve networks would require more and/or larger reserves in closer proximity to maintain larval connectivity