Comparison of Marine Spatial Planning Methods in Madagascar Demonstrates Value of Alternative Approaches

et al. (2012) Comparison of Marine Spatial Planning Methods in Madagascar Demonstrates Value of Alternative Approaches. PLoS ONE 7(2): e28969. doi:10.1371/journal.pone.0028969 Comparison of Marine Spatial Planning Methods in Madagascar Demonstrates Value of Alternative Approaches Thomas F. Allnutt 0 Timothy R. McClanahan 0 Serge Andre foue t 0 Merrill Baker 0 Erwann Lagabrielle 0 Caleb McClennen 0 Andry J. M. Rakotomanjaka 0 Tantely F. Tianarisoa 0 Reg Watson 0 Claire Kremen 0 Richard K. F. Unsworth, Swansea University, United Kingdom 0 1 Department of Environmental Science , Policy and Management , University of California, Berkeley, Berkeley, California, United States of America, 2 Marine Programs, Wildlife Conservation Society, Bronx, New York, United States of America, 3 Institut de Recherche pour le De veloppement, Noume a Cedex, New Caledonia, 4 Institut de Recherche pour le De veloppement, Sainte-Clotilde, France, 5 Botany Department, Nelson Mandela Metropolitan University , George, South Africa, 6 Madagascar Program, Wildlife Conservation Society, Antananarivo, Madagascar, 7 Fisheries Center , University of British Columbia , Vancouver , Canada The Government of Madagascar plans to increase marine protected area coverage by over one million hectares. To assist this process, we compare four methods for marine spatial planning of Madagascar's west coast. Input data for each method was drawn from the same variables: fishing pressure, exposure to climate change, and biodiversity (habitats, species distributions, biological richness, and biodiversity value). The first method compares visual color classifications of primary variables, the second uses binary combinations of these variables to produce a categorical classification of management actions, the third is a target-based optimization using Marxan, and the fourth is conservation ranking with Zonation. We present results from each method, and compare the latter three approaches for spatial coverage, biodiversity representation, fishing cost and persistence probability. All results included large areas in the north, central, and southern parts of western Madagascar. Achieving 30% representation targets with Marxan required twice the fish catch loss than the categorical method. The categorical classification and Zonation do not consider targets for conservation features. However, when we reduced Marxan targets to 16.3%, matching the representation level of the ''strict protection'' class of the categorical result, the methods show similar catch losses. The management category portfolio has complete coverage, and presents several management recommendations including strict protection. Zonation produces rapid conservation rankings across large, diverse datasets. Marxan is useful for identifying strict protected areas that meet representation targets, and minimize exposure probabilities for conservation features at low economic cost. We show that methods based on Zonation and a simple combination of variables can produce results comparable to Marxan for species representation and catch losses, demonstrating the value of comparing alternative approaches during initial stages of the planning process. Choosing an appropriate approach ultimately depends on scientific and political factors including representation targets, likelihood of adoption, and persistence goals. - Funding: This work was supported by MacArthur Foundation grants 07-89636-000-GSS and 07-89630-001-GSS. The fish catch model was developed from the Sea Around Us global catch database This database was developed through a scientific collaboration between the University of British Columbia and the Pew Environment Group. The Indian Ocean Commission, Fond Francais pour lEnvironnement Mondial and World Wildlife Fund funded the Indian Ocean Commission Protected Areas Network conservation planning workshop. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist. While climate change, overfishing and land use change negatively impact the biodiversity and ecological function of marine ecosystems worldwide [1,2], increasing evidence shows that effective conservation and management can recover the resource base, conserve biodiversity, and increase fishers incomes [3,4,5,6,7]. Yet targeting interventions to maximize returns across large regions remains a major challenge: in most tropical seas, for example, basic patterns and interactions among key biological, environmental and social variables remain poorly understood [8]. In addition, while appropriate targeting methods and data sources may exist, they can be underutilized due to a lack of real-world examples and comparative evaluations [9]. In this paper we compare four alternative methods of successive technical complexity for identifying conservation and management priorities across Madagascars west coast, a regionally and globally important tropical coral reef ecosystem [10,11]. The waters of the West Coast of Madagascar are home to 90% of Madagascars coral reefs, large-scale export fisheries for shrimp, octopus, sea cucumbers, and tuna, and important artisanal fisheries. Nonetheless, the formal management of marine resources in the region is in its initial stages. There is only one fully decreed marine protected area (MPA) (Sahamalaza-Isles Radama), with several others in various stages of designation. Less than 1% of Madagascars reefs are included in no-take areas, the lowest rate for five West Indian Ocean countries [12]. Few additional areas are under formal marine management across a region spanning thousands of kilometers of coastline and home to nearly two million people, many of whom are dependent on marine resources as an important protein source for local consumption and as a source of cash from export or sale [13,14]. Due to inadequate marine resource management across the majority of the region, fishers target lower trophic levels [15], and the use of illegal and destructive gear such as small-meshed beach seine nets is widespread [16]. As a result, large areas of the regions coral reef ecosystems are chronically stressed [17]. Several governmental, non-governmental and community organizations in Madagascar are interested in increasing the scale of marine resource management on Madagascars west coast through MPAs and other strategies [18]. In general, increasing the scope and effectiveness of marine resource management across large areas requires a large-scale spatial synthesis of biological, socio-economic and environmental patterns [19]; such a synthesis is lacking across Madagascars west coast, since the region is large, relatively inaccessible and insufficiently surveyed [11]. Many methods now exist for mapping conservation priorities and management actions in marine systems. Collectively termed Marine Spatial Planning [20], this appro (...truncated)