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Yasue M.,Quest University Canada | Nellas A.,Project Seahorse Foundation for Marine Conservation | Panes H.,Project Seahorse Foundation for Marine Conservation | Vincent A.C.J.,University of British Columbia
Endangered Species Research

For many small-scale, tropical reef fisheries, landed catch may be the only data that can be monitored to assess the impacts of management. This is true for seahorses Hippocampus comes that are obtained as part of a multi-species fishery in the Philippines. Here, because seahorses are locally rare and depleted, it is difficult to attain large enough sample sizes to detect changes over time using underwater surveys. We assessed changes in seahorse sales at 2 sites, from 1996 and 2005 respectively to 2010. The study period covered local and national conservation initiatives that could affect seahorses and dependent fisheries: establishment of marine reserves (1998 onwards), a community-led minimum size limit (MSL: 2002 to 2004) and a national ban on seahorse fishing (from 2004). The MSL appeared to lead to increased sizes of seahorses in trade, as hoped, while the national ban led, perversely, to more fishers selling seahorses. Declines in overall take after 2004 or 2007 (depending on the site) is likely linked to declining seahorse populations rather than reduced effort, especially when one considers the increased number of fishers and the price per seahorse. It is notable that communities decided on the MSL, whereas the government imposed the ban on capturing seahorses. In this small-scale, multi-species fishery, monitoring a wide range of variables intensively over a relatively long time scale allowed us to identify key differences between small-scale and industrial fisheries management, and also to document the biological and social consequences of management action for a depleted, threatened species. © The authors 2015. Source

Yasue M.,Quest University Canada | Yasue M.,University of British Columbia | Nellas A.,Project Seahorse Foundation for Marine Conservation | Vincent A.C.J.,University of British Columbia
Environmental Conservation

In marine environments, charismatic or economically valued taxa have been used as flagships to garner local support or international funds for the establishment and management of marine protected areas (MPAs). Seahorses (Hippocampus spp.) are frequently used as flagship species to help engender support for the creation of small community-managed no-take MPAs in the central Philippines. It is thus vital to determine whether such MPAs actually have an effect on seahorse abundance, reproductive status and size. A survey of seahorses inside and immediately adjacent to eight MPAs, and in four distant unprotected fishing areas, showed these MPAs had no significant effect on seahorse densities; although densities in and near MPAs were higher than in the distant fished sites, seahorse densities did not change over time. Seahorse size did show a marginal reserve effect, with slightly larger seahorses being found inside MPAs as compared to the distant unprotected fishing areas, but, in general, MPAs had little impact on seahorse size. Although MPAs may eliminate local fishing pressure, they may not reduce other threats such as pollution or destructive fishing outside the reserves. Other recovery tools, such as ecosystem-based management, habitat restoration and limits on destructive fishing outside of MPAs, may be necessary to rebuild seahorse populations. The effects of MPAs depend on species, as well as conditions outside the reserve boundaries. MPA management objectives must thus be clearly and realistically articulated to the communities, especially if support for an MPA was derived at least partly to conserve a particular flagship species. © Foundation for Environmental Conservation 2012. Source

Hansen G.J.A.,Michigan State University | Ban N.C.,University of British Columbia | Ban N.C.,James Cook University | Jones M.L.,Michigan State University | And 5 more authors.
Biological Conservation

Systematic approaches to site selection for marine protected areas (MPAs) are often favored over opportunistic approaches as a means to meet conservation objectives efficiently. In this study, we compared analytically the conservation value of these two approaches. We locate this study in Danajon Bank, central Philippines, where many MPAs were established opportunistically based on community preference, with few if any contributions from biophysical data. We began by identifying the biophysical data that would have been available when the first MPA was created in Danajon Bank (1995). We next used these data with the reserve selection software Marxan to identify MPAs that covered the same area as is protected under the current set of MPAs (0.32% of the total study area) and that would protect the greatest number of conservation targets at the lowest cost. We finally compared the conservation value of the current MPAs to the value of those selected by Marxan. Because of the dearth of biophysical data available in 1995 and the small area currently under protection, Marxan identified multiple configurations of MPAs that would protect the same percentage of conservation targets, with little differentiation among sites. Further, we discovered that the costs of obtaining and analyzing these data to be used for conservation planning would have been large relative to resources typically available to conservation planners in developing countries. Finally, we found that the current set of MPAs protected more ecological features than would be expected by chance, although not as many as could be protected using a systematic approach. Our results suggest that an opportunistic approach can be a valuable component of conservation planning, especially when biophysical data are sparse and community acceptance is a critical factor affecting the success of an MPA. © 2011 Elsevier Ltd. Source

Molloy P.P.,University of British Columbia | Molloy P.P.,Stantec Consulting Ltd. | Evanson M.,University of British Columbia | Evanson M.,Canadian Department of Fisheries and Oceans | And 5 more authors.
Aquatic Conservation: Marine and Freshwater Ecosystems

Coral-reef managers must detect and reverse collapses in habitat and evaluate the success of such interventions. Since these responsibilities must be met with limited time and resources, methods used should balance statistical power with practical and logistical constraints. Photoquadrat analysis is a commonly used method to survey coral habitats. This method, which involves photographing substratum along transects and digitally analysing habitat at points on the 'photoquadrats', affords efficiency in the field but is costly and requires extensive desk-based analysis. It remains unclear what is the optimal combination of sampling units (points, photoquadrats and transects) needed to detect important trends in coral habitat. Here, a dataset on Philippine coral-reef habitats, collected using intensive photoquadrat surveys, was used to explore the reliability of using different numbers of points per photoquadrat, photoquadrats per transect and transects per site to detect spatial differences in habitat. Results of leave-some-out analyses were compared with analysis of the complete dataset. Using fewer points per photoquadrat and fewer photoquadrats per transect caused little decline in ability to detect key trends, and lessened desk-based time; reducing the number of photoquadrats also lessened field time. Using fewer transects reduced time requirements but at the expense of statistical reliability. Prospective power analyses revealed that common rates of coral recovery could not be detected using even the most intensive photoquadrat protocols. This result implies that coral recoveries within protected areas might go undetected using standard surveying techniques. Using fixed rather than randomly placed photoquadrats, or more sensitive indicators of habitat recovery than coral cover (e.g. coral surface area) may improve power to detect coral recoveries. Finally, protocols that minimize desk time rarely also minimize field time and vice versa, which highlights the need to prioritize different logistical constraints when designing methods. © 2013 John Wiley & Sons, Ltd. Source

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