Preventing overexploitation of migratory fish stocks: the efficacy of marine protected areas in a stochastic environment

West, C D, Dytham, C, Righton, D Pitchford, J. W. Prevention of overdevelopment of sexual fishes resources over 2009: Effectiveness of ocean protected areas in random environment - ICES Journal of Marine Science, 66: 1919-1930

Marine protected areas (marine protected areas) are widely proposed to protect overfished fish species. It is suggested that individuals can strengthen their fishery by flowing out from the marine protected area to the fishery. However, traditional spillover studies have failed to explain the seasonal movement of many groups. Most fishery models also do not explicitly include randomness inherent in the marine environment. Here we use a simple population model to simulate the migration of fish farms between the MPA and the fishery to evaluate the effectiveness of the MPA. Including realistic environmental randomness in our model allows the population to deviate from positive stable equilibrium and switch the correct stable equilibrium, which is impossible with deterministic analysis. In the case of deterministic analysis predicting persistence of the population, this bias can lead to the collapse of the population. MPA is effective at lower migration levels, but as migration increases the ability to protect inventory from collapse may decline. However, MPA provides higher protection and higher expected fishery yields, regardless of transition level, than MPA-less system. By combining MPA and harvest management rules you can further increase protection and yield. Therefore, we believe that marine protected areas can play a role in protecting migratory species.

Ocean fishery is a major cause of the massive decline of marine ecosystems and natural habitats and often results in "overfished" areas and populations (indeed, the 10 most captured fish were "overfished" It is classified as). Few people think how rapid population decline affects their environment. Later, these fish are either discarded by consumers or rejected at stores to not meet specific criteria, or rot in trucks (in developing countries) due to lack of modern refrigeration equipment.

Marine protected areas (marine protected areas) are widely proposed to protect overfished fish species. It is suggested that individuals can strengthen their fishery by flowing out from the marine protected area to the fishery. However, traditional spillover studies have failed to explain the seasonal movement of many groups. Most fishery models also do not explicitly include randomness inherent in the marine environment. Here we use a simple population model to simulate the migration of fish farms between the MPA and the fishery to evaluate the effectiveness of the MPA. Including realistic environmental randomness in our model allows the population to deviate from positive stable equilibrium and switch the correct stable equilibrium, which is impossible with deterministic analysis. In the case of deterministic analysis predicting persistence of the population, this bias can lead to the collapse of the population. By combining MPA and harvest management rules you can further improve protection and yield.

Prevention of excessive development of migratory fish: effectiveness of ocean protected areas in random environment

Regarding the proportion of fish stock within safe biological limits, overfishing in marine fishery reached new heights in 2008. According to FAO, about 30% of aquatic fish resources were overfished in 2009 27. The resources used in the index on the percentage of the total water volume, the UN Millennium Development Goals Report 2011, 2011, indicates that progress is slow or not progressing. Goal 7c: Sustainable access to safe drinking water and halve the proportion of people who can not use basic sanitation facilities by 2015. The UN Millennium Development Goals Report in 2012 shows that the world has reached the global goal of access to safe drinking water but the progress toward achieving health goals has been delayed . Do not underestimate the importance of achieving drinking water goals. Millions of people can get safer water. But there are still many things to do