دانلود رایگان مقاله نیاز به حفاظت گونه آسیب پذیر جهت تعطیلی دوره برداشت

ABSTRACT

Periodically harvested closures (PHCs) are small fisheries closures with objectives such as sustaining fisheries and conserving biodiversity and have become one of the most common forms of nearshore marine management in the Western Pacific. Although PHCs can provide both short-term conservation and fisheries benefits, their potential as a long-term management strategy remains unclear. Through empirical assessment of a single harvest event in each of five PHCs, we determined whether targeted fishes that differ in their vulnerability to fishing recovered to pre-harvest conditions (the state prior to last harvest) and demonstrated post-harvest recovery benefits after 1 year of re-closure. For low and moderately vulnerable species, two PHCs provided significant preharvest benefits and one provided significant post-harvest recovery benefits, suggesting a contribution to longer-term sustainability. PHCs with a combination of high compliance and longer closing times are more likely to provide fisheries benefits and recover from harvest events, however, no benefits were observed across any PHCs for highly vulnerable species. We recommend PHCs have longer closure periods before being harvested and species that are highly vulnerable to fishing (e.g. large species of; grouper, wrasse and parrotfish) are avoided during harvests to avoid overexploitation and increase the sustainability of small-scale fisheries.

4.1. Conclusions

PHCs in Fiji are capable of providing pre-harvest and harvest benefits primarily for low to moderately vulnerable species. However, closing PHCs for just 1 year in most cases will provide little long-term benefit to fishers and is not sufficient for the recovery of pre-harvest benefits required for sustainability of the harvest regime. Identification of the precise harvest regimes for sustainability of the PHC strategy will require studies over large temporal scales (i.e. decades) that integrated variable harvesting regimes, as seen with long-term studies of marine reserves (McClanahan and Humphries, 2012; Russ and Alcala, 2004, 2003). However, PHCs are already extant across the Western Pacific, where smallscale fisheries are often essential for food security and livelihood, meaning these communities cannot afford such delays in management advice to help sustain these fisheries. Alternative methods such as population modelling that uses the empirical data currently available may provide further insight into the management of PHCs. While continued studies are important, we recommend that PHCs are closed to fishing for greater than 1 year, with a strong recommendation for 3 years or more to increase the potential for short-term ecological benefits and long-term sustainability of small-scale fisheries, and that highly vulnerable species are protected from harvests. It is also important that PHCs are used in conjunction with conventional fisheries management strategies,which will promote the recovery of coral reef fisheries (MacNeil et al., 2015). Similarly, we recommend that permanent, no-take marine reserves are used for conservation of biodiversity (Costello and Ballantine, 2015), given that PHCs are unlikely to provide long-term conservation benefits. Supplementary data to this article can be found online at http://dx. doi.org/10.1016/j.biocon.2016.08.038.