For the last few years, I have been involved with a collaborative research project investigating the effectiveness of periodically harvested fisheries closures (PHCs). Widely implemented by local communities across Melanesia, periodically harvested closures restrict fishing activities for specified periods of time.
PHCs evolved primarily to serve social and cultural objectives. For example, in Fiji and Papua New Guinea, communities traditionally closed areas of fishing ground for 100 days following the death of a respected community member – the area would then be opened to harvest fish for a funeral. In contemporary use however, PHCs are often expected to achieve a wide range of objectives, including maximising yields in the short-term, boosting fisheries sustainability in the long-term, and contributing towards biodiversity conservation goals.
However, there are few empirical data measuring the effectiveness of PHCs, and it remains unclear whether they can achieve any or all of these objectives simultaneously, or what factors might be critical to their success. In a paper just out in the Journal of Applied Ecology led by Jordan Goetze, we present a novel analytical framework to guide a meta-analysis and assist future research in conceptualizing and assessing the potential of PHCs to deliver benefits for multiple fisheries-related objectives.
This paper was largely written during a very enjoyable weeklong workshop in Albany, Western Australia, during which we were treated to sustainable seafood (we caught squid from the jetty and cockles in the bay ourselves!) cooked by Paul Iskov from Fevor (the chef is acknowledged in the paper).
Goetze, J. S., Claudet, J., Januchowski-Hartley, F., Langlois, T. J., Wilson, S. K., White, C., Weeks, R. & Jupiter, S.D.J. (2017). Demonstrating multiple benefits from periodically harvested fisheries closures. Journal of Applied Ecology.
1. Periodically harvested closures (PHCs) are one of the most common forms of fisheries management in Melanesia, demonstrating multiple objectives, including sustaining fish stocks and increasing catch efficiency to support small-scale fisheries. No studies have comprehensively assessed their ability to provide short-term fisheries benefits across the entire harvest regime.
2. We present a novel analytical framework to guide a meta-analysis and assist future research in conceptualizing and assessing the potential of PHCs to deliver benefits for multiple fisheries-related objectives.
3. Ten PHCs met our selection criteria and on average, they provided a 48% greater abundance and 92% greater biomass of targeted fishes compared with areas open to fishing prior to being harvested.
4. This translated into tangible harvest benefits, with fishers removing 21% of the abundance and 49% of the biomass within PHCs, resulting in few post-harvest protection benefits.
5. When PHCs are larger, closed for longer periods or well enforced, short-term fisheries benefits are improved. However, an increased availability of fish within PHCs leads to greater removal during harvests.
6. Synthesis and applications. Periodically harvested closures (PHCs) can provide short-term fisheries benefits. Use of the analytical framework presented here will assist in determining long-term fisheries and conservation benefits. We recommend PHCs be closed to fishing for as long as possible, be as large as possible, that compliance be encouraged via community engagement and enforcement, and strict deadlines/goals for harvesting set to prevent overfishing.