Evaluating the effectiveness of real-time closures for reducing susceptibility of small fish to capture

• Published in: ICES journal of marine science 2018-01, Vol.75 (1), p.298-308
• Main Authors: Woods, Pamela J, Þór Elvarsson, Bjarki, Sigurdsson, Thorsteinn, Stefánsson, Gunnar
• Format: Article
• Language: English
• ISSN: 1054-3139; 1095-9289
• DOI: 10.1093/icesjms/fsx152

Abstract Real-time spatial management in fisheries, a type of dynamic ocean management, uses nearly real-time data collection and dissemination to reduce susceptibility of certain species or age classes to being caught in mixed fisheries. However, as with many fisheries regulations, it is difficult to assess whether such a regulation can produce tangible results on population dynamics. In this study, we take advantage of a rare opportunity in which data regarding real-time closures (RTCs) are available for 1990–2014 alongside annual estimates of fishing mortality for three species (Atlantic cod, haddock, and herring) and catch for four species (all plus saithe) in Icelandic fisheries management. We use time series analyses to assess whether RTCs work as expected and yield a lower susceptibility of small fish to being caught, indicated by lower catch levels and selectivities (as estimated from fishing mortalities) in years with more closures. Results indicate that haddock and herring followed this pattern, but only under conditions of generally high fishing mortality. This study represents the first time evidence has been presented that real-time fishery closures can have a beneficial effect on population dynamics, but also suggests that results differ among species.