Tag species to prevent illegal fishing or harvesting
Overall effectiveness category Unknown effectiveness (limited evidence)
Number of studies: 1
Background information and definitions
Many populations of marine subtidal benthic invertebrate species have declined or been depleted due to the multiple threats they are under, including overharvest (Hobday et al. 2000). Populations of certain species have declined to such extent that they are now protected, and their fishing and harvesting is controlled and/or illegal (Stierhoff et al. 2012). For species for which fishing or harvesting is forbidden, animals can be tagged to deter illegal capture and potentially help reduce their population declines (Lewis 2015).
Evidence for related interventions is summarised under “Threat: Biological resource use – Set commercial catch quotas”, and “Species management – Set recreational catch quotas” and “Etablish size limitations for the capture of recreational species”.
Hobday A.J., Tegner M.J. & Haaker P.L. (2000) Over-exploitation of a broadcast spawning marine invertebrate: decline of the white abalone. Reviews in Fish Biology and Fisheries, 10, 493–514.
Lewis S.G. (2015) Bags and tags: randomized response technique indicates reductions in illegal recreational fishing of red abalone (Haliotis rufescens) in Northern California. Biological Conservation, 189, 72–77.
Stierhoff K.L., Neuman M. & Butler J.L. (2012) On the road to extinction? Population declines of the endangered white abalone, Haliotis sorenseni. Biological Conservation, 152, 46–52.
Supporting evidence from individual studies
A before-and-after study in 2007 and 2011 of fishers surveyed across 11 sites in northern California, USA (Lewis 2015) found that introducing tagging regulation did not reduce overall illegal takes of red abalone Haliotis rufescens. Tagging led to a 4% reduction in illegal takes of abalone, but this was not statistically significant. Of the seven categories of illegal takes considered, only non-compliance with daily-take quotas significantly reduced (before tagging: 32%; after tagging: 19%), particularly amongst local fishers (before: 72%; after: 43%). The other six categories were not significantly reduced (see paper for details). Red abalone tagging regulation was introduced in California between 2007 and 2011 (date unspecified). Over five weeks in August–September 2007 and 2011, fishers at 11 sites where abalone harvest is restricted were asked to respond to a set questionnaire regarding their compliance to each of seven regulations. Proportional non-compliance across fishers was estimated for each regulation and overall.Study and other actions tested