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Providing evidence to improve practice

Individual study: Bags and tags: randomized response technique indicates reductions in illegal recreational fishing of red abalone (Haliotis rufescens) in Northern California

Published source details

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


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Tag species to prevent illegal fishing or harvesting Subtidal Benthic Invertebrate Conservation

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.

(Summarised by Anaëlle Lemasson)