title: Derelict fishing line provides a useful proxy for estimating levels of non-compliance with no-take marine reserves.
abstract: No-take marine reserves (NTMRs) are increasingly being established to conserve or restore biodiversity and to enhance the sustainability of fisheries. Although effectively designed and protected NTMR networks can yield conservation and fishery benefits, reserve effects often fail to manifest in systems where there are high levels of non-compliance by fishers (poaching). Obtaining reliable estimates of NTMR non-compliance can be expensive and logistically challenging, particularly in areas with limited or non-existent resources for conducting surveillance and enforcement. Here we assess the utility of density estimates and re-accumulation rates of derelict (lost and abandoned) fishing line as a proxy for fishing effort and NTMR non-compliance on fringing coral reefs in three island groups of the Great Barrier Reef Marine Park (GBRMP), Australia. Densities of derelict fishing line were consistently lower on reefs within old (>20 year) NTMRs than on non-NTMR reefs (significantly in the Palm and Whitsunday Islands), whereas line densities did not differ significantly between reefs in new NTMRs (5 years of protection) and non-NTMR reefs. A manipulative experiment in which derelict fishing lines were removed from a subset of the monitoring sites demonstrated that lines re-accumulated on NTMR reefs at approximately one third (32.4%) of the rate observed on non-NTMR reefs over a thirty-two month period. Although these inshore NTMRs have long been considered some of the best protected within the GBRMP, evidence presented here suggests that the level of non-compliance with NTMR regulations is higher than previously assumed.
authors.affiliation: Australian Research Council Centre of Excellence for Coral Reef Studies, Townsville, Queensland 4811, Australia.
authors.forename: David H
authors.initials: DH
authors.lastname: Williamson
authors.affiliation: Australian Research Council Centre of Excellence for Coral Reef Studies, Townsville, Queensland 4811, Australia.
authors.forename: Daniela M
authors.initials: DM
authors.lastname: Ceccarelli
authors.affiliation: Department of Parks and Wildlife, 17 Dick Perry Ave., Kensington, Perth, Western Australia 6151, Australia; Oceans Institute, School of Plant Biology, University of Western Australia, Crawley, WA 6009, Australia.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Evans
authors.affiliation: Olazul, 150 Post Street, Suite 342, San Francisco, CA, 94108, United States of America.
authors.forename: Jos K
authors.initials: JK
authors.lastname: Hill
authors.affiliation: Australian Research Council Centre of Excellence for Coral Reef Studies, Townsville, Queensland 4811, Australia; James Cook University, School of Marine and Tropical Biology, Townsville, Queensland 4811, Australia.
authors.forename: Garry R
authors.initials: GR
authors.lastname: Russ
mesh_terms: D000818:Animals; D001315:Australia; D044822:Biodiversity; D003247:Conservation of Natural Resources; D005398:Fisheries; D005399:Fishes; D009792:Oceans and Seas