Estimating illegal and unreported catches from marine ecosystems: a basis for change

Abstract

To evaluate the impacts of fishing on marine ecosystems, the total extraction of fish must be known. Putting a figure on total extraction entails the difficult task of estimating, in addition to reported landings, discards, illegal and unmandated catches. Unreported catches cast various types of shadow, which may be tracked and estimated quantitatively. Some shadows of unreported catches are reviewed, for example, an innovative, well‐funded NGO publicizes illegal catch in the Southern Ocean. For various reasons, official figures often have the implicit but unacceptable assumption that such categories are null. We present an estimation procedure based on adjustment factors taken from observer reports, correspondents and published information that track changes in a regulatory regime, and hence reflect incentives and disincentives to misreport. Monte Carlo simulations address uncertainty using multiple sources of information to provide upper and lower estimates. Once in place, this method provides preliminary estimates that may be refined without disruption. The method is demonstrated for fisheries in Iceland and Morocco. We use a ‘by‐species’ approach for Icelandic cod and haddock, while the Moroccan catch is divided into demersal and pelagic categories. Results suggest that Icelandic cod catches may have been underestimated by between 1 and 14% at different times, and haddock by between 1 and 28%. Underestimation of Moroccan catches appears to have been as much as by 50%. These case studies show that it is possible to obtain estimates of misreporting, even when direct data are lacking. Our method encourages transparency because sources of information are presented so that uncertain values are easily identified, offering a basis for comment, collaboration and refinement in estimating illegal and unreported fishing.

Análise etnoictiológica da pesca artesanal nas bacias hidrográficas dos Rios Uruguai e Jacuí­­, Rio Grande do Sul, Brasil

“…Ela engloba diversas ações relatadas pelos pescadores, tais como: captura de espécimes de tamanho inferior ao permitido, como juvenis; pesca em período de piracema e em locais proibidos (lagos de barragens hidrelétricas, fora da margem permitida do rio e pesca em afluentes); pesca com petrechos de uso proibido (tarrafa, rede de emalhar inferior a sete centímetros entre nós (BHJ) e seis centímetros entre nós (BHU), covo, garateia e boia louca). A pesca ilegal gera danos colaterais significativos aos ecossistemas, como reduções de estoques pesqueiros, através da sobre-explotação destes recursos (PITCHER et al, 2002;AGNEW et al, 2011;WELCOMME et al, 2010). Além disso, a prática de tais ações é penalizada conforme os consta nos artigos 29 e 34 da Lei nº 9.605/98.…”

A Sociopolitical Perspective on the Illegal Take of Wildlife in the Southeastern, USA

“…As such, a complete understanding of behavioral triggers or how behavior changes when the sociopolitical context changes remains elusive and undertheorized. With a more comprehensive understanding of why hunters engage in the illegal take of wildlife, managers might design more efficient interventions to reduce policy breaches before they have negative biological and social impacts (Pitcher, Watson, Forrest, Valtýsson, and Guénette 2002). Moreover, it may help shift wildlife agency focus from the individual to broader and perhaps unanticipated behavioral drivers, such as environmental or social policies (Bell, Hampshire, and Topalidou 2007), wildlife management agency assumptions about poaching (Enck and Decker 1997), or deeply rooted cultural norms (Grigsby 2011;Fortsyth, Gramling, and Wooddell 1998).…”

Destructive fishing and fisheries enforcement in eastern Indonesia

“…Illegal, unreported, and unregulated (IUU) fishing is gaining attention around the world, with fisheries scientists listing it as a major barrier to the sustainability of marine resource use (Pitcher et al 2002, Sumaila et al 2006, and this is certainly true of destructive fishing in Indonesia (Pet-Soede & Erdmann 1998, Pet-Soede et al 1999, Halim & Mous 2006. IUU fishing can undermine management programs (FAO 2002) because it can lead to underestimation of catch and effort (Pitcher et al 2002).…”

“…IUU fishing can undermine management programs (FAO 2002) because it can lead to underestimation of catch and effort (Pitcher et al 2002). Furthermore, dynamite and cyanide fishing can negatively affect fish habitat, and are thus inherently unsustainable fishing methods (Pauly 1989).…”