Banning is not enough: The complexities of oceanic shark management by tuna regional fisheries management organizations

Tolotti, Mariana Travassos; Filmalter, John David; Bach, Pascal; Travassos, Paulo; Séret, Bernard; Dagorn, Laurent

doi:10.1016/j.gecco.2015.05.003

Cited by 37 publications

(35 citation statements)

References 50 publications

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“…In the North Atlantic, this species declined by 50% from 1992 to 2005 (Baum & Blanchard ) and is currently protected by several RFMOs, including ICCAT (Tolotti et al. ). Our results are generally supported by independent assessment and approaches, such as demographic and productivity and susceptibility analysis, which indicate that some Carcharhinidae species are at great risk of extinction in the SAO, specifically Carcharhinus signatus , C. galapagensis , C. falciformis , and C. longimanus (Santana et al.…”

Section: Discussionmentioning

confidence: 99%

“…The ICCAT banned the shark fin fishery in 2004, and from 2008 to 2011 a series of recommendations were made for nonretention and commercialization of several endangered oceanic sharks (Tollotti et al. ). Since 2006, Brazil has required that all foreign vessels host onboard observers.…”

Section: Methodsmentioning

confidence: 99%

“…Since 2008, the International Commission for the Conservation of Atlantic Tunas (ICCAT), the main RFMO managing pelagic fisheries in the Atlantic, has recommended no retention, catch, or commercialization of some of the species exploited by these fisheries, including all sphyrnids (hammerhead sharks) and bigeye thresher, oceanic white‐tip, and silky sharks ( Alopias superciliosus , Carcharhinus longimanus , and C. falciformis respectively) (Tolotti et al. ). The Brazilian Ministry of the Environment has attempted to protect these species by including them in the national list of endangered species (ICMBio ).…”

Section: Introductionmentioning

confidence: 99%

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Trends in the exploitation of South Atlantic shark populations

Barreto

Ferretti

Flemming

et al. 2016

Conservation Biology

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Approximately 25% of globally reported shark catches occur in Atlantic pelagic longline fisheries. Strong declines in shark populations have been detected in the North Atlantic, whereas in the South Atlantic the situation is less clear, although fishing effort has been increasing in this region since the late 1970s. We synthesized information on shark catch rates (based on 871,177 sharks caught on 86,492 longline sets) for the major species caught by multiple fleets in the South Atlantic between 1979 and 2011. We complied records from fishing logbooks of fishing companies, fishers, and onboard observers that were supplied to Brazilian institutions. By using exploratory data analysis and literature sources, we identified 3 phases of exploitation in these data (Supporting Information). From 1979 to 1997 (phase A), 5 fleets (40 vessels) fished mainly for tunas. From 1998 to 2008 (phase B), 20 fleets (100 vessels) fished for tunas, swordfishes, and sharks. From 2008 to 2011 (phase C), 3 fleets (30 vessels) fished for multiple species, but restrictive measures were implemented. We used generalized linear models to standardize catch rates and identify trends in each of these phases. Shark catch rates increased from 1979 to 1997, when fishing effort was low, decreased from 1998 to 2008, when fishing effort increased substantially, and remained stable or increased from 2008 to 2011, when fishing effort was again low. Our results indicate that most shark populations affected by longlines in the South Atlantic are currently depleted, but these populations may recover if fishing effort is reduced accordingly. In this context, it is problematic that comprehensive data collection, monitoring, and management of these fisheries ceased after 2012. Concurrently with the fact that Brazil is newly identified by FAO among the largest (and in fastest expansion) shark sub-products consumer market worldwide.

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Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Trends in the exploitation of South Atlantic shark populations

Barreto

Ferretti

Flemming

et al. 2016

Conservation Biology

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“…Many shark and ray species are highly migratory and overexploited; therefore, they may require international management efforts such as bilateral and multilateral fisheries management agreements (Musick et al 2000;Herndon et al 2010). The conservation status and management measures for many shark and ray species have been evaluated by international conservation organizations, and the policies for conservation are mainly based on retention bans, finning bans and trading bans intended to promote the recovery of shark populations (Tolotti et al 2015). Like many other international policies these organizations do not have any initiatives that deal specifically with genetic diversity.…”

Section: Conservation Policies Have Overlooked and Neglected Shark Anmentioning

confidence: 99%

The importance of considering genetic diversity in shark and ray conservation policies

2017

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Many populations of elasmobranchs (sharks and rays) are experiencing severe declines due to the high demand for shark fins in Asia, the activities of unregulated fisheries, and increases in shark and ray catches. Recently, the effects of the decline in the populations of marine fish species on genetic diversity have drawn increasing attention; however, only a few studies have addressed the genetic diversity of shark and ray populations. Here, we report the results of a quantitative analysis of the genetic diversity of shark and ray species over the past 20 years and discuss the importance and utility of this genetic information for fisheries management and conservation policies. Furthermore, we suggest future actions important for minimizing the gaps in our current knowledge of the genetic diversity of shark and ray species and to minimize the information gap between genetic scientists and policymakers. We suggest that shark and ray fisheries management and conservation policies consider genetic diversity information, such as the management unit, effective population size (Ne), haplotype and nucleotide diversity, observed heterozygosity, and allelic richness, because the long-term survival of a species is strongly dependent on the levels of genetic diversity within and between populations. In addition, sharks and rays are a group of particular interest for genetic conservation due to their remarkable life histories.

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“…As such, the measures currently in place do little to alleviate fishing mortality, which continues to impact oceanic whitetip populations across all oceans. The development of mitigation measures capable of not only reducing their catch rates but also increasing their post-release survival are therefore crucial for improving population levels [ 6 ]. In ecological terms, the vulnerability of a species depends upon two factors: the sensitivity of the species to an external factor and how extensive the exposure to this hazard is [ 7 , 8 ].…”

Section: Introductionmentioning

confidence: 99%

Vulnerability of the Oceanic Whitetip Shark to Pelagic Longline Fisheries

et al. 2015

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A combination of fisheries dependent and independent data was used to assess the vulnerability of the oceanic whitetip shark to pelagic longline fisheries. The Brazilian tuna longline fleet, operating in the equatorial and southwestern Atlantic, is used as a case study. Fisheries dependent data include information from logbooks (from 1999 to 2011) and on-board observers (2004 to 2010), totaling 65,277 pelagic longline sets. Fisheries independent data were obtained from 8 oceanic whitetip sharks tagged with pop-up satellite archival tags in the area where longline fleet operated. Deployment periods varied from 60 to 178 days between 2010 and 2012. Tagging and pop-up sites were relatively close to each other, although individuals tended to travel long distances before returning to the tagging area. Some degree of site fidelity was observed. High utilization hotspots of tagged sharks fell inside the area under strongest fishing pressure. Despite the small sample size, a positive correlation between tag recorded information and catch data was detected. All sharks exhibited a strong preference for the warm and shallow waters of the mixed layer, spending on average more than 70% of the time above the thermocline and 95% above 120 m. Results indicate that the removal of shallow hooks on longline gear might be an efficient mitigation measure to reduce the bycatch of this pelagic shark species. The work also highlights the potential of tagging experiments to provide essential information for the development of spatio-temporal management measures.

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Banning is not enough: The complexities of oceanic shark management by tuna regional fisheries management organizations

Cited by 37 publications

References 50 publications

Trends in the exploitation of South Atlantic shark populations

Trends in the exploitation of South Atlantic shark populations

The importance of considering genetic diversity in shark and ray conservation policies

Vulnerability of the Oceanic Whitetip Shark to Pelagic Longline Fisheries

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