Bycatch of high sea longline fisheries and measures taken by Taiwan: Actions and challenges

Huang, Hsin-Hsiung

doi:10.1016/j.marpol.2011.02.012

Cited by 31 publications

(31 citation statements)

References 36 publications

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“…For example, in Taiwan, data from observers on the incidental catch of seabirds and sea turtles were scarce before 2005. With increased awareness of the importance of seabird populations and the marine ecosystem, a great deal of research on the estimation of seabird bycatch has been conducted worldwide, with the exception of the Atlantic Ocean (Huang & Liu, 2010;Huang, 2011;Huang & Yeh, 2011). We hope that our analysis can contribute to the scientific basis for further conservation work.…”

Section: Cooperation Between Scientists and Fishermenmentioning

confidence: 95%

“…However, observer programs are expensive and difficult to implement, particularly for distant water fishing fleets. To achieve the current 5% level, the annual budget for the Taiwanese longline observer program was over US$2 million per year (Huang, 2011). Despite this limitation, our study aimed to identify appropriate methodology to analyze observer data and provide sampling strategy.…”

Section: Strengthening Observer Programsmentioning

confidence: 99%

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Incidental catch of seabirds: strengthening observer programs and increasing cooperation

Huang

Yeh

2013

Animal Conservation

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Section: Cooperation Between Scientists and Fishermenmentioning

confidence: 95%

Section: Strengthening Observer Programsmentioning

confidence: 99%

Incidental catch of seabirds: strengthening observer programs and increasing cooperation

Huang

Yeh

2013

Animal Conservation

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“…Considering the fishing effort that the pelagic longline fleets expend over the region of the BMC, undoubtedly the area of greatest concentration of effort over the last decades in the southwest Atlantic (Tuck et al 2003;Lewison et al 2005;Huang 2011), there is no doubt that some populations are seriously affected. Fleets flying the flags of Taiwan, Japan, Spain, and Brazil, among others (see ICCAT, Task II Catch & Effort (T2CE) http://iccat.int/Data/t2ce.rar), operate in this region throughout the year.…”

Section: Implications For Conservationmentioning

confidence: 99%

Risk assessment and relative impact of Uruguayan pelagic longliners on seabirds

Jiménez

Domingo²,

Abreu³

et al. 2012

Aquat. Living Resour.

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-Bycatch in longline fisheries is considered one of the main threats for the conservation of albatrosses and petrels worldwide. However, the relative impact of fisheries on all the affected populations or species still remains poorly understood. This paper applied a Productivity and Susceptibility Analysis (PSA) and the concept of "Potential Biological Removal Level" (PBR) to assess the relative impact caused by the Uruguayan pelagic longline fishery on several populations. This two-step approach allowed us to obtain an objective view of the relative impact of the Uruguayan pelagic longline fleet on most of the populations or species of albatrosses and petrels with high association with this fishery. Of fifteen species considered, fourteen were finally assessed and a ranking of risk derived. The concept of PBR was applied to the nine most at-risk species. The impact of fishing on populations could not be straightforwardly inferred from their bycatch rates. Results indicate that large albatrosses (Diomedea spp.) and Thalassarche chlororhynchos are more affected than some of the main species caught by the fishery (i.e. Thalassarche melanophrys and Procellaria aequinoctialis). Diomedea exulans from South Georgia is likely to be the population most affected by the Uruguayan fleet. This work should be seen as a case study of the fisheries operating in the southwestern Atlantic. The Uruguayan fleet within its operation area was responsible for only the 4.3% to 12.5% of the total annual effort deployed by the different fleets during 2004−2008. The combined impact of these fleets could be sufficiently high to account for many of the observed declines in the populations of D. exulans, D. dabbenena and T. chlororhynchos. However, the seabird bycatch numbers for most of the pelagic longline fleets that operate in the southwest Atlantic remain unknown. Applying mitigation measures to reduce the impact of pelagic longline fleets operating in this region should be considered a high priority.

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“…Of the species that made significant use of discards in our study area, 8 species of albatross and petrel are globally threatened, including 1 listed as Critically Endangered and 3 as Endangered (Table 2). Considering the fishing effort (an indirect measure of discards) that the pelagic longline fleets expend over the region of the BMC, the area of greatest concentration of effort in the southwestern Atlantic (Tuck et al 2003, Huang 2011, see also ICCAT, Task II Catch & Effort, T2CE, at http://iccat. int/en/accesingdb.htm), there is no doubt that discards are an important source of food for these populations.…”

Section: Implications For Bycatchmentioning

confidence: 99%

Structure of the seabird assemblage associated with pelagic longline vessels in the southwestern Atlantic: implications for bycatch

Jiménez¹,

Domingo²,

Abreu³

et al. 2011

Endang. Species. Res.

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The region of the southwest Atlantic influenced by the Brazil-Malvinas Confluence (BMC) is important for globally threatened species of albatross and petrel. This applies particularly to the area of the continental slope, due to the high rates of incidental catch from pelagic longliners. We analyzed the temporal variation in the seabird assemblage associated with this fishery, identified the species that make use of discards, and evaluated their interactions while foraging. During 20 commercial fishing trips between 2005 and 2008, we completed 415 bird counts and recorded behavior in 172 of these. The observed species richness (≥38 species) is greater than that reported for any other fishery in the region and was highest from October to April, although many species in the assemblage were significantly more abundant between May and September. Only 14 species made significant use of discards, and all of these were albatrosses and petrels captured incidentally. We observed within-and between-species competition for access to discards. In general, the frequency of intraspecific competition was greater in the most abundant species, during the period of their greatest abundance. Albatrosses were more successful in interspecific competitive interactions, and we observed a dominance hierarchy related to body size. We conclude that the composition and seasonality of the seabird bycatch is determined by the spatiotemporal dynamics of the assemblage and by the observed pattern of interspecific interactions. Discards from pelagic longline fleets operating in the BMC may be an important food source for at least 8 species of globally threatened seabirds. Understanding the effect of discards on these populations could generate useful information for conservation, although reducing bycatch levels should be considered the main goal.

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Bycatch of high sea longline fisheries and measures taken by Taiwan: Actions and challenges

Cited by 31 publications

References 36 publications

Incidental catch of seabirds: strengthening observer programs and increasing cooperation

Incidental catch of seabirds: strengthening observer programs and increasing cooperation

Risk assessment and relative impact of Uruguayan pelagic longliners on seabirds

Structure of the seabird assemblage associated with pelagic longline vessels in the southwestern Atlantic: implications for bycatch

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