Electrofishing as a potential threat to freshwater cetaceans

Thomas, Peter O.; Gulland, Frances M. D.; Reeves, Randall R.; Kreb, Daniëlle; Wang, Ding; Smith, Brian D.; Malik, Muhammad Imran; Ryan, Gail; Phay, Somany

doi:10.3354/esr00962

Cited by 12 publications

(17 citation statements)

References 28 publications

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“…A range-wide survey in late 2017 found similar numbers as in the 2012 survey, a hopeful sign (Mei et al 2018), but additional surveys are needed to determine the current trend of the population. These porpoises are threatened by bycatch in several types of non-selective fishing gear, including gillnets and bottom-set 'rolling-hooks longlines', as well as by, to a lesser degree, electrofishing (Thomas et al 2019), ship strikes, sand dredging, pollution, and water development projects (Mei et al 2012).…”

Section: Yangtze Finless Porpoise Neophocaena Asiaeorientalis Asiaeormentioning

confidence: 99%

“…The main threat is bycatch in gillnets, which accounted for two-thirds of the deaths with a known cause between 1995 and 2016. Other threats include deaths from vessel strikes, deliberate hunting, possibly electrofishing (but see Thomas et al 2019), habitat degradation, prey depletion caused by over-fishing, the conversion of fish spawning areas into palm oil plantations, and sedimentation of lake habitat (Kreb et al 2007, Thomas & Gulland 2017. At a minimum, bycatch and direct takes must be eliminated if this population is to be saved.…”

Section: Mahakam River Dolphin or Pesut O Brevirostris (Subpopulation)mentioning

confidence: 99%

“…Between 2002 and 2017, an average of 2.5 dolphin deaths was reported annually. The greatest threat is entanglement in gillnets, but there is also concern about possible mortality related to electrofishing (see Thomas et al 2019). Sedimentation and mercury toxicity from gold mining and dams on the Taping and Shweli tributaries have degraded the dolphins' habitat (Smith & Tun 2007).…”

Section: Irrawaddy Dolphin O Brevirostris (Subpopulation)mentioning

confidence: 99%

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Bycatch in gillnet fisheries threatens Critically Endangered small cetaceans and other aquatic megafauna

Brownell¹,

Reeves²,

Read³

et al. 2019

Endang. Species. Res.

Self Cite

139

123

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The conservation status of small cetaceans has significantly worsened since the 1980s, when the baiji was the only species of small cetacean listed as Endangered by IUCN. Now the baiji is almost certainly extinct and 13 other species, subspecies, or populations (hereafter units-to-conserve or units) of small cetaceans are listed as Critically Endangered (CR) on the IUCN Red List. Bycatch is the main threat to 11 of the CR units. Entanglement in gillnets contributed to the extinction of the baiji and is responsible for the imminent extinction of the vaquita. Unfortunately, there is no simple technical solution to the problem of bycatch of small cetaceans. If the 8 CR units with 100 or fewer remaining individuals are to be saved, conservation zones must be established where gillnets are eliminated and bans on their use are strictly enforced. Recent experience with the vaquita in Mexico demonstrates that enforcement of such conservation zones can be very difficult. Ineffective enforcement is also a problem for at least 4 of the other CR units. Time is very short and, unless major efforts are made now to address the bycatch problem, the prospects for CR small cetaceans and other at-risk aquatic megafauna are grim. The ultimate long-term solution to the bycatch problem is the development of efficient, inexpensive, alternative fishing gear that can replace gillnets without jeopardizing the livelihoods of fishermen. Good fishery governance and the direct involvement of fishing communities are also essential to the successful conservation of most threatened populations of small cetaceans.

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Section: Yangtze Finless Porpoise Neophocaena Asiaeorientalis Asiaeormentioning

confidence: 99%

Section: Mahakam River Dolphin or Pesut O Brevirostris (Subpopulation)mentioning

confidence: 99%

Section: Irrawaddy Dolphin O Brevirostris (Subpopulation)mentioning

confidence: 99%

See 1 more Smart Citation

Bycatch in gillnet fisheries threatens Critically Endangered small cetaceans and other aquatic megafauna

Brownell¹,

Reeves²,

Read³

et al. 2019

Endang. Species. Res.

Self Cite

139

123

View full text Add to dashboard Cite

show abstract

“…Similar fishing banning practice can adopt in the Ayeyarwdy River. Electric fishing and entanglement in gill nets were the most significant threats to the conservation of Irrawaddy dolphins in the Ayeyarwady River (Smith & Tun, 2007; Thomas et al, 2019). Entanglements and mortality were commonly observed wherever gill nets and cetaceans occur together (Brownell et al, 2019; Perrin, Donovan,& Barlow, 1994; Northridge, Coram, Kingston, & Crawford, 2017).…”

Section: Discussionmentioning

confidence: 99%

“…Electric and gill net fishing were formerly identified as the most significant threats to Irrawaddy dolphins in the Ayeyarwady River (Smith & Tun, 2007;Thomas et al, 2019), however, due to short-staffed situation, these parameters were not exhaustively quantified in our survey. There is a possibility that dolphins move upstream at night and would then be counted twice.…”

Section: Possible Limitations Of Our Studymentioning

confidence: 99%