A ban on shark fishing is only partially effective in protecting sharks, a new study suggests.
Scientists from the University of Exeter, the international conservation charity ZSL (Zoological Society of London) and Sri Lankan NGO Oceanswell studied the effects of blanket ban on bats, introduced by the Sri Lankan government in 2012.
Information gathered from local fishermen shows that the ban has stopped targeted shark fishing – but “bycatch” (unannounced capture) continues.
The study also found that bycatch appears to be widely reported, partly due to “poor trust and confusion” among fishermen.
“Sri Lanka’s long-term ban allows us to assess the effects of a ban, which is increasingly being implemented globally to protect sharks,” said lead author Claire Collins, from University Exeter and ZSL Institute of Zoology.
“The ban has stopped targeted shark fishing, so it has been a great success.
“However, persistent bycatch is a problem not only because of the direct impact on this vulnerable species, but also because it makes it terrible for fishermen to get around the ban.
“Because beaters, like other shark species, are as easy to hide by cutting off wings before landing, fishermen can easily sell them and the ban can be difficult for authorities to enforce.
“Without a sustained bycatch, these sharks will always be tempted – especially as Sri Lanka has a strong market for shark meat as well as fines.”
The study does not address ways to reduce by-catch, but measures could include banning local fishing in areas known for sharks, changing fishing gear, and reducing the amount of time gear remains in the water so that sharks caught by accident before have a higher chance of dying.
Oceanswell researchers collected data from fishermen over a decade last year.
Despite many fishermen reporting being segregated by authorities prior to the ban, compliance was very high among communities that used to depend on beaters for their livelihoods.
The study notes the “unequal” effects of the ban.
Not surprisingly, it was most affected by fishermen involved in targeted shark fishing, and the researchers say such impacts should be minimized where possible.
Dr Ana Nuno, lead author of the paper, based at the University of Exeter and the University of NOVA Lisbon (Portugal), said: “If we want conservation and fisheries policies to work, we need to better understand how they could affect consumer convenience and take this into account during policy design.
“That is crucial to implementing strong policies that deliver positive outcomes for people and biodiversity.”
The paper, published in the journal Maritime Policy, with the title: “Using Ideas to Examine People ‘s Responses to Blanket Ban: A case of a shark ban ban in Sri Lanka.”
Netting releases sharks off the hook
Claire Collins et al. Maritime Policy (2020). DOI: 10.1016 / j.marpol.2020.104198
Presented by the University of Exeter
Citation: Prohibiting shark fishing to some extent: study (2020, December 17) retrieved December 17, 2020 from https://phys.org/news/2020-12-shark-fishing-partially-effective.html
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