Despite huge success in reducing
the incidental catch of seabirds in fishing nets, there’s been reports that an
old type of vessel used in South Africa is still posing serious threats to
seabirds.
The Albatross Task Force (ATF)
has been highly successful in achieving a remarkable reduction in the
incidental catch of seabirds in the South African hake trawl fishing industry
through the introduction of bird-scaring lines; a simple and affordable
solution. These lines act as visual deterrents to prevent cable strikes.
Despite these overwhelming
achievements, there is a vessel class of side trawlers which is still posing a
serious threat to seabirds. The side trawlers are some of the oldest vessels in
South Africa’s demersal trawl fishery. These vessels haul catch over the side,
rather than over the stern. The nets are also deployed over the side with the
trawl warps passing through two blocks suspended at the stern. Hence trawl
dragging is actively done from the stern.
Net entanglement is a major
problem when the net stays loose on the sea surface for longer periods, for
example during hauling and setting. Diving birds, mainly Cape Gannets can
become trapped in the mesh of the net. Side trawlers are of special concern
many because of the hauling process where loose net floats for a longer period
compared to that of stern trawlers.
Evidence of this interaction by
South African vessel, was captured on camera by our former Albatross Task Force
leader Barry Watkins on one of his trips however we do yet have a clear idea of
the magnitude of the issue in South Africa.
Currently there are no
particularly successful mitigation measures to reduce the risk of seabirds
becoming entangled in these nets. The current best practice advice suggested by
ACAP (Agreement on the Conservation of Albatrosses and Petrels) is aimed at reducing
the attractiveness of the net to seabirds and limiting the time the net remains
of the water surface.
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