Shark Depredation and Unwanted Bycatch in Pelagic Longline

Shark Depredation and Unwanted Bycatch in Pelagic Longline Fisheries
most said that they would move out of an area where high catch rates
were experience. Most said that they do this voluntarily when high
catch rates are experienced. One said that he would do nothing to
avoid shark capture. They did not perceive moving to a new area to
be a high cost. Some said that they would avoid shark areas except if
target catch was high.
None of them said that they change their hauling practice to avoid
shark depredation or capture.
No method other than the move-on rule has been tried. One skipper
suggested discarding of offal should only take place once hauling is
complete. In their opinion there are no other methods worth trying.
They mostly felt it would be possible to avoid peak areas and times of
shark abundance. All thought that it is possible to reduce the detection
of baited hooks by sharks by refraining from chumming during the set
and not discarding offal and spent bait during the haul. All felt that you
can’t limit shark access to baited hooks by altering fishing practices to
consider deployment depth of hooks and timing of the soak and haul
to avoid problematic shark species. They don’t think that it’s possible
to deter sharks such as with chemical or electrical deterrents. There
was mixed opinion whether the attractiveness of baited hooks could
be reduced to sharks by using artificial baits, by using light sticks, or
by avoiding a bait type known to result in high shark catch rates. All
thought that you can reduce injury to hooked sharks that you will
discard by using a dehooker. There was mixed opinion whether shark
retention on hooks would be reduced by avoiding a specific size or type
of hook. All thought that you will not reduce the economic impact on
sharks from using a wire leader on branch lines.
A7.12. Incentives and Attitudes on Reducing Shark
Bycatch and Depredation
Most fishermen reported that they do not consider shark bycatch in
South Africa as a threat to the local populations, but they did feel
shark depredation is an issue that needs addressing.
A7.13. Acknowledgements
Thank you to the Western Pacific Regional Fishery Management
Council and especially Eric Gilman for their support, help and
guidance on this project. Thanks too, to Meidad Goren for
undertaking most of the interviews and the observers who collect
the data this report is based upon.
A7.14. References
IUCN Redlist http://www.redlist.org
Lombard AT. 2004. National spatial biodiversity assessment: Marine
component. Department of Environment Affairs and Tourism, 2004.
Marine & Coastal Management 2005. Draft South African National Plan
of Action for the conservation and management of sharks. Marine
and Coastal Management, Department of Environmental Affairs and
Tourism, South Africa. www.environment.gov.za.
Tokyo Report: Report of the 2004 inter-sessional meeting of the ICCAT
sub-committee on bycatches: shark stock assessment. Tokyo, Japan,
14-18 June 2004. www.iccat.es
Most of the Skippers don’t give much of a thought to the issue as
there are no methods known to them. At the end of the day if there is
good fishing and big numbers of sharks the fishing will continue and
the sharks will be discarded, was the general attitude.
There was a lot of variation in the answer to the question of what is
considered the most important factor affecting shark catch rates. The
most common answers included: fishing in colder water, fishing on
topographic features (e.g. banks, shelf break), time of the month (full
moon) and the depth of the hooks (shallower). They all said that they
never fish deliberately to increase their shark catch.
The overwhelming sentiment was that the most practical way of
dealing with the problem would be to leave an area when high catch
rates are experienced.
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