Shark Depredation and Unwanted Bycatch in Pelagic Longline

Shark Depredation and Unwanted Bycatch in Pelagic Longline Fisheries
Table A6.4. Catch rates during the mahi mahi season in the port of Ilo,
2005-2006 (Pro Delphinus, unpublished data).
Year
CPUE (number per 1000 hooks)
Mahi Mahi Blue Shark Mako Shark
2005 94.15 0.0 0.0
2006 95.69 0.65 0.0
Table A6.5. Catch composition, by weight and value, for the port of Ilo,
2003-2006 (Pro Delphinus, unpublished data).
Species Catch (x 1,000 kg) Revenue ($1000US)
Mahi mahi 74.247 95.036
Blue sharks 1.275 1.148
Mako sharks 0.817 1.511
Swordfish 0.106 0.248
Table A6.6. Number caught and disposition of sharks in Ilo and Salaverry longline fisheries (Pro Delphinus, unpublished data).
Year
No. sharks
caught
No. sharks
discarded
No. sharks
finned
No. whole sharks
retained
Percent sharks
retained
(any part of
individual shark
is retained)
Percent sharks
finned
2004-2005 139 8 0 129 93 0
2005-2006 27 1 0 26 96 0
Table A6.7. Number of sharks by individual species caught, proportion that are dead when hauled to the vessel, CPUE, number discarded alive,
number discarded dead and number of whole sharks retained by the Peruvian longline mahi mahi fleet (Pro Delphinus, unpublished data)
Shark species Number caught Number dead
when hauled to
the vessel
CPUE
(number caught
per 1000 hooks)
Number
discarded alive
Number
discarded dead
Number whole
sharks (carcass
plus other parts)
landed
Blue 108 4 0.5669 3 0 99
Mako 45 9 0.2362 5 0 35
Ray 22 0 0.1155 21 0 1
Hammerhead 4 3 0.0210 0 0 4
Other 9 8 0.0472 1 0 7
A6.4. Catch and Discard Rates of Target
and Bycatch Species
A summary of catch rates for the Peruvian artisanal longline fleet
in the port of Ilo during the summer mahi mahi season of 2005 and
2006 is presented in Table A6.4. Catch rates shown are for all caught
fish (both retained and discarded).
Pro Delphinus onboard observers also collected data on catch
composition for the port of Ilo. Table A6.5 presents catch composition
data obtained from 35 observed trips during mahi mahi seasons from
2003 to 2006. During the 2005 mahi mahi season almost all sharks
captured were retained and landed. Sharks were processed for both
their fins and meat. Some rays were discarded, particularly in the
port of Ilo, where they have no commercial value. In a few cases, small
(below 60 cm in length) individual blue sharks were also released
alive. From 2004 to 2006 Pro Delphinus onboard observers monitored
in detail the shark take during mahi mahi season in 4 ports for a total
of 27 trips and 197 sets. Information on capture rates by species and
fate of caught animals is presented in Tables A6.6 and A6.7.
A6.5. Regulations and their Implications
for a Management Framework
In Peru there is a target fishery for sharks, which operates about 9
months of each year. Sharks are typically retained as an incidental
catch during the other three months of the year when the fleet
targets mahi mahi. There are regulations setting the minimum size
of capture for some species such as the coastal smoothounds from
the genus Mustelus and Triakis, as well as for blue sharks, makos and
hammerheads sharks. There is, however, little or no enforcement of
these regulations.
Peru has no specific shark finning regulations. There is no apparent
need for such regulations because both shark meat and fins are utilized
and commercialized. Animals are typically retained and finned
either onboard or at the port. The high number of shark landings and
demand from the domestic market (Estrella and Guevara-Carrasco,
1998a, 1998b; Estrella et al. 1998, 1999 and 2000) as well as the
international market for shark meat and fins (PROMPEX Peru, 2006)
may help explain why shark finning does not occur in Peru.
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