THE SHARK GROUP

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THE SHARK GROUP
EXECUTIVE SUMMARY FOR SHARKS
1- A brief summary of the results achieved
during the Data Preparatory Meeting, Punta
del Este, Uruguay, July 21 to 25
2- Workplan for 2008
3- Recommendations to the Commission (from
the Executive Summary)
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THE SHARK GROUP
1- Data Preparatory Meeting, Punta del Este,
Uruguay, July 21 to 25
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THE SHARK CROWD
Punta del Este, Uruguay, July 2007
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SHARKS
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SHARKS
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SHARKS
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SHARKS
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SHARKS
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SHARKS
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SHARKS
Yearly CPUE (fish per 1,000 hooks), for the blue
shark, from Brazilian longliners operating from
Natal (1986 to 2005) and from five tuna
longliners operating in the Southwestern
Equatorial Atlantic Ocean from May 1958 to
September 1962 .
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THE SHARK GROUP
2- Workplan for 2008
? Blue and mako sharks Full assessment
1- Longfin mako, Isurus paucus 2- Bigeye
thresher, Alopias superciliosus 3- Common
thresher, Alopias vulpinus 4- Oceanic whitetip,
Carcharhinus longimanus 5- Silky shark,
Carcharhinus falciformis 6- Porbeagle, Lamna
nasus 7- Scalloped hammerhead, Sphyrna lewini 8-
Smooth hammerhead, Sphyrna zygaena 9- Crocodile
shark, Pseudocarcharias kamoharai 10- Pelagic
stingray, Pteroplatytrygon violacea

• Rapid assessment of relative vulnerability to
  overfishing,
• based on demographic data and risk analyses,
• and evaluation of their susceptibility to the
  fisheries

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THE SHARK GROUP
2- Workplan for 2008
? Blue and mako sharks Full assessment
Assessment methods to be used a) demographic
model b) bayesian surplus production (BSP)
model c) age-structured production model (ASPM)
incorporating catch data d) catch-free age
structured production model and e) tagging
model an attempt will be made to use the
available tagging data and the historical
longline effort data to provide an independent
estimate of fishing mortality rates (and
associated variances) over time (Aires-da-Silva
et al., 2005). (These estimates could then be
used as priors for the BSP and ASPM models)
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THE SHARK GROUP
3- Management Recommendations (from the
Executive Summary)
a) Before the results of the next assessment
become available next year, on the basis of which
new management recommendations might become
advisable, the Commission should ensure the
effective implementation of Recs. 04-10 and
05-05. Of particular concern is the very low
level of compliance with the obligation of CPCs
to provide Task I and II data for sharks caught
by their vessels, greatly hampering, when not
completely impeding, the assessment of the status
of the exploited shark stocks.
b) For an effective implementation of Rec. 04-10,
the fin to body weight ratio needs to be better
defined in terms of the kind of fins considered
in the ratio as well as the kind of processing of
both fins and body. Conversion factors between
fins and body weights need to be implemented on a
species and/ or fleet-specific basis.
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THE SHARK GROUP
The bottom line What is the great chalenge for
the 2008 assessment ?
Getting updated series of catch and effort data,
and standardized CPUE series from the main
fisheries !!
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THE SHARK GROUP
What are the possible consequences ? Rec.
05-09 As a consequence of these data
deficiencies, increasingly conservative
management measures might be needed to be
implemented by the Commission, in order to limit
the risk of fishery and shark stocks collapse In
the lack of data, the Commission will need to be
precautionarily more pessimistic !!
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