SCRS SKIPJACK Report 2007
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SCRS SKIPJACK Report 2007
description
SCRS SKIPJACK Report 2007. Baitboat. Purse seiner. Spatial distribution of the SKJ catches during the period (2000-2004) for the main fisheries and fishing gears in the Atlantic ocean. 192.000 t. 137.000 t. 26.000 t. 110.000 t. Eastern Atlantic SKJ. EU purse seiners. FADs. Free school. - PowerPoint PPT Presentation
Transcript of SCRS SKIPJACK Report 2007
SCRS SKIPJACK Report 2007
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Long lineBait boatPurse se ineO ther gears
Spatial distribution of the SKJ catches during the period (2000-2004) for the main fisheries and fishing gears in the Atlantic ocean.
Baitboat
Purse seiner
137.000 t
110.000 t
26.000 t
192.000 t
Eastern Atlantic SKJEU purse seiners
0
2
4
6
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10
1990 1995 2000 2005
tons
/fish
ing
day
YFTSKJBETAll species
Dakar based baitboatsSKJ Standardized CPUE Azores BB
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
1970 1975 1980 1985 1990 1995 2000 2005
Scal
ed C
PUE
(kg/
day-
trip
)
Azorean baitboats
FADs
Freeschool
Eastern Atlantic SKJ
Z = K*( L∞ -L moy) / (L moy - L c)under …. equilibrium conditions
Regular decrease in mean weight (dominated by PS catches) until 1995
and logically regular increase in total mortality (based on Length data) until 1995 ------ but followed by a dramatic decline : moratorium effect ? decrease in fishing effort ?
1970 1980 1990 20000.
51.
01.
52.
02.
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0
Total mortality based on length frequency
Z in
dex
Years
YFT BET SKJ
Western Atlantic SKJ
0,0
1,0
2,0
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5,0
1969 1974 1979 1984 1989 1994 1999 2004
year
kg
BB PS SU
Recent unexplained decline of Venezuelan PS CPUE, while Brasilian BB CPUEs remain “stable”
Different patterns observed for mean weight
But … US LL index increases slowly
Venezuelan PS index decreases continuously, while Brazilian BB index drop only in 2004
Fishery indicators
See you next year for my stock assessment ?
YES, some guys at Corazon de Maria have proposed to evaluate how many skj we are !, how many time we move from the meeting room to the cafeteria, whether the famous FADs in Madrid (i.e., Museo del Jamon, El abuelo, etc) are still attractive for ICCAT scientists …., well you know all types of information very useful for playing with MULTIFAN CL !.
CAUTION! Attending a SKJ assessment meeting is not dangerous and not cause irreversible eye damage
It has been evidenced (by a Bayesian Approach) that the SKJ Rapporteur had to wear glasses BEFORE he started to work with this species.
