Post on 16-Apr-2017
transcript
GEF International Waters ConferenceSalvador, Brazil20-27 June 2005
APPLICATION OF LME INDICATORS:
SCOTIAN SHELF LME and
THE U.S. NORTHEAST SHELF LME2005-2010
10 U.S. LMEs10 U.S. LMEs
THE SCOTIAN SHELF LME
From: Frank, Petrie, Choi, and Leggett. 2005. Trophic cascades in a formerly cod-dominated ecosystem. Science 308:1621.
CHANGING CONDITIONS
From: Choi, Frank, Leggett, and Drinkwater, 2004. Transition to an alternate state in a continental shelf ecosystem. Can. J. Fish. Aquat. Sci. 61:505-510
NORTHEAST SHELF LME
An undulating oceanographic recorder (above), towed behind a ship, is used to collect ecological parameters needed to assess the state of the marine ecosystem (left).
PRODUCTIVITY INDICATORS
Northeast Shelf Meteorology
Climate Drivers of the Northeast Shelf Ecosystem
• Warm Gulf Stream waters• Cold Scotian Shelf incursions• Winter North American cold air• Warm Gulf of Mexico air• Position of westerly North American jet
air stream
from O. Hertzman, 1996
General Circulation of the Northeast Shelf Ecosystem
FISH AND FISHERIES INDICATORS
• Demersal species surveys• Pelagic species surveys• Ichthyoplankton surveys• Invertebrate surveys (clams, scallops,
shrimp, lobster, squid)• Essential fish habitat• Marine protected areas
COMMON TERMS from Our Living Oceans Report
• Recent average yield (RAY)• Current potential yield (CPY)• Long term potential yield (LTPY)• Stock level relative to LTPY• Status of resource utilization• Threatened or endangered• Potential biological removal (PBR / MMPA)
Figure 6-8. Top - Atlantic herring commercial landings and spawning stock biomass, 1967 through 1996 (thousand metric tons). Bottom - Atlantic mackerel landings and spawning stock biomass, 1963 through 1996 (thousand metric tons).
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19981990198019701966
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Year
Spawning Stock BiomassCommercial Landings
HERRING
3000
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4000
Spaw
ning
Bio
mas
s (m
etric
tons
, 000
s)
Landings (metric tons, 000s)
Year
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19981990198019701962
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MACKEREL
Spaw
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mas
s (m
etric
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, 000
s)
Landings (metric tons, 000s)
Georges Bank Yellowtail
Year1975 1980 1985 1990 1995 2000
Spa
wni
ng S
tock
Bio
mas
s ('0
00 m
t) &
Rec
ruitm
ent (
mill
ions
, age
1)
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Exp
loita
tion
Rat
e
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1.0
Spawning Stock BiomassRecruitmentExploitation Rate
Georges Bank Haddock
Year1975 1980 1985 1990 1995 2000
Spa
wni
ng S
tock
Bio
mas
s ('0
00 m
t) &
Rec
ruitm
ent (
mill
ions
, age
1)
0
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Exp
loita
tion
Rat
e
0.00
0.05
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0.15
0.20
0.25
0.30
0.35
0.40
Spawning Stock BiomassRecruitmentExploitation Rate
1980 1985 1990 1995 20001
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6
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Wei
ght a
t age
, kg
Year
Georges Bank Cod
1965 1970 1975 1980 1985 1990 1995 2000
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Wei
ght a
t age
, kg
Year
Georges Bank Haddock
1975 1980 1985 1990 1995 2000
0.3
0.4
0.5
0.6
0.7
0.8
0.9 Age2 Age3 Age4 Age5
Wei
ght a
t age
, kg
Year
Georges Bank Yellowtail