status of the southeastern bering sea – upper trophic level and aggregate indicators linking...
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Status of the Southeastern Bering Sea – Upper Trophic Level and Aggregate Indicators
Linking Ecosystem-Based Management Goals with
Ecosystem Research
Fisheries And The
Environment
I. ECOSYSTEM ASSESSMENTObjectives for Ecosystem Protection:
1. Maintain predator-prey relationships a. pelagic forage availabilityb. spatial/temporal conc. of fishery impact on forage fishc. removals of top predatorsd. introduction of non-native species
2. Maintain diversity a. species diversityb. functional (trophic, structural habitat) diversityc. genetic diversity
3. Maintain energy flow and balancea. human-induced energy redirectionb. system impacts attributable to energy removal
CLIMATE and FISHING
20042003200220012000199919981997199619951994199319921991199019891988198719861985198419831982198119801979197819771976197519741973197219711970Year
1995-2003BSPelagic Trawl Duration
1990-2001BS Bottom Trawl Duration
1990-2001AI Bottom Trawl Duration
1993-2002Hook and Line Effort
1982-2003Summer Bottom Temp.
1977-2000FHS (R/S)
1975-1997Rock sole (R/S)
1976-1998ATF (R/S)
1973-1999GT (R/S)
1977-1993Northerns (R/S)
1960-1993POP (R/S)
1964-1998YFS (R/S)
1975-2002RLKI Productivity
1976-2002TBMU Productivity
1975-2002BLKI Productivity
1980-2002Total crab biomass
1982-2003BS Richness
1964-2002Pollock (R/S)
1977-2002Cod (R/S)
1975-1999AK Plaice (R/S)
1982-2003Jellyfish biomass
1982-2003BS Diversity
1982-2003Total CPUE
1977-2000Atka (R/S)
1951-2004AOI
1976-2002COMU Productivity
1970-2004May SST
1978-2004Herring recruits
1901-2004PDO
1900-2003Total salmon catch
1916-2004Surface Winter Air Temp.
1962-2003AI Trophic level of catch
1954-2004Ice Cover Index
1954-2003BS Trophic level of catch
20042003200220012000199919981997199619951994199319921991199019891988198719861985198419831982198119801979197819771976197519741973197219711970Year
1995-2003BSPelagic Trawl Duration
1990-2001BS Bottom Trawl Duration
1990-2001AI Bottom Trawl Duration
1993-2002Hook and Line Effort
1982-2003Summer Bottom Temp.
1977-2000FHS (R/S)
1975-1997Rock sole (R/S)
1976-1998ATF (R/S)
1973-1999GT (R/S)
1977-1993Northerns (R/S)
1960-1993POP (R/S)
1964-1998YFS (R/S)
1975-2002RLKI Productivity
1976-2002TBMU Productivity
1975-2002BLKI Productivity
1980-2002Total crab biomass
1982-2003BS Richness
1964-2002Pollock (R/S)
1977-2002Cod (R/S)
1975-1999AK Plaice (R/S)
1982-2003Jellyfish biomass
1982-2003BS Diversity
1982-2003Total CPUE
1977-2000Atka (R/S)
1951-2004AOI
1976-2002COMU Productivity
1970-2004May SST
1978-2004Herring recruits
1901-2004PDO
1900-2003Total salmon catch
1916-2004Surface Winter Air Temp.
1962-2003AI Trophic level of catch
1954-2004Ice Cover Index
1954-2003BS Trophic level of catch
Bering Sea/Aleutian Islands
1995
2000
1990
1985
1980
1975
1970 Legend
X>2.6
2.6>X>1.6
1.6>X>0.5
0.5>X>-0.5
-0.5>X>-1.6
-1.6>X>-2.7
no data
BS Pelagic Trawl DurationBS Bottom Trawl DurationAI Bottom Trawl Duration
Hook and Line Effort
Summer Bottom Temp.FHS (R/S)
Rock sole (R/S)
ATF (R/S)GT (R/S)
Northerns (R/S)POP (R/S)YFS (R/S)
RLKI ProductivityTBMU ProductivityBLKI Productivity
Total crab biomassBS RichnessPollock (R/S)
Cod (R/S)AK Plaice (R/S)
Jellyfish biomassBS Diversity
Total CPUEAtka (R/S)
AOI COMU Productivity
May SSTHerring recruits
PDOTotal salmon catch
Surf. Winter Air Temp.AI Trophic levelIce Cover Index
BS Trophic level
Objectives for Ecosystem Protection:
1. Maintain predator-prey relationships by examining:a. pelagic forage availabilityb. spatial/temporal conc. of fishery impact on forage fishc. removals of top predatorsd. introduction of non-native species
2. Maintain diversity by examining: a. species diversityb. functional (trophic, structural habitat) diversityc. genetic diversity
3. Maintain energy flow and balance by examining:a. human-induced energy redirectionb. system impacts attributable to energy removal
Objectives for Ecosystem Protection:
1. Maintain predator-prey relationships by examining:a. pelagic forage availability
Significance threshold: changes outside natural variability for prey relative to predator demands
Indicators:-NMFS bottom trawl survey catches of forage fish-BASIS surveys -age-0 pollock (BS) -ADFG herring-Groundfish trends-Groundfish fishery bycatch amounts-Bristol Bay sockeye salmon
Eulachon
0
10
20
30
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
Capelin
0
20
40
60
80
100
120
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
FORAGE –NMFS (Lauth)
0
1000
20001
978
198
3
198
8
199
3
199
8
200
3
0
200
400
AbundanceAge-4 recruits
BiomassCatch
Ab
un
dan
ce &
Rec
ruit
s (m
illio
ns
fish
)
FORAGE –Togiak Herring (F. West)
Bio
mas
s an
d C
atch
(1,
000s
mt)
JuvenileSockeyeCounts
2000 2001 2002 2003 2004
Age-0PollockCounts
FORAGE – Juvenile sockeye and pollock-BASIS (Eisner et al.)
Bristol Bay Sockeye Salmon (L. Fair)
0
10
20
30
40
50
60
7019
56
1961
1966
1971
1976
1981
1986
1991
1996
2001
Ca
tch
plu
s e
sca
pe
me
nt
(mill
ion
s)
OtherUgashik
Naknek
KvichakEgegik
POLLOCK
-0.20
-0.10
0.00
0.10
0.20
0.30
COD
-0.20
0.00
0.20
0.40
0.60
GT
-0.20
0.00
0.20
0.40
ATF
-0.20
-0.10
0.00
0.10
0.20
ROCK SOLE
-0.40
-0.20
0.00
0.20 NORTHERNS
-0.10
0.00
0.10
0.20
YFS
-0.20
0.00
0.20
0.40
1960
1966
1972
1978
1984
1990
1996
2002
FH SOLE
-0.40
-0.20
0.00
0.20
0.40
1960
1966
1972
1978
1984
1990
1996
2002
POP
-0.40
-0.20
0.00
0.20
0.40
1960
1966
1972
1978
1984
1990
1996
2002
AI ATKA
-0.10
0.00
0.10
0.20
0.30
1960
1966
1972
1978
1984
1990
1996
2002
1976/77 shift 1988/89 shift Other shift
AK PLAICE
-0.50
0.00
0.50
1.00
1960
1966
1972
1978
1984
1990
1996
2002
R/S
A
nom
alies
B.Sea
Groundfish
-0.5
0.0
0.5
1.0
19
70
19
72
19
74
19
76
19
78
19
80
19
82
19
84
19
86
19
88
19
90
19
92
19
94
19
96
19
98
20
00
20
02 -1
.0-0
.50
.00
.51
.0
19
70
19
72
19
74
19
76
19
78
19
80
19
82
19
84
19
86
19
88
19
90
19
92
19
94
19
96
19
98
20
00
20
02
-0.5
0.0
0.5
19
70
19
72
19
74
19
76
19
78
19
80
19
82
19
84
19
86
19
88
19
90
19
92
19
94
19
96
19
98
20
00
20
02
-1.0
-0.5
0.0
0.5
1.0
19
70
19
72
19
74
19
76
19
78
19
80
19
82
19
84
19
86
19
88
19
90
19
92
19
94
19
96
19
98
20
00
Bering Sea Gulf of Alaska
Su
rviv
al R
ate
Ind
ex
Re
cru
itmen
t In
de
xS
urv
iva
l Ra
te In
de
x
Re
cru
itmen
t In
de
x
-0.5
0.0
0.5
1.0
19
70
19
72
19
74
19
76
19
78
19
80
19
82
19
84
19
86
19
88
19
90
19
92
19
94
19
96
19
98
20
00
20
02 -1
.0-0
.50
.00
.51
.0
19
70
19
72
19
74
19
76
19
78
19
80
19
82
19
84
19
86
19
88
19
90
19
92
19
94
19
96
19
98
20
00
20
02
-0.5
0.0
0.5
19
70
19
72
19
74
19
76
19
78
19
80
19
82
19
84
19
86
19
88
19
90
19
92
19
94
19
96
19
98
20
00
20
02
-1.0
-0.5
0.0
0.5
1.0
19
70
19
72
19
74
19
76
19
78
19
80
19
82
19
84
19
86
19
88
19
90
19
92
19
94
19
96
19
98
20
00
Bering Sea Gulf of Alaska
Su
rviv
al R
ate
Ind
ex
Re
cru
itmen
t In
de
xS
urv
iva
l Ra
te In
de
x
Re
cru
itmen
t In
de
x
Groundfish – Combined Std. Indices of Recruitment and Survival (Mueter)
Biological Response to Climate Flatfish Distribution-(Spencer)
Objectives for Ecosystem Protection:
1. Maintain predator-prey relationships by examining:a. pelagic forage availabilityb. spatial/temporal conc. of fishery impact on forage fishc. removals of top predatorsd. introduction of non-native species
2. Maintain diversity by examining: a. species diversityb. functional (trophic, structural habitat) diversityc. genetic diversity
3. Maintain energy flow and balance by examining:a. human-induced energy redirectionb. system impacts attributable to energy removal
Objectives for Ecosystem Protection:
1. Maintain predator-prey relationships by examining:a. pelagic forage availabilityb. spatial/temporal conc. of fishery impact on forage fishc. removals of top predatorsd. introduction of non-native species
2. Maintain diversity by examining: a. species diversityb. functional (trophic, structural habitat) diversityc. genetic diversity
3. Maintain energy flow and balance by examining:a. human-induced energy redirectionb. system impacts attributable to energy removal
Significance threshold: catches high enough to cause biomass of top predator(s) to fall below min. biol. acceptable limits
Indicators:-Trophic level of the catch
-Population status of top predators-Fishing takes of top predators-Seabird incidental take
To
tal
catc
h (
1000
t) 4
0
1,000
2,000
1
2
3
Tro
ph
ic l
evel
cat
ch
0.0
1.0
2.0
3.0
FIB
Ind
ex
1960
1970
1980
1990
2000
1960
1970
1980
1990
2000
TOP PREDATORS – Trophic level of the catch
FIB= index that shows a decline in TL only when catches do not
increase as expected
•Northern fur seal pup production continued decline (Sinclair et al.)
Pu
ps
bo
rn (
1,0
00
's)
St. George
10
20
30
40
50
73 78 83 88 93 98 03
St. Paul
125
175
225
275
325
73 78 83 88 93 98 03
TOP PREDATORS
TOP PREDATORS – Seabirds (Fitzgerald et al.)
Seabird Breeding Chronology
0
2
4
6
8
10
12>3days earlier than average
=within 3days of average
>3 days later than average
Fre
qu
ency
N.BS/Chuk. SE BS SW BS GOA SEAK
Seabird Population Trends
024681012141618 Negative trend
No discernable trend
Positive trend
Fre
qu
ency
N.BS/Chuk. SE BS SW BS GOA SEAK
Seabird Productivity Levels
0
2
4
6
8
10
12
14
16>20% below average
Within 20% of average
>20% above average
Fre
qu
ency
N.BS/Chuk. SE BS SW BS GOA SEAK
Fis
hin
g E
ffo
rt (
in 1
,000
's o
f h
oo
ks)
Inci
den
tal t
ake
rate
(p
er 1
,000
ho
oks
)
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
BSAI
0.10
50,000
100,000
150,000
200,000
250,000
300,000
0
0.04
0.08
0.12
0.16
0.2
Effort Incidental take
TOP PREDATORSSeabird Incidental Take (Fitzgerald et al.)
0
50,000
100,000
150,000
200,000
250,000
300,000
350,000
400,000
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
Bio
mas
s (t
)
PREDATOR -Bering Sea Jellyfish (Walters)
Objectives for Ecosystem Protection:
1. Maintain predator-prey relationships by examining:a. pelagic forage availabilityb. spatial/temporal conc. of fishery impact on forage fishc. removals of top predatorsd. introduction of non-native species
2. Maintain diversity by examining: a. species diversityb. functional (trophic, structural habitat) diversityc. genetic diversity
3. Maintain energy flow and balance by examining:a. human-induced energy redirectionb. system impacts attributable to energy removal
Objectives for Ecosystem Protection: Maintain predator-prey relationships by examining:
pelagic forage availability spatial/temporal conc. of fishery impact on forage fish removals of top predators introduction of non-native species
2. Maintain diversity by examining: a. species diversity
Significance threshold: catch high enough to cause biomass to fall below or be kept from recovering from min. biol. acceptable limits
Indicators:-Status of protected and managed stocks relative to thresholds-Species richness and diversity-Areas closed to fishing-Pop’n trends -other nontarget species from surveys (eg.
eelpouts)-Bycatch trends of sensitive species lacking population estimates
Ecosystem Mngt Info. –Area closures (Coon)
Spe
cies
per
hau
l
1985 1990 1995 2000
1213
1415
Spe
cies
per
hau
l
1985 1990 1995 2000
1.6
1.8
2.0
SPECIES DIVERSITY –
Species richness and diversity (Mueter)
Sha
nnon
-Wie
ner
inde
xRichness= number of species per haul Diversity= function of number of
species and relative abundance per haul
Objectives for Ecosystem Protection:
1. Maintain predator-prey relationships by examining:a. pelagic forage availabilityb. spatial/temporal conc. of fishery impact on forage fishc. removals of top predatorsd. introduction of non-native species
2. Maintain diversity by examining: a. species diversityb. functional (trophic, structural habitat) diversityc. genetic diversity
3. Maintain energy flow and balance by examining:a. human-induced energy redirectionb. system impacts attributable to energy removal
Objectives for Ecosystem Protection:
2. Maintain diversity by examining: b. Functional (trophic and structural habitat) diversity
Significance threshold: catch high enough to cause change outside observed natural variability
Indicators:-guild or size diversity-bottom gear effort-HAPC biota bycatch-habitat research:
Distribution of deep-water corals in AISeafloor mapping and colonization studiesEffects of trawling on benthic habitatGrowth and recruitment of coralSpatial and temporal patterns in BS invertebrate
assemblages
3.16
3.65
3.98
4.23
4.42
1982 19
84 1986 19
88 1990 19
92 1994 1996 1998 2000
20020
1
2
3
4
5
6
7
8
9
10
11
12
ln (N +1)
ln (length midpoint +1)
Year
aa
Demersal fish community size spectrum, 1982-2002 (Bartkiw et al.)
Through time:
fewer small individuals and
more large individuals
0
500
1000
1500
2000
2500
3000
3500
1990 1992 1994 1996 1998 2000 2002 2004Ob
serv
ed B
ott
om
Tra
wl d
ura
tio
n (
24 h
ou
r d
ays)
GOAAI
BS
SPECIES DIVERSITY- Bottom trawl effort (Coon)
Seapens
0
5
10
15
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
Sea anemone
0
100
200
300
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
Sponge
0
500
1000
1500
2000
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
FUNCTIONAL DIVERSITY – HAPC Biota (Lauth)
Objectives for Ecosystem Protection:
1. Maintain predator-prey relationships by examining:a. pelagic forage availabilityb. spatial/temporal conc. of fishery impact on forage fishc. removals of top predatorsd. introduction of non-native species
2. Maintain diversity by examining: a. species diversityb. functional (trophic, structural habitat) diversityc. genetic diversity
3. Maintain energy flow and balance by examining:a. human-induced energy redirectionb. system impacts attributable to energy removal
Objectives for Ecosystem Protection:
3. Maintain energy flow and balance by examining:a. human-induced energy redirection
Significance threshold: long-term changes in system biomass, respiration, production, energy-cycling due to discards and offal
Indicators:-Prohibited species bycatch amounts-Nontarget catch and discards-Groundfish discards-Trends in scavenger species
ENERGY REDIRECTIONProhibited Catch (Hiatt and Terry)
0
5000
10000
15000
No.
of
crab
(10
00s) BAIRDI CRAB
OTHER TANNER CRAB
0
100
200
300
400
No.
fis
h (1
000s
)
CHINOOK SALMONOTHER SALMON
0
100
200
300
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
No.
of
crab
(10
00s)
RED KING CRABOTHER KING CRAB
0
2000
4000
6000
8000
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
Met
ric
tons
HALIBUT MORTALITYHERRING BYCATCH
ENERGY REDIRECTIONDiscards (Hiatt and Terry)
Bering Sea/Aleutian Islands
0
100
200
30019
94
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
0%
4%
8%
12%
16%
Dis
card
s (1
000
t)
Dis
card
rat
e
Tonnage discardedPercent discarded
Improved retention regulations
Objectives for Ecosystem Protection:
1. Maintain predator-prey relationships by examining:a. pelagic forage availabilityb. spatial/temporal conc. of fishery impact on forage fishc. removals of top predatorsd. introduction of non-native species
2. Maintain diversity by examining: a. species diversityb. functional (trophic, structural habitat) diversityc. genetic diversity
3. Maintain energy flow and balance by examining:a. human-induced energy redirectionb. system impacts attributable to energy removal
Objectives for Ecosystem Protection:
3. Maintain energy flow and balance by examining:b. system impacts attributable to energy removal
Significance threshold: long-term changes in system biomass, respiration, production, energy-cycling due to fishery removals of energy
Indicators:-Total catch relative to production
Eastern Bering Sea Catch
-
500,000
1,000,000
1,500,000
2,000,000
2,500,000
1954 1959 1964 1969 1974 1979 1984 1989 1994 1999Year
Ca
tch
(m
t)
Other species
Crab
Flatfish
Pacific herring
Rockfish
Pacific cod
Walleye pollock
ENERGY REMOVAL -Total Catch
0
200
400
600
800
1000
1200
1400
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
BS
AS
P (
1000
mt)
0
50
100
150
200
250
300
GO
A A
SP
(10
00 m
t)
Bering SeaGulf of Alaska
-10000
1000200030004000500060007000
AS
P (
1000
mt)
ENERGY REMOVAL– ASP (Mueter)
Groundfish FMP Goals
• Prevent overfishing
• Promote sustainable fisheries and communities
• Preserve food web
• Manage incidental catch and reduce bycatch and waste
• Avoid impacts to seabirds and marine mammals
• Reduce and avoid impacts to habitat
• Promote equitable and efficient use of fishery resources
• Increase Alaska native consultation
• Improve data quality, monitoring and enforcement
Management GoalsEcosystem Assessment
Objectives• Maintain predator-prey
relationships
• Maintain diversity
• Maintain energy flow and balance
Groundfish FMP Goals
Prevent overfishing
Promote sustainable fisheries and communities
Preserve food web
Manage incidental catch and reduce bycatch and waste
Avoid impacts to seabirds and marine mammals
Reduce and avoid impacts to habitat
Promote equitable and efficient use of fishery resources
Increase Alaska native consultation
Improve data quality, monitoring and enforcement
Ecosystem Considerations Indices
Status of stocks, annual surplus productivity
Fishing overcapacity programs
Pelagic forage availability, spatial/temporal conc. of fishery impact on forage fish, removals of top predators, introduction of non-native species
Prohibited species, discards, bycatch, scavenger population trends
Seabird and mammal incidental take, population abundance, productivity, and chronology trends
EFH research, effects of fishing gear on habitat research
Fishing overcapacity programs, groundfish fleet composition
ANTEK of climate regimes
Executive Summary• CLIMATE
– North Pacific in uncertain state – BS continues to warm, less sea ice and earlier retreat
• BIOLOGY– BS summer zooplankton biomass: low 2000-2004– BS jellyfish biomass: low 2000-2004– Warming trend may affect flatfish distribution– Most seabirds show no discernable population trend– 2002 seabird breeding chronology was early– 2004 N. fur seal pups born continued to decline– ASP in BS decreased from 1978-2004
• FISHERY EFFECTS– 2003 and 2004 increases in herring and other salmon
bycatch– 2003 seabird incidental take rate same as 2002
Website: Geoff Langhttp://access.afsc.noaa.gov/reem/ecoweb/index.cfm
Summary• No noted significant adverse impacts of fishing on
the ecosystem (relating to predator/prey interactions, energy flow/removal, or diversity).
• There are gaps in understanding the system-level impacts and spatial/temporal effects of fishing on community structure and prey availability.
• Future: incorporate predictions from multispecies models.
• Need research, validation of models, and models focused on understanding spatial processes, and improvements in monitoring systems
• A range of possible climate scenarios and plausible effects on recruitment should be entertained.