Status of the Southeastern Bering Sea - PICES workshop... · Status of the Southeastern Bering Sea – Upper Trophic Level and Aggregate Indicators Linking Ecosystem-Based Management

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 diversitya. 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

199BSPelagic Trawl Duration

199BS Bottom Trawl Duration

199AI Bottom Trawl Duration

199Hook and Line Effort

198Summer Bottom Temp.

197FHS (R/S)

197Rock sole (R/S)

197ATF (R/S)

197GT (R/S)

197Northerns (R/S)

196POP (R/S)

196YFS (R/S)

197RLKI Productivity

197TBMU Productivity

197BLKI Productivity

198Total crab biomass

198BS Richness

196Pollock (R/S)

197Cod (R/S)

197AK Plaice (R/S)

198Jellyfish biomass

198BS Diversity

198Total CPUE

197Atka (R/S)

195AOI

197COMU Productivity

197May SST

197Herring recruits

190PDO

190Total salmon catch

191Surface Winter Air Temp.

196AI Trophic level of catch

195Ice Cover Index

195BS Trophic level of catch

20042003200220012000199919981997199619951994199319921991199019891988198719861985198419831982198119801979197819771976197519741973197219711970Year

199BSPelagic Trawl Duration

199BS Bottom Trawl Duration

199AI Bottom Trawl Duration

199Hook and Line Effort

198Summer Bottom Temp.

197FHS (R/S)

197Rock sole (R/S)

197ATF (R/S)

197GT (R/S)

197Northerns (R/S)

196POP (R/S)

196YFS (R/S)

197RLKI Productivity

197TBMU Productivity

197BLKI Productivity

198Total crab biomass

198BS Richness

196Pollock (R/S)

197Cod (R/S)

197AK Plaice (R/S)

198Jellyfish biomass

198BS Diversity

198Total CPUE

197Atka (R/S)

195AOI

197COMU Productivity

197May SST

197Herring recruits

190PDO

190Total salmon catch

191Surface Winter Air Temp.

196AI Trophic level of catch

195Ice Cover Index

195BS 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 EffortSummer 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


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

020406080

100120

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

2004

2006

FORAGE –NMFS (Lauth)

0

1000

200019

78

1983

1988

1993

1998

2003

0

200

400AbundanceAge-4 recruits

BiomassCatch

Abu

ndan

ce &

Rec

ruits

(mill

ions

fish

)

Bio

mas

s an

d C

atch

(1,0

00s

mt)

FORAGE –Togiak Herring (F. West)

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

2001Cat

ch p

lus

esca

pem

ent (

milli

ons) Other

UgashikNaknekKvichakEgegik

POLLOCK

-0.20-0.100.000.100.200.30

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

An

omal

ies

Groundfish B.Sea

-0.5

0.0

0.5

1.0

1970

1972

1974

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

-1.0

-0.5

0.0

0.5

1.0

1970

1972

1974

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

-0.5

0.0

0.5

1970

1972

1974

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

-1.0

-0.5

0.0

0.5

1.0

1970

1972

1974

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

Bering Sea Gulf of AlaskaS

urvi

val R

ate

Inde

x

Rec

ruitm

ent I

ndex

Sur

viva

l Rat

e In

dex

Rec

ruitm

ent I

ndex

-0.5

0.0

0.5

1.0

1970

1972

1974

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

-1.0

-0.5

0.0

0.5

1.0

1970

1972

1974

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

-0.5

0.0

0.5

1970

1972

1974

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

-1.0

-0.5

0.0

0.5

1.0

1970

1972

1974

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

Bering Sea Gulf of AlaskaS

urvi

val R

ate

Inde

x

Rec

ruitm

ent I

ndex

Sur

viva

l Rat

e In

dex

Rec

ruitm

ent I

ndex

Groundfish – Combined Std. Indices of Recruitment and Survival (Mueter)

Biological Response to Climate Flatfish Distribution-(Spencer)









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

Tota

l cat

ch (1

000

t) 4

0

1,000

2,000

1

2

3

Trop

hic

leve

l cat

ch

0.0

1.0

2.0

3.0

FIB

Inde

x

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.)

Pups

bor

n (1

,000

'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

Freq

uenc

y

N.BS/Chuk. SE BS SW BS GOA SEAK

Seabird Population Trends

024681012141618 Negative trend

No discernable trend

Positive trend

Freq

uenc

y


Seabird Productivity Levels

0

2

4

6

8

10

12

14

16>20% below average

Within 20% of average

>20% above average

Freq

uenc

y


Fish

ing

Effo

rt(in

1,0

00's

of h

ooks

)

Inci

dent

al ta

ke ra

te (

per 1

,000

hoo

ks)

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:Maintain predator-prey relationships by examining:

pelagic forage availabilityspatial/temporal conc. of fishery impact on forage fishremovals of top predatorsintroduction 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. acceptablelimits

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)

Shan

non-

Wie

ner i

ndex

Richness= number of species per haul Diversity= function of number of species and relative abundance per

haul






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

123456789

101112

ln (N +1)

ln (length midpoint +1)

Year

aa

Through time:

fewer small individuals and

more large individuals

Demersal fish community size spectrum, 1982-2002 (Bartkiw et al.)

0

500

1000

1500

2000

2500

3000

3500

1990 1992 1994 1996 1998 2000 2002 2004Obs

erve

d B

otto

m T

raw

l dur

atio

n (2

4 ho

ur 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: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 c

rab

(100

0s) BAIRDI CRAB

OTHER TANNER CRAB

0

100

200

300

400

No.

fish

(100

0s)

CHINOOK SALMONOTHER SALMON

0

100

200

300

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

No.

of c

rab

(100

0s)

RED KING CRABOTHER KING CRAB

0

2000

4000

6000

8000

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

Met

ric to

ns

HALIBUT MORTALITYHERRING BYCATCH

ENERGY REDIRECTIONDiscards (Hiatt and Terry)

Bering Sea/Aleutian Islands

0

100

200

30019

9419

9519

9619

9719

9819

9920

0020

0120

0220

0320

04

0%

4%

8%

12%

16%

Dis

card

s (10

00 t)

Dis

card

rat

e

Tonnage discardedPercent discarded

Improved retention regulations






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

Cat

ch (m

t)

Other species

Crab

Flatfish

Pacific herring

Rockfish

Pacific cod

Walleye pollock

ENERGY REMOVAL -Total Catch

0

200400600800100012001400

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

2004

BS

ASP

(100

0 m

t)

0

50

100

150

200

250

300

GO

A A

SP (1

000

mt)

Bering SeaGulf of Alaska

-10000

1000200030004000500060007000

ASP

(100

0 m

t)

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 multispeciesmodels.

• 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.

Documents

Status of the Southeastern Bering Sea - PICES workshop... · Status of the Southeastern Bering Sea – Upper Trophic Level and Aggregate Indicators Linking Ecosystem-Based Management