Jesús Jurado-MolinaSchool of Fisheries, University of WashingtonPatricia LivingstonAlaska Fisheries Science Center-NMFS

Fref

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0 5 10 15 20 25Age

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8 COD

GTB

YFS

SOL

HER

ATF

PLK

FABC

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0 5 10 15 20 25

PLK

COD

GTB

YFS

SOL

HER

ATF

Age

PLK - walleye pollock, COD - Pacific cod, GTB - Greenland turbot, YFS - yellowfin sole, SOL - rock sole, HER - Pacific herring

To apply the single and multispecies forecasting models to assess the long-term effects produced by three harvesting regimes (Fref, FABC and F = 0) on yield, total and spawning biomass of some species from the Bering Sea.

Walleye pollock

Pacific cod

Greenland turbot

Yellowfin sole

Rock sole

Pacific herring

Predator-prey Prey

Other predators

Arrowtooth flounder Northern fur seal

)21(

,1,1MMF

tata eNN tatata NFC ,,,

p b

bpbpbpaiofofai NWSBSBS ,,,,,,i a ai

aiaibpaibp BS

NRSM

,

,,,,,,2

BS - suitable prey biomass

S - suitability coefficient of predator i and prey p

R - annual consumption of the predator i

W - weight at age of prey p

M1- residual mortality

M2 - predation mortality

M = M1 + M2 Constant annual consumption of predators. Other food = constant Constant suitability coefficients (from MSVPA) Constant recruitment Recruitment of age-0 individuals takes place in

the third quarter

MeanSuitabilities

Recruitmentassumption

Maturityat age

Bodyweight

Foodconsumption

Initial Nvalues

Yield

FutureF

M2Stock biomass

MSFOR

MSVPA run updated to 1998 data to obtain average suitabilities, average recruitment values and population initial values (1998) for all species.

Three MSFOR runs (Fref, FABC and F = 0) to obtain three equilibrium indicators: yield, total and spawning biomass

Three Single species runs using the same fishing mortalities and obtaining the same indicators

Comparison of the relative change of the indicators using: 100

)(

))()((% x

FI

FIFIIofchange

ref

refABC

W a l l e y e p o l l o c k

0 . 0 E + 0 0

5 . 0 E + 0 7

1 . 0 E + 0 8

1 . 5 E + 0 8

2 . 0 E + 0 8

2 . 5 E + 0 8

3 . 0 E + 0 8

3 . 5 E + 0 8

4 . 0 E + 0 8

1 9 9 0 2 0 0 0 2 0 1 0 2 0 2 0 2 0 3 0 2 0 4 0

F r e f

F A B C

F = 0

P a c i f i c c o d

0 . 0 E + 0 0

5 . 0 E + 0 5

1 . 0 E + 0 6

1 . 5 E + 0 6

2 . 0 E + 0 6

2 . 5 E + 0 6

3 . 0 E + 0 6

3 . 5 E + 0 6

4 . 0 E + 0 6

1 9 9 0 2 0 0 0 2 0 1 0 2 0 2 0 2 0 3 0 2 0 4 0

F r e f

F A B C

F = 0

G r e e n l a n d t u r b o t

0

2 0 0 0 0

4 0 0 0 0

6 0 0 0 0

8 0 0 0 0

1 0 0 0 0 0

1 2 0 0 0 0

1 4 0 0 0 0

1 6 0 0 0 0

1 9 9 0 2 0 0 0 2 0 1 0 2 0 2 0 2 0 3 0 2 0 4 0

F r e f

F A B C

F = 0

Y e l l o w f i n s o l e

0 . 0 E + 0 0

1 . 0 E + 0 7

2 . 0 E + 0 7

3 . 0 E + 0 7

4 . 0 E + 0 7

5 . 0 E + 0 7

6 . 0 E + 0 7

7 . 0 E + 0 7

1 9 9 0 2 0 0 0 2 0 1 0 2 0 2 0 2 0 3 0 2 0 4 0

Y e a r

F r e f

F A B C

F = 0

R o c k s o l e

0

5 0 0 0 0 0 0

1 0 0 0 0 0 0 0

1 5 0 0 0 0 0 0

2 0 0 0 0 0 0 0

2 5 0 0 0 0 0 0

1 9 9 0 2 0 0 0 2 0 1 0 2 0 2 0 2 0 3 0 2 0 4 0

Y e a r

F r e f

F A B C

F = 0

P a c i f i c h e r r i n g

0

5 0 0 0 0 0

1 0 0 0 0 0 0

1 5 0 0 0 0 0

2 0 0 0 0 0 0

2 5 0 0 0 0 0

3 0 0 0 0 0 0

1 9 9 0 2 0 0 0 2 0 1 0 2 0 2 0 2 0 3 0 2 0 4 0

Y e a r

F r e f

F A B C

F = 0

W a lle y e p o llo c k

0

1 0 0 0 0 0 0

2 0 0 0 0 0 0

3 0 0 0 0 0 0

4 0 0 0 0 0 0

5 0 0 0 0 0 0

6 0 0 0 0 0 0

7 0 0 0 0 0 0

1 9 9 0 2 0 0 0 2 0 1 0 2 0 2 0 2 0 3 0 2 0 4 0Y e a r

F re f

F A B C

P a c ific c o d

0

5 0 0 0 0

1 0 0 0 0 0

1 5 0 0 0 0

2 0 0 0 0 0

2 5 0 0 0 0

3 0 0 0 0 0

1 9 9 0 2 0 0 0 2 0 1 0 2 0 2 0 2 0 3 0 2 0 4 0

Y e a r

F re f

F A B C

G re e n la n d tu rb o t

0

2 0 0 0

4 0 0 0

6 0 0 0

8 0 0 0

1 0 0 0 0

1 2 0 0 0

1 4 0 0 0

1 9 9 0 2 0 0 0 2 0 1 0 2 0 2 0 2 0 3 0 2 0 4 0

Y e a r

F re f

F A B C

Y e llo w fin s o le )

0

5 0 0 0 0

1 0 0 0 0 0

1 5 0 0 0 0

2 0 0 0 0 0

2 5 0 0 0 0

3 0 0 0 0 0

3 5 0 0 0 0

4 0 0 0 0 0

4 5 0 0 0 0

1 9 9 0 2 0 0 0 2 0 1 0 2 0 2 0 2 0 3 0 2 0 4 0

Y e a r

F re f

F A B C

ro c k s o le

0

5 0 0 0 0

1 0 0 0 0 0

1 5 0 0 0 0

2 0 0 0 0 0

2 5 0 0 0 0

3 0 0 0 0 0

1 9 9 0 2 0 0 0 2 0 1 0 2 0 2 0 2 0 3 0 2 0 4 0

Y e a r

F re f

F A B C

P a c i f ic h e r r in g

0

5 0 0 0

1 0 0 0 0

1 5 0 0 0

2 0 0 0 0

2 5 0 0 0

1 9 9 0 2 0 0 0 2 0 1 0 2 0 2 0 2 0 3 0 2 0 4 0

Y e a r

F r e f

F A B C

-50

0

50

100

150

200

250

300

350

400

450

plk cod gtb yfs rsol her

MSP

SSP% c

han

ge

MSP- Multispecies forecast, SSP - single species forecast

Proportion of Pacific herring population consumed by predators

Proportion of pollock total population consumed by predators

Predator Fref FABC

Walleye pollock 0.06 0.20Pacific cod 3.80 2.71Greenland turbot 0.005 0.004Arrowtooth flounder 0.20 0.12Total predation 4.07 3.04

Predator Fref FABC

Walleye pollock 12.44 14.71Pacific cod 6.09 5.42Greenland turbot 0.02 0.02Yellowfin sole 0.12 0.10Arrowtooth flounder 8.47 7.32Northern fur seal 1.29 1.06Total predation 28.43 28.62

Multispecies

-50

-40

-30

-20

-10

0

10

20

30

plk cod gtb yfs rsol her atf Biomass

SSB

% c

ha

ng

e

Single species

-50

-40

-30

-20

-10

0

10

20

30

plk cod gtb yfs rsol her atf Biomass

SSB

% c

han

ge

Biomass - total biomass

SSB - spawning biomass

Proportion of rock sole population consumed by predators

Predator Fref F = 0Walleye pollock 0.06 0.40Pacific cod 3.80 4.42Greenland turbot 0.005 0.005Arrowtooth flounder 0.20 0.24Total predation 4.07 5.07

Proportion of pollock population consumed by predators

Predator Fref F = 0Walleye pollock 12.44 15.50Pacific cod 6.09 6.14Greenland turbot 0.02 0.02Yellowfin sole 0.12 0.13Arrowtooth flounder 8.47 8.79Northern fur seal 1.29 1.33Total predation 28.43 31.91

Multispecies

-20

0

20

40

60

80

100

120

plk cod gtb yfs rsol her atf

Biomass

SSB

% c

ha

ng

e

Single species

0

20

40

60

80

100

120

plk cod gtb yfs rsol her atf

Biomass

SSB% change

% c

ha

ng

e

Biomass - total biomassSSB - spawning biomass

SSFOR and MSFOR suggest that the implementation of FABC would produce small long-term changes in the structure of the eastern Bering Sea groundfish populations compared to Fref.

Changes in the F regime can indirectly affect the predation mortality of prey due to decreases in predator population and consumption of prey.

The implementation of the FABC regime resulted in no significant change in pollock predation mortality due to canceling effects of pollock consumption by arrowtooth flounder and adult pollock (cannibalism)

When FABC was implemented, SSFOR and MSFOR predicted almost the same trends for the indicators analyzed. However, some differences in magnitude and direction due to predation interactions were observed for rock sole and Pacific herring.

Multispecies simulations of no fishing scenarios change our perspective on recovery times for depleted populations.

To simulate the system with different levels of recruitment associated to climate shifts

To carry out Monte Carlo simulations for MSFOR and SSFOR incorporating different assumptions on recruitment (Ricker/B&H and stochastic components)

To include the predation equations in a system of linked catch at age models (Multispecies CAGEAN?)