Kevin T. HillFisheries Resources DivisionSouthwest Fisheries Science Center

Historical overviewSardine population & mgmt since

recoveryStock assessment processAssessment data

Biology, Fisheries, Surveys2010 assessment resultsHarvest policy & management issues

•5-year averages of estimated sardine population biomass, AD 420-1970;•Age-structured estimates shown in red;•Extreme population variability even in absence of fishing;

•periods of peak abundance ~ 50-60 years•link to environmental forcing is assumed

•Typical population dynamic for an ‘R-selected’ species:•small body, rapid growth, early maturation, high fecundity, short generation time, and the ability to disperse offspring widely

Sardine scale-deposition in the Santa Barbara Basin (Soutar & Isaacs 1969; Baumgartner et al. 1992).

“Little Ice Age”

Early Sardine Science & Early Sardine Science & ManagementManagement

Intense fishery sampling, ageing Intense fishery sampling, ageing with scales and otoliths;with scales and otoliths;Catch-effort studies (lunar-month);Catch-effort studies (lunar-month);Tagging studies (still the best Tagging studies (still the best available);available);Early efforts by CDFG biologists to Early efforts by CDFG biologists to set caps and limit reduction set caps and limit reduction fishing;fishing;Agency responses to declining Agency responses to declining catch were mixed & conflicting; catch were mixed & conflicting; ‘‘Marine Research Committee’, Marine Research Committee’, later renamed ‘CalCOFI’, was later renamed ‘CalCOFI’, was established by CA legislature in established by CA legislature in 1949 to ‘study the sardine 1949 to ‘study the sardine problem’;problem’;Actions by the CA legislature were Actions by the CA legislature were too little and too late to avoid too little and too late to avoid eventual moratorium 23 years eventual moratorium 23 years after Monterey fishery collapsedafter Monterey fishery collapsed

0.0051 55 60 65 70 75 80 85 90 95 00 03

0.05

0.10

0.15

0.20

0.25

Decline and Recovery of Sardine

Prop

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itive

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tions

for s

ardi

ne la

rvae

Year

0.0051 55 60 65 70 75 80 85 90 95 00 03

0.05

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0.25

Decline and Recovery of Sardine

Prop

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ardi

ne la

rvae

Year

CalCOFI Sampling

Tagging (1935-1944)

1980s: low abundance,

confined to SCA; minor fisheries in SCA & ENS

1990s: Expansion

offshore and north to Central California;

CCA fishery begins;

Pop’n growth = 33%;

Sardine in OR, WA, and BC

2000s: Fisheries in PNW Seasonal

movements N-S, inshore/offshore

San Pedro

Ensenada

WashingtonOregon

Monterey

British Columbia

2000s

90s

80s

Biology:Age,

Growth, Maturity

Biology:Age,

Growth, Maturity

Fishery:Tonnage, Size & Age

Composition

Fishery:Tonnage, Size & Age

Composition

Abundance:Resource

Survey, CPUE, Age & Size

Composition

Abundance:Resource

Survey, CPUE, Age & Size

Composition

Population Dynamics Model:Birth, Growth, Reproduction, Death

Reconstruct past population trend & productivity. Estimate present

abundancefor resource managers.

Population Dynamics Model:Birth, Growth, Reproduction, Death

Reconstruct past population trend & productivity. Estimate present

abundancefor resource managers.

Stock StatusStock StatusOptimum Yield (socioeconomic and

ecosystem considerations)

Optimum Yield (socioeconomic and

ecosystem considerations)

Fishery Data (tonnage, size, age of removals): Pacific Northwest (PNW) Central California (CCA) Southern California (SCA) Ensenada (ENS)

Fishery-Independent Data (time series of abundance): CDFG & SWFSC egg production surveys:

DEPM or TEP time series, depending on adult sampling; 1985-2010 West Coast Sardine Aerial Survey (industry funded):

Current assessment includes estimates for OR-WA region, 2009 & 2010

Assessment Model: ‘Stock Synthesis’ (Richard Methot, NOAA)

Fully integrated, forward-projecting, length and age-structured, highly flexible

Length-at-age Weight-at-length

Season 1 (Jul-Dec) Season 2 (Jan-Jun)

Season 1

(Jul-Dec)

Season 2

(Jan-Jun)

Low egg density (P0); Spawning fraction ~10% (≤avg); Females slightly larger; SSBtotal = 105,220 mt; SSBfemale = 58,447 mt (0.42); Lowest DEPM biomass estimate

since mid-1990s

DEPM (female SSB)q = 0.1715

TEP (total SSB)q = 0.4568

SS model tuned prior to inclusion of aerial est.;

Catchability fixed to q=1; Length comp fit with dome-shaped

selectivity; Selectivity assumptions not explored

during STAR, but inconsistent with PNW fishery selectivity which is fit to asymptotic shape

173,390 mt (0.4)1,236,910 mt (0.9)

537,173 mt

Independent peer-review (NMFS and PFMC): Stock Assessment Review Panel (4-5 scientists) Scientific and Statistical Committee (~16 scientists) CPS Management Team (agency scientists) CPS Advisory Subpanel (fishing industry & 1 NGO rep)

Management action: Pacific Fishery Management Council (PFMC)

▪ adopt assessment; apply harvest formula; allocate by season/sector

NMFS Southwest Region (SWR)▪ Proposed and final regulations published in Federal Register

Catch monitoring and Enforcement▪ (CDFG, ODFW, WDFW, NOAA)

Season closure (NMFS-SWR)

Stock biomass

(age 1+, mt) Cutoff (mt)Harvest Fraction

U.S. Distribution

U.S. Harvest for 2011 (mt)

537,173 150,000 0.15 0.87 50,526

HG2010 = (BIOMASS2009 – CUTOFF) • FRACTION • DISTRIBUTION

To determine an appropriate (sustainable) FRACTION value:

FMSY = 0.248649805(T2)−8.190043975(T)+67.4558326

where T (oC) is the running average sea-surface temperature at Scripps Pier during the three preceding seasons (July-June), and exploitation FRACTION is bounded between 5% and 15%.Maximum catch allowed = 200,000 mt

Mean three- season SST (°C) at

Scripps

Equilibrium spawning

biomass (mt)

Maximum sustained yield

(MSY)Spawning biomass at

MSY (BMSY) FMSY (%)

16.5 700,000 9 274,000 0.04

17.0 2,700,000 156,000 1,272,000 0.16

17.3 >4,000,000 346,000 1,819,000 0.26

The spawner-recruit model was used to estimate changes in deterministic maximum sustained yield (MSY) reference points due to changes in environmental conditions associated with three-season SST at SIO, with 16.5-17.3° C being the inter-quartile SST range since 1916:

0

100,000

200,000

300,000

400,000

500,000

600,000

700,000

800,00019

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1919

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1925

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1949

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1970

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1982

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2003

2006

Season

Lan

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(mt)

0%

10%

20%

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40%

50%

60%

70%

Har

vest

Rat

e

Landings (mt) Harvest Rate

Sardine will continue to: have rapid fluctuations in abundance/distribution; be utilized by predators, including humans.

Researchers and managers will: have lagged response to changes in the resource; depend on labor-intensive data collection and time

series; require more funding to ‘do it right’

Approach: minimize risk through conservative harvest policies; design surveys & methods applicable to all CPS; strive for international management agreements