Exploring the ecological and economic role of Pacific sardine

Andrés M. Cisneros-Montemayor and U. Rashid Sumaila

Trinational Sardine Forum. La Jolla, December 8, 2011

Outline

• Fisheries in the California Current• Ecosystem modeling of the BC Shelf• Sardine as a forage fish• Contribution of sardine to ecosystem output• Summary• Next steps and challenges

Fisheries in the California Current

Economic impact of California Current fisheries by country (USD 2011). Landed values are from government statistics (CONAPESCA 2007; DFO 2008; NOAA 2008); economic impact and income effects calculated based on input-output multipliers for fisheries reported in Dyck and Sumaila (2010).

Country Landings(thousands tons)

Landed value(millions USD)

Economic impact

(millions USD)

Income effect(millions USD)

Canada 149 240 794 257

USA 315 503 1,557 652

Mexico 81 70 228 46

Total 545 814 2,581 956

What is the contribution of sardines as forage fish in this system?

Area Theme Species

BC Shelf(Preikshot 2005 )

Ecopath approach 53

Strait of Georgia(Martell et al. 2002)

Ecopath for management

25

Southern BC Shelf(Venier et al. 1996)

Ecopath approach 27

N California Current (WA-OR-CA)(Field et al. 2006)

Climate scenario analysis

63

Current Model (WCVI 3C-3D)

Ecological trends and Fisheries management

33

Ecosystem modeling: BC Shelf

Ecosystem model: BC• 33 functional groups (12 with time-series data);• 10 fishing fleets;• Ecosystem driven by Aleutian Low Pressure Index.

Functional group FleetOrcas POP Eulachon HakeDolphins Shelf rockfish Mesopelagic fish GroundfishBirds Slope rockfish Jellyfish HerringBaleen whales Sablefish Benthos SalmonSteller sea lion Pollock Euphausids SharkHarbor seal Halibut Copepods Small PelagicPelagic sharks Flatfishes Zooplankton SealingSmall sharks Hake Diatoms WhalingSquid Mackerel Large phytoplankton Sardine (dummy)Chinook salmon Sardine Small phytoplanktonCoho salmon Herring Detritus

Ecopath

EcosimEc

osim

Rela

tive

biom

ass

Catc

h(t

hous

ands

of t

ons)

Sardines as forage fish

• Sardine is directly linked (predator/prey) to 19 functional groups;

• Highest average proportion in predator biomass among fish after herring;

• Trophic interactions are confounded with environmental change;

• Model allows us to hold the environment constant;

• Diet matrix and landed values can be used to calculate contribution of sardine to landed values.

Contribution to fisheries value

Total

$4,900,000

Cod-likes$339 K

Scombrids$658 K

Flatfishes$355 K

Salmonids$1.5 M

Sharks$20 K

Rockfishes$1.9 M

Based on Ecopath diet matrix and BC landed value

Pacific Sardine

Contribution to ecosystem output

• Dynamic model: contribution of sardine to species-specific biomass and economic value.

Contribution to ecosystem output

Contribution to ecosystem output

Contribution to ecosystem output

• Total ecosystem fisheries value is currently ~9.2 B USD;

• Including ecosystem effects, the fisheries value of an additional thousand tons of sardine is ~80 K USD.

Summary

• Ecosystem model is providing interesting results, and is closer to adequately representing observed data;

• Sardines contribute significantly to the ecosystem both in terms of production and subsequent fishing value;

• Ecosystem models are not a substitute for stock assessments, but can be used as a testing ground for hypotheses, new methodologies and interdisciplinary research.

Next steps

• Test more hypotheses for environmental drivers and ecosystem shifts;

• Explore mechanisms for sardine population response to environment;

• Validate results with observed fisheries data;

• Expand model to rest of California Current.

Acknowledgements

• J. Schweigert, S. McFarlane, L. Flostrand, J. Detering, J. Lenic, E. Cotero, M. Nevárez and S. Herzka;

• V. Christensen, C. Walters, S. Martell (Committee).

• a.cisneros@fisheries.ubc.ca• andres.cisneros.m@gmail.com• r.sumaila@fisheries.ubc.ca