Market Squid

Lobster

Abalone

Rockfish

Sea Urchin

Shark

Commercial Fishery Landings in Santa Barbara

What is Catch??

• Catch = (Catchability) (Effort) (Biomass)

Catchability is f(skill, technology,…)

Effort is hours, # trawls, … = f(profit, …)

Biomass is the stock abundance

• Profit to fishery = (price) (Catch) – (Costs)

Profit drives effort…

Price = f(market, …)

Costs = f(fuel, distance to port, biomass, …)

Fish & Climate

• Several identified oscillators

– annual, SOI & PDO

–more likely as our data sets are short

• Several mechanisms

– changing upwelling – bottom up - food web control

– spawning habitat changes

• The interaction of time scales are key

– If critical time scales are similar, climate is important

Market Squid Landings

VERY short lived – Egg survival is key – Size specific carnivore

Yellowtail Landings

Long lived - Migrates 1000’s km – Eats squid, crabs, sardines

PDOand …

Switching of Alaskan &Wash/Oregon Catches

Related to PDO

Hypothesis: Spawning habitat First feeding

PD

O A

laska

n C

atch

OR

/WA

Catch

Mantua et al paper in reader

Estuaries!

WARM COOL

sardines = warm

anchovies = cool

Varved Sediments in Santa Barbara Basin

• Sediments form in annual varves

• Low O2 – little bioturbation – require C inputs

Fish Abundance from Varves

• Switching between anchovy & sardine

is seen – on 20 to 50 year time scales

• Policy implications are important

– Fishery collapses are not JUST due to

fishing

– Climate control of fish abundances

Fish & Climate

• The interaction of time scales are key

–Salmon its during spawning (precip or first feeding)

– Squid its egg survival & recruitment to adult stages

– Yellowtail its food availability (recruitment?)

– Sardine warm – anchovy cool (food web??)

• If time scales are similar, climate is important

• We know food webs structure changes due to

climate regime shifts

CalCoFIZooplankto

n

Hi Zoo’s = Low Temp

ENSO connection

All in pre-1977

CalCoFI Zooplankton

McGowan et al. [1998] in readings

Food Web

Changes

Zooplankton food web

Association of abundance among taxa

McGowan et al. [1998] in readings

Non ESNO

ESNO

SB Channel – Low Diatoms during 97/98 ENSO

Z(T=10oC)

Chlorophyll

Biogenic Silica - Diatoms

Food Webs & Climate

• Abundances of various components of marine

food web change due to climate

• Some evidence that food webs structure

changes too

– Dominant phytoplankton go from diatoms to mixed

– Zooplankton assemblages & associations change

too

• This alters food webs and the length &

intensity of food chains

Ch

avez

et

al. [

20

03

] p

ap

er

in r

ead

ing

s

Seabirds, Anchovy & Sardine off Peru

Chavez et al. [2003] paper in readings

Seabirds are dominated by a cormorant who lives off anchovy almost exclusively

Seabirds, Anchovy & Sardine off Peru

Sardine Synchrony Over Pacific

The Sardine Regime

The Anchovy Regime

Climate & Fish

• The interaction of time scales are key

– Salmon its during spawning (precip or 1st feeding)

– Squid its egg survival & recruitment to adult stages

– Yellowtail its food availability (recruitment?)

– Sardine warm – anchovy cool (food web??)

• If time scales are similar, climate is important

• We know food webs structure changes due to

climate regime shifts