market squid lobster abalone rockfish sea urchin shark commercial fishery landings in santa barbara

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