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
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