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Commercial Fishery Landings in Santa Barbara
Abalone Shark Sea Urchin Market Squid Rockfish Lobster
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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, …)
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Fish & Climate Several identified oscillators Several mechanisms
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
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Market Squid Landings VERY short lived – Egg survival is key – Size specific carnivore
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Yellowtail Landings Long lived - Migrates 1000’s km – Eats squid, crabs, sardines
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PDO and … PDO Alaskan Catch OR/WA Catch Switching of Alaskan &
Wash/Oregon Catches Related to PDO Hypothesis: Spawning habitat First feeding PDO Alaskan Catch OR/WA Catch Mantua et al paper in reader
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Estuaries!
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WARM COOL sardines = warm anchovies = cool
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Varved Sediments in Santa Barbara Basin
Sediments form in annual varves Low O2 – little bioturbation – require C inputs
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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
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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
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CalCoFI Zooplankton Hi Zoo’s = Low Temp ENSO connection
All in pre-1977
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CalCoFI Zooplankton McGowan et al. [1998] in readings
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Food Web Changes Non ESNO ESNO Zooplankton food web
Association of abundance among taxa McGowan et al. [1998] in readings
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Z(T=10oC) Chlorophyll Biogenic Silica - Diatoms SB Channel – Low Diatoms during 97/98 ENSO
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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
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Chavez et al. [2003] paper in readings
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Seabirds, Anchovy & Sardine off Peru
Chavez et al. [2003] paper in readings
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Seabirds are dominated by a cormorant who lives off anchovy
almost exclusively
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Seabirds, Anchovy & Sardine off Peru
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Sardine Synchrony Over Pacific
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The Sardine Regime
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The Anchovy Regime
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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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