Commercial Fishery Landings in Santa Barbara Abalone Shark Sea Urchin Market Squid Rockfish Lobster

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 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

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

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

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

CalCoFI Zooplankton Hi Zoo’s = Low Temp ENSO connection All in pre-1977

CalCoFI Zooplankton McGowan et al. [1998] in readings

Food Web Changes Non ESNO ESNO Zooplankton food web Association of abundance among taxa McGowan et al. [1998] in readings

Z(T=10oC) Chlorophyll Biogenic Silica - Diatoms SB Channel – Low Diatoms during 97/98 ENSO

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

Chavez et al. [2003] paper in readings

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