Megan Stachura and Nathan Mantua University of Washington School of Aquatic and Fishery Sciences September 8, 2012

Synchrony in the Northeast Pacific Synchrony of biological time series Ecosystem regime shifts Correspond with climatic shifts Leading principal component scores from principal component analysis of 69 North Pacific biological time series (Hare and Mantua, 2000)

Common patterns of variability Positive correlation within groundfish taxonomic group and region, negative between (Hollowed et al. 1987, Mueter et al. 2007) Grouping based on life history (Spencer and Collie, 1997) BSAI groundfish stock-recruit residuals and cluster dendogram based on these (Mueter et al., 2007)

Hypothesis Organisms with related life history and habitat characteristics will show similar exposure to environmental variables and exhibit common patterns of recruitment/abundance

Data Recruitment Number of fish surviving to enter the fishery or some specified age We have survey and fishing data of adult stages but don’t know a lot about what happens during early life Age of recruitment varies by species GOA walleye pollock: age-2 GOA Pacific cod: age-0 GOA arrowtooth flounder: age-3 Lag time series to line up by age-0 Estimated in stock assessment models

(Cooper, 2006)

Data Marine fish recruitment 13 Eastern Bering Sea and Aleutian Islands (BSAI) stocks 15 Gulf of Alaska (GOA) stocks 31 California Current (CC) stocks Russian saffron cod

Data Salmon Ruggerone et al., 2010 Wild pink, chum, and sockeye salmon 12 regions in North America and Asia Catch + Escapement Lagged to year of ocean entry

Map of regional salmon stock groups (Ruggerone et al., 2010) Western AK Russia Mainland & Islands

Data Crabs Recruitment estimates from stock assessments Lagged to age-0 6 Eastern Bering Sea stocks 1 Gulf of Alaska stock Other Eastern Bering Sea zooplankton biomass Eastern Bering Sea jellyfish biomass 106 biological time series total

Stock-recruitment relationship Account for influences of spawning stock biomass on recruitment May be impacted by fishing Beverton Holt Ricker Constant Residuals from best model GOA arrowtooth flounder recruitment and spawning stock biomass time series and Beverton-Holt model fit

Multivariate analysis Reduce these 106 time series into a smaller number of uncorrelated time series Three methods Principal component analysis Non-metric multidimensional scaling Dynamic factor analysis Similar results for all- only presenting PCA results

PC 1: 12.5% of variance PC 2: 9.6% of variance

NW Pacific salmon GOA marine fish EBS flatfish

Correlation with physical variables PC 1 positively correlated with: Arctic Oscillation Index (r=0.40) Multivariate El Nino-Southern Oscillation Summer Index (r=0.42) Pacific Decadal Oscillation Summer Index (r=0.50) PC 2 positively correlated with Pacific Decadal Oscillation Summer Index (r=0.63)

Winter SST Summer SST Winter SLP Summer SLP PC 1 Correlation with SST and SLP

Winter SST Summer SST Winter SLP Summer SLP PC 2 Correlation with SST and SLP

Conclusions Common patterns are exhibited by marine species throughout the North Pacific Similar to those identified by Hare and Mantua (2000) Loadings on these patterns seem related to region and life history Large scale physical forces coordinate environment/ecosystem changes important to many stocks using different habitats across large distances We hypothesize this is a consequence of multiple mechanisms operating in different places at the same time A mixed-bag of sometimes similar and sometimes different mechanisms at play for different stocks within and between large marine ecosystems

Extra slides

Gulf of Alaska

California Current

Eastern Bering Sea and Aleutian Islands