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Nancy Shackell 1 *, Alida Bundy 1 , Janet Nye 2 , Jason Link 2

Ecosystem Drivers in the Northwest Atlantic : A Comparison of Canadian and US Indicators from Several, Contiguous Regional Ecosystems. Nancy Shackell 1 *, Alida Bundy 1 , Janet Nye 2 , Jason Link 2

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Nancy Shackell 1 *, Alida Bundy 1 , Janet Nye 2 , Jason Link 2

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  1. Ecosystem Drivers in the Northwest Atlantic:A Comparison of Canadian and US Indicators from Several, Contiguous Regional Ecosystems Nancy Shackell1*, Alida Bundy1, Janet Nye2, Jason Link2 1Fisheries and Oceans, Canada, Bedford Institute of Oceanography, PO Box 1006, Dartmouth, NS B2Y 4A2, Canada; National Marine Fisheries Service, Northeast Fisheries Science Center, Woods Hole Laboratory, 166 Water Street, Woods Hole, MA 02543, USA.;3 NOAA NMFS Northeast Fisheries Science Center, Chief, Oceanography Branch 28 Tarzwell Drive,Narragansett, RI 02882 USA with various data provided by Michael Fogarty2, Ken Frank1, Jon Hare3, Erica Head1,Bill Overholtz2

  2. Q:Are there common ecological trends among 7 regions?

  3. Climate Fishing DRIVERS/PRESSURE MacroInverts RESPONSE

  4. How are DRIVERs correlated to trends ? Climate 5 Temp Indices 1 Stratification 3 Temperature CV Fishing Effects 1-Resource Potential Climate 6 fxnl grps 6 fxnl grps of 45 fish spp. 5 indices of Average Fish Size 1 Dominance 3 fxnl grps of Inverts 1 index Fishing Size MacroInverts RESPONSE Extract trend from multiple response time series…for each region (~ 22 vars/region)

  5. Multivariate Approach • Principal component analysis especially for time series. • MAFA (min/max autocorrelation factor analysis; Solow, A.R. 1994 Biometrics50, 556-565) • A method to extract trends from multiple time series

  6. Major Trend of Response Variables: NESW Monotonic Trend in thru 80’s to 1990 But ….which response variables contribute most to trend?

  7. Region: Gulf of Maine

  8. What are common signals among regions? (Focus on continuous time series in all regions)

  9. Do Common Drivers affect Trends?

  10. DRIVERS Correlation with Main Temporal Trend

  11. Summary of Common Trends In General-common signals in ESS, WSS, BoF, GoMa, ~GB RESPONSE • Planktivore /MacroInvertebrate INCREASE thru 80’s • Main Predator BM declined/steady/or increased late in time series (mixed bag) • Main Predator Size decline thru 80’s DRIVERS/PRESSURES: • AMO (now in warm phase) and Fishing Potential associated with Trends- • magnitude of association varies with region

  12. So now what?

  13. Next Steps. • Formally Explore Relative Contribution of Climate and Fishing to ecosystem trends. (+Labrador water) • Ecosystem Response is Contextual: Impact of climate change/fishing is exacerbated at higher latitudes • NORTH (ESS): Response to the two main drivers is stronger =Trophic Cascade • SOUTH (MAB) – no drivers very strong - Other drivers may be more important • Mid RANGE (WSS, GoM, BoF,~GB) : Climate forcing prevails– fishing appears secondary EXCEPT THAT… ….Reduction in Main Predator Size Predatory impact of main predators declined due to reductions in body size that facilitated an increase in prey

  14. Predator Size Planktivore Biomass Do larger predators regulate their prey more efficiently?

  15. the end

  16. PRINCIPAL COMPONENTS OVER TIME Rerun with InvGrs

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