NPRB Gulf of Alaska Integrated Ecosystem Research Program Upper Trophic Level Component

1. Surviving the Gauntlet A comparative study of the pelagic, demersal, and spatial linkages that determine groundfish recruitment and diversity in the Gulf of Alaska ecosystem NPRB Gulf of Alaska Integrated Ecosystem Research Program Upper Trophic Level Component Jamal Moss, Kalei Shotwell, Shannon Atkinson, & Franz Mueter

2. UTL Introduction and Overview • Gulf of Alaska (GOA) • Highly complex and dynamic marine environment • Strong gradients in population stability and species composition over space and time • Mechanisms are poorly understood • Purpose • Improve our understanding of the variability in this ecosystem through regional comparison of recruitment variability in five predatory fish species and examine the effects of this variability on top level predators such as seabirds and Steller sea lions

3. UTL Core Hypotheses • Early life survival of marine fish • Influenced by climate driven variability in a biophysical gauntlet • Described by productivity, transport, and settlement • Linked to health and condition of fish traveling the gauntlet • Dietary preference and foraging strategy of top level predators (seabirds & Steller sea lions) • Influenced by fluctuations of available prey • Linked to differences in survival of fish among years and areas • Eastern GOA more ecologically resilient to climate change and human forcing than central GOA • Environmental and biological variability are less pronounced • Greater stability and higher species diversity

4. UTL Objectives • Quantify temporal variability of drivers influencing early life survival of key groundfish species by region • Retrospective analysis of available datasets • Determine abundance, distribution, and condition of key groundfish species during the pelagic stage • Field sampling via gridded stations by region • Laboratory work for health assessment in pelagic stage • Create habitat suitability maps to characterize nearshore demersal habitat by region • Analyze dietary preference and foraging behavior of top level predators and relate diet to available prey • Seabirds and Steller sea lions

5. Supporting Objectives • LTL/Physical Oceanography • Characterize biophysical environment for larval and juvenile fishes in eastern and central GOA • Dominant physical mechanisms for transport • Cross-shelf patterns in prey fields • Coordinate with modeling component to help "groundtruth" the bio-physical model • MTL/Forage Base • Characterize forage fish distribution and abundance in the eastern and central GOA relative to YOY of our focal species • During offshore/nearshore pelagic and nearshore settlement stages • Coordinate with modeling component to inform various models

6. Supporting Objectives • Modeling Component • Develop biophysical model to generate hindcasts & potentially forecasts of LTL variability for key prey groups • Quantify the effects of LTL variability on recruitment, competition, and predator-prey interactions among key groundfish species • Develop recruitment indices for at least two species with contrasting dispersal rates, we recommend sablefish & POP • Model connectivity between spawning areas and suitable nursery areas under different environmental conditions • Conduct Management Strategy Evaluations (MSE) through simulation of multi-species dynamics under different climate and fishing scenarios • Coordinate with LTL and MTL to groundtruth and inform models

7. Background & Justification • Recruitment • Focus on egg to Young-of-the-Year (YOY) critical period • Functional grouping of five top predatory groundfish • Pacific Cod, Pollock, Sablefish, POP, Arrowtooth Flounder • Majority of predator biomass in GOA & variety of life histories • Competition, predation, & environmental variability • Recruitment less related to fishing and adult spawning biomass • Regional comparison • Eastern GOA: stable, narrow shelf, high diversity, lower biomass • Central GOA: variable, wide shelf, low diversity, higher biomass

8. Proposed Activities and Objectives • Retrospective analysis • Offshore to nearshore pelagic stage • Nearshore settlement stage • Health assessment • Top predator stage

9. Retrospective Analysis • Goal • Provide baseline information on ecosystem processes at multiple trophic levels in the eastern and central GOA • Objectives • Quantify temporal variability at multiple trophic levels and identify cold & warm “regimes” • Characterize faunal break between eastern & central GOA - inshore to offshore and across trophic levels • Provide indices to modeling components • Approach • Compile relevant data sets (e.g. Table 1 in proposal) • Univariate & multivariate analysis of spatial & temporal patterns of variability

10. Potential Datasets

11. Offshore/Nearshore Pelagic Stage • Goal • Characterize offshore to nearshore pelagic environment for determining successful recruitment of key groundfish species • Objectives • Determine abundance and spatial distribution of five groundfish species and quantify regional differences • Describe surrounding environmental conditions to include oceanography, prey, competitor, and predator fields • Approach • Comprehensive pelagic sampling grid in two regions (Figure 1) • Seasonal at-sea sampling • Physical and biological oceanographic measurements (all seasons) • Surface trawling similar to BASIS and GLOBEC (summer/fall) • Avian and marine mammal observations (summer/fall)

12. East Amatuli Proposed Survey Station Grid Figure 1

13. Nearshore Settlement Stage • Goal • Describe preferred habitat and characterize nearshore for determining successful recruitment of key groundfish species • Objectives • Develop habitat suitability maps for five groundfish species and quantify regional differences • Determine role of nearshore habitat, prey, competitor and predator fields for successful settlement • Approach • Combine detailed bathymetry, substrate, and species habitat preferences to create habitat suitability maps by region • Overlay data on nearshore prey, competitor, and predator fields to predict ability of YOY to feed, compete, and avoid predation • Nearshore stations from existing and new surveys

16. Health Assessment • Goal • Measure health of key groundfish species throughout biophysical gauntlet to link to successful recruitment • Objectives • Estimate instantaneous growth, condition, and consumption rates throughout gauntlet • Develop bioenergetic models of potential fish growth for each species, region, and habitat • Approach • Calculate metabolic and consumption rates in laboratory from samples taken during at-sea surveys • Estimate growth potential by evaluating prey quality/consumption and instantaneous growth • Use condition estimates to develop simple bioenergetics models

17. TSMRI Laboratory

18. Top Predator Pelagic Stage • Goal • Determine predation pressure on YOY marine fish and prey accessibility during pelagic stage • Objectives • Estimate predator field during summer and fall offshore to nearshore pelagic surveys • Identify potential hotspots of foraging activity and relate to environmental observations • Approach • Conduct standard transect surveys for seabirds and marine mammals, and surface trawl or existing surveys for fish • Compare foraging activity to station oceanography and satellite measurements to identify hotspots

19. Seabird Diet • Goal • Determine relationship between factors influencing recruitment success of key groundfish species and changes in dietary preference and foraging strategy of seabirds • Objectives • Compare dietary preference and foraging strategy in seabirds for eastern and central GOA • Approach • Continue standard diet collections on St. Lazaria and East Amatuli islands • Equip rhinoceros auklets with platform terminal transmitter tags to evaluate feeding patterns during chick-rearing • Quantify time-budgets for nesting, foraging habits and effort

20. Seabird Observations • Onboard seabird observations • Spatial, temporal, and seasonal distribution • Diet collections at St. Lazaria and East Amatuli • Summers 2012-2013 • Rhinoceros auklet PTT tagging • Evaluate foraging patterns during chick rearing • Quantification of time-budgets while on land • Auklet chick enumeration & growth rate Rhinoceros auklet Fork-tailed storm-petrel Common Murre Leach’s storm-petrel Tufted Puffin

21. Steller sea lion (SSL) Diet • Goal • Determine relationship between factors influencing recruitment success of key groundfish species and changes in dietary preference and foraging strategy of SSL • Objectives • Compare dietary preference and foraging strategy in SSL for eastern and central GOA • Approach • Undertake scat collections and analysis from eastern and central SSL rookeries and haulouts • Estimate frequency of occurrence of prey species for various age and sex classes of SSL • Calculate diet diversity index by region and compare with abundance trends

22. Steller Sea Lion Observations • Enumeration (pups, males, females) • Scat collections from eastern and central regions (2012-2013) • Fish hard part analysis/diet composition • Corticosterone assay to test for age and sex effects on diet • Diet diversity index calculated for each region

23. Data Products • Retrospective Analysis • Datasets, spatial indices • Sampling Grid • Distribution and abundance of predatory fish species • Habitat • Detailed bathymetry and substrate maps • Suitability maps and indices by species, region • Health Assessment • Growth estimates, metabolic and consumption rates • Top Predators • Density estimates from at-sea transects • Diet data for seabirds and Steller sea lions

24. Products Timeline

25. Fisheries Oceanographic Surveys • CTD cast to 10m from bottom or 200m • Zooplankton net tows (2) • 30-minute surface trawl • Underway seabird and marine mammal observations http://globec.oce.orst.edu

26. Fish Collections

29. Sampling Logistics 2011 2012 2013 Summer (July/Aug) Autumn (Sept/Oct) Space for 3 LTL and MTL scientists on charter, 6 on Oscar Dyson

30. Data Needs • LTL Component: • Spring survey to characterize biophysical environment and sample eggs/larvae • Estimates of biophysical environment during summer and fall surveys at each grid station • MTL Component: • Estimates of forage base during summer and fall surveys at each grid station and in the nearshore settlement areas • Modeling: • Biophysical model • Transport model for two species with contrasting dispersal rates • Identify POP samples and use genetic dispersal to inform transport model • Model quantifying effects of LTL variability on recruitment, competition, and predator-prey interactions among key groundfish species • MSE through simulations of different fishing and climate scenarios

31. Questions???

32. Required Products List