1. A Satellite-tracked Drifter Perspective of the Nearshore Bering Sea: Science & Community Involvement aka: Bering Sea Drifters - Goin’ with the flow… Tom Weingartner 1, Terry Reeve 2, Seth Danielson 1, Warren Jones 3 1 Institute of Marine Science, U. Alaska Fairbanks, Fairbanks, AK 2 Marine Advisory Program, U. Alaska Fairbanks, Bethel, AK 3 Quinhagak Village Council, Quinhagak, AK An Arctic Yukon-Kuskokwim Sustainable Salmon Initiative Project

2. Talk Outline Motivation & Background 2002 & 2008 Deployments Results & Implications Community Partnerships Summary

3. Figure from AFSC web page: http://www.afsc.noaa.gov/ABL/OCC/ablocc_basis_aykjcse.htm 2005 BASIS Survey Juvenile Chum Salmon Distribution Idealized Circulation Cartoon Motivating Issues What is the fate of the (fresh) river discharge? What is the role of ocean circulation in determining the spatial distribution of young salmon?

4. CTD data courtesy Lisa Eisner and the BASIS program 1. Tides 2. Wind 3. Buoyancy 2004 Density distribution Red colors = greater density Blue colors = lesser density Y K Depth (m) Latitude Longitude Forces leading to surface circulation

5. 2002 NPRB Deployments Deployed by Larson King of Mekoryuk, Nunivak Island 15 drifters Exhibited both northward and westward motion Nunivak Island [Danielson, et. al., 2006]

6. 2008 AYKSSI Deployments Deployed by Quinhagak community residents & students 32 drifters deployed between June and September –8 deployments in clusters of 4 Final data transmission received January 7 th, 2009

7. Drifters appear to be trapped inside a frontal zone until late August, at which point they break through and progress westward.

8. 2008 Results Tidal Circulation –Flow steered by bathymetry –Stronger & rectilinear in shallower nearshore regions –Circular in deeper, flatter regions of the shelf Subtidal Circulation –Mean westward drift –~45% of the subtidal motion is accounted for by winds –Drifters move at a 30º angle to the right of the wind M 2 (12-hour) Tidal Current EllipsesMean Subtidal Circulation

9. Seasonal Drifter Patterns Only drifters deployed in June entered Etolin Strait Net westward drift at nearly all grid points in fall months June – AugustSeptember – January

10. Observations & Implications Surface outflow from Kuskokwim Bay shows two preferred pathways: –to the west in northern Kuskokwim Bay and –to the south in eastern Kuskokwim Bay Juvenile salmon timing of outmigration with respect to both river discharge and the wind field could be important to life history. –How long are young salmon trajectories strongly influenced by oceanic circulation? Dispersal of fresh water to the central shelf: –Flooding the central shelf with fresh waters can impact the central shelf nutrient budget. –Does this happen every year?

11. Nutrient & Salinity Field Implications BASIS CTD data analysis shows: 1. Salinities exhibit nearshore/offshore anti-correlation. 2. Previous winter’s cross-shore wind-driven transport is highly correlated with the end of summer fresh water anomaly. [Danielson, et. al., in prep.] Correlation Coefficient 2002-2007 Salinity Correlation Salinity NO 3 (μM) Nutrient & CTD Data courtesy Lisa Eisner and the BASIS program 2002-2006 Nitrate:Salinity Relation

12. Community Partnerships

13. June 21, 2008 Field Crew

14. Deployment

15. Classroom Demonstration

17. Summary Two seasonal (?) modes of inner shelf circulation: –Summer: Buoyancy-influenced (northwestward) –Fall: Wind-influenced (westward) Might influence dispersal and fate of juvenile salmon Fall winds force fresh, low-nitrate water onto the middle shelf – could affect spring nitrate levels and integrated bloom magnitude Wind-surface current relation allows retrospective study using winds (future effort) Community involvement is essential –Cost-effective –Project ownership –Educational

18. Upcoming 2009 Deployments 32 more drifters to be deployed in Kuskokwim Bay! You can track their daily progress at our web page: http://www.ims.uaf.edu/drifters Acknowledgements: Larson King - 2002 Deployments James Williams - 2008 Boat Captain Walter Bigjohn - 2008 Boat Captain Ron Kaiser- 2008 Boat Captain Cameron Debilt - Student Deployment Participant Jeffrey Pleasant - Student Deployment Participant Willis Small - Student Deployment Participant Jaime Nick - Student Deployment Participant Matt Debilt - Student Deployment Participant Melissa Merritt - Student Deployment Participant Lisa Eisner - CTD & Nutrient data Deborah Mercy - Photography Matthew Sisson – High School Student/Undergraduate Web Page Programmer Shawn Harper - Drifter on-shore recovery and re-deployment Drifter animation soundtrack: Barbara Lamb - Sally Goodin 2002 Deployment Funding: NPRB 2008 & 2009 Deployment Funding: AYKSSI