Linkage Between Coastal Conditions and Migratory Patterns and Behavior of Atlantic Salmon Smolts Along the Halifax Line

Mathieu Dever, Dalhousie University, Oceanography, Halifax, NS, Canada, John Kocik, NOAA fisheries, Northeast Fisheries Science Center, Orono, ME, United States, Joseph Zydlewski, U.S. Geological Survey, Maine Cooperative Fish and Wildlife Research Unit, Orono, ME, United States, David Hebert, Department of fisheries and oceans, Bedford Institute of Oceanography, Dartmouth, NS, Canada and Daniel Stich, University of Maine, Dept. of Wildlife, Fisheries and Conservation Biology, Orono, ME, United States
Understanding nearshore migration of Atlantic Salmon is a key to further improve management and conservation of this species. While monitoring migration remains a challenge, the rapid development of fish tracking techniques and fixed listening arrays leads to unprecedented opportunities to map migration routes and measure their spatial and temporal variability. Interpretation and analysis of animal detection patterns relies critically on simultaneous collection of environmental data. This study focuses on the migratory patterns and behavior of Atlantic Salmon smolts tagged in the Penobscot River (ME, USA) over the 2008-2014 period and detected along the Halifax Line; A fixed array of 256 acoustic receiver stations crossing the Scotian Shelf and deployed as part of the Ocean Tracking Network research program. It links inter-annual temporal and spatial variability to co-located oceanographic data collected from many different platforms (ADCPs, gliders, etc). The migratory behaviour (heading, patterns in repeated detection, time spent at the line, etc.) is described, and cross-shelf movement are compared to oceanographic variables. It demonstrates that the smolts are generally heading into a direction contained between 51° and 118° from True North. It also shows that tidal current do not explain the cross-shore movement of the smolts.