OTN recently released 15 grey seal “Bioprobes” on Sable Island, Nova Scotia, Canada, in the middle of its Atlantic technology proving grounds (see map below).
The photo to the right shows the first seal carrying a satellite tag on its head, to record its location and the oceanographic conditions where it dives, as well as an acoustic transmitter/receiver at the other end. The transmitters will be recorded by receivers as the seals pass over the completed portions of the Halifax and Cabot Strait Lines, and the receivers will detect approaches to other tagged animals in the region closer than about 0.5 km. If the seals capture tagged prey, there should be many hours of records as the prey are digested.
Recent projects have tagged Atlantic salmon, Atlantic bluefin tuna, and cod, all expected to cross OTN Lines and travel where interactions with seals are possible. A 90% recovery rate of tags over 10 years promises good prospects for reintegration of time-stamped acoustic detections with known locations and conditions. This is the first test of the Atlantic Arena concept, which promises to provide powerful new tools for understanding ecosystem interactions in the open ocean, useful for ecosystem-based management.
The Atlantic Arena has ongoing acoustic tagging programs for many of the species listed on the map above (right) and a 10-year history of satellite tracking of grey seals from the Sable Island breeding population, showing that they spread out from Cape Cod to Quebec when feeding.
Story by Ron O’Dor, OTN Global Scientific Director