A continental-scale ocean observation system to gather biological and oceanographic data for marine resource management

The Pacific Ocean Shelf Tracking project (POST), one of the Census of Marine Life field projects, is a seabed acoustic array for tracking marine animals. Field trials in 2004 and 2005 involved the deployment of 6 major listening lines, each about 20 km long, laid out to track the migration and survival of salmon smolts along the west coast of North America. Detection rates of salmon smolts implanted with individually identifiable acoustic tags crossing these lines was >90%. Precise measurements of migration timing, travel speeds and survival were obtained for the freshwater and early marine phases of various salmon stocks. The results demonstrate that it is possible to measure survival and movement directly in the ocean, and that the technology can be applied to a wide range of fish species. Current efforts involve developing a permanent array whose operation is less labour-intensive, more reliable, and provides a wider range of ocean observations. Although a key component of the array is the ability to provide a nearly complete census of the movements and survival of marine fish such as salmon, the array concept has much broader utility and can host a wide range of ocean sensors. Such a system could yield revolutionary advances in our ability to study the oceans.