Applications of the Pacific Ocean Shelf Tracking System (POST): A permanent continental-scale acoustic tracking array for fisheries research & ocean observation

The Pacific Ocean Shelf Tracking (POST) array was initially conceived and planned as a single continental scale acoustic tracking system for direct measurement of the marine movements and survival of animals in the ocean. With the success of the demonstration phase, POST is now transitioning into a single integrated global system of compatible arrays distributed throughout the continental shelves of all continents. 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 >1,200 kms of the west coast of North America. Detection rates of individual 12-16 cm long salmon smolts was >90% for a single acoustic listening line. 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. 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 other ocean sensors. Such a system would yield revolutionary advances in our ability to study the oceans. Our current efforts on the Pacific coast involve developing a permanent year-round array whose operation is less labour-intensive, more reliable, and provides this wider range of ocean observations at lower per unit cost, which will allow the deployment of a much more extensive array.