Background

SALSEA North America and SALSEA-MERGE were developed around common themes to further the understanding of factors affecting marine survival of Atlantic salmon stocks on both sides of the North Atlantic. Several research activities described in SALSEA North America are expected to continue beyond the proposed two years of marine surveys. Many activities in the index rivers program have taken place over the past several decades and are anticipated to continue. Analysis of historical and ongoing data will continue as new techniques and hypotheses are developed for addressing the questions of population dynamics and ecology of Atlantic salmon.

A marine survey took place in August 2008 using the Fisheries and Oceans Canada research vessel, CCGS Wilfred Templeman. A further marine surveyby the CCGS Alfred Needler took place in September 2009.

Objectives

Questions to be addressed using data from the marine research survey:

• Where are the early marine phase nursery areas of Atlantic salmon?
• Are stocks from the greater than 600 rivers in eastern Canada mixed at sea?
• What are the other components of the pelagic community occupied by Atlantic salmon?
• What prey are they consuming relative to what is available?
• Are they being consumed by other fish predators within the pelagic zone?
• What has been their marine growth profile and how does it differ from the profile of subsequent survivors the following year?
• What is their disease profile compared to profiles of outgoing smolts?
• What is the parasite community and does it differ in smolts going to sea from adults returning?
• Are maturing (grilse) and non-maturing (multi-sea-winter) salmon mixed at sea or have they segregated and use different parts of the ocean?
• Are there aquaculture escapees in the same areas as the wild fish?