Characterizing the behavior and survival of age 1 hatchery stocked smolts in the Narraguagus River, Maine U.S.A.

NOAA's National Marine Fisheries Service (NOAA) has been evaluating emigrating Atlantic salmon (ATS) smolt dynamics and survival via acoustic telemetry within the Narraguagus River since 1997. Optimizing the number of smolts that enter the ocean from coastal rivers and into the Gulf of Maine is a management priority. Until recently, the Narraguagus River has been solely supported by natural reproduction and fry stocking within the watershed.

In 2008, a five year smolt stocking effort was implemented with intentions of boosting adult returns. Approximately 40,000 smolts were stocked annually over this five year period with limited success. 154 2SW adult returns were documented, which is 5.6 2SW adults per 10,000 smolts stocked. These results are much lower than the natural component (63.2/10,000) of the Narraguagus and returns from age 1 hatchery smolt stocking on other nearby systems during the same timeframe.

Through this effort we will investigate and describe the behavior and success of conservation hatchery smolt with differing release times migrating through the river, estuary, and nearshore environment to determine if there are differences between groups. In addition to migration performance, we will identify bottlenecks (predation, environment, habitat, etc) which will inform managers of areas of focus during restoration efforts within the watershed to optimize the number of post smolts entering the Gulf of Maine.