Impacts of a changing ecosystem on Atlantic salmon marine productivity

Katherine E. Mills, Gulf of Maine Research Institute

ABSTRACT

Atlantic salmon populations have declined throughout North America and Europe in recent

decades. These declines have exhibited similar patterns over broad geographic areas, and

previous studies have shown correlations between salmon declines and changing marine

ecosystem conditions. These analyses have specifically identified warming ocean conditions and

changes in the prey base as closely linked with Atlantic salmon population trends. The

observed ecosystem changes have likely increased the energy requirements of Atlantic salmon

and reduced the energy available to them through their prey. However, the mechanisms behind

these relationships remain undiagnosed. Through this project, we will investigate the

hypothesis that ecosystem changes have influenced the energy needed by and available to

Atlantic salmon and thereby have affected salmon growth, survival, and productivity during

their marine phase.

Results will provide a better understanding of how marine ecosystem conditions affect Atlantic

salmon populations, which is valuable information for evaluating their recovery prospects and

constraints.