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 thes 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.