A fine-scale multi-step approach to understand fish recruitment variability

Area of Science:

• Marine Ecology
• Fisheries Science
• Population Dynamics

Background:

• Fish population productivity is largely regulated by recruitment, a complex, multi-step process.
• Predicting recruitment is difficult due to numerous fine-scale drivers influencing the pathway from adult populations to new individuals.

Observation:

• Analyzed Northwest Atlantic mackerel recruitment from 1982 to 2017.
• Investigated the interplay of demographic and environmental drivers on recruitment success.
• Examined the breakdown of broad-scale recruitment-environment relationships over time.

Findings:

• Larval survival, dependent on spatio-temporal prey match, is the key driver of mackerel recruitment.
• Maternal effects and parent-offspring feeding regime mismatches significantly mediate recruitment.
• Despite high prey availability, recruitment declined as prey mismatches curtailed larval survival.

Implications:

• Highlights the critical role of fine-scale processes in fish recruitment.
• Explains the instability of broad-scale recruitment-environment relationships.
• Suggests improved recruitment predictions and fisheries management strategies by considering these fine-scale dynamics.