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

Sci Rep. 2020 Sep 30;10(1):16064. doi: 10.1038/s41598-020-73025-z.

Abstract

Recruitment is one of the dominant processes regulating fish population productivity. It is, however, notoriously difficult to predict, as it is the result of a complex multi-step process. Various fine-scale drivers might act on the pathway from adult population characteristics to spawning behaviour and egg production, and then to recruitment. Here, we provide a holistic analysis of the Northwest Atlantic mackerel recruitment process from 1982 to 2017 and exemplify why broad-scale recruitment-environment relationships could become unstable over time. Various demographic and environmental drivers had a synergetic effect on recruitment, but larval survival through a spatio-temporal match with prey was shown to be the key process. Recruitment was also mediated by maternal effects and a parent-offspring fitness trade-off due to the different feeding regimes of adults and larvae. A mismatch curtails the effects of high larval prey densities, so that despite the abundance of food in recent years, recruitment was relatively low and the pre-existing relationship with overall prey abundance broke down. Our results reaffirm major recruitment hypotheses and demonstrate the importance of fine-scale processes along the recruitment pathway, helping to improve recruitment predictions and potentially fisheries management.

Publication types

  • Historical Article
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Atlantic Ocean
  • Canada
  • Female
  • Fisheries* / history
  • Fisheries* / organization & administration
  • Fisheries* / statistics & numerical data
  • Fishes* / growth & development
  • Fishes* / physiology
  • Food Chain
  • History, 20th Century
  • History, 21st Century
  • Larva / growth & development
  • Male
  • Models, Biological
  • Perciformes / growth & development
  • Perciformes / physiology
  • Population Dynamics / history
  • Reproduction / physiology