Impacts of the match-mismatch hypothesis across three trophic levels-a case study in the North Sea

Sustainable fishery practices require accurate predictions of fish recruitment-the abundance of a new year class entering a fishery. A key driver of recruitment is the impact predator-prey dynamics experienced during early life stages has on their survival at later stages, as in the Match-Mismatch Hypothesis (MMH). MMH states that predator survival depends on the match (or mismatch) between the timing of predator feeding and that of prey availability. This study aims to understand how predator-prey spatio-temporal overlap explains the variation in a pelagic fish population. We explore the predator-prey overlap between each pair of three trophic levels in the North Sea (NS) from 1982-2017: herring (Clupea harengus) larvae, zooplankton (Temora longicornis, Oithona sp.,Pseudocalanus spp., and Acartia spp.), and a phytoplankton index. We found that MMH explained 23% of recruitment (1-year-old) of NS autumn-spawning (NSAS) herring, performed similarly (21-26%) when using different trophic levels, and that there was a spatial pattern in both the overlap and the negative relationship between the overlap and recruitment, similar to the variation of habitat use of NS herring. Our results characterize how the MMH, including spatial variability, plays in controlling herring recruitment, while also considering unexplained variation for future study.

Automated summary

Sustainable fishery practices require accurate predictions of fish recruitment, and the Match-Mismatch Hypothesis (MMH) plays a role in explaining the variation in a pelagic fish population. This study explores the predator-prey spatio-temporal overlap and its relationship with herring recruitment in the North Sea. The results show that MMH explains a significant portion of herring recruitment and there is a spatial pattern in the overlap and its negative relationship with recruitment.