A1 Journal article (refereed)
Can regime shifts in reproduction be explained by changing climate and food availability? (2023)

Tirronen, M., Depestele, J., & Kuparinen, A. (2023). Can regime shifts in reproduction be explained by changing climate and food availability?. Frontiers in Marine Science, 10, Article 1167354. https://doi.org/10.3389/fmars.2023.1167354

JYU authors or editors

Tirronen, Maria
Kuparinen, Anna

Publication details

All authors or editors: Tirronen, Maria; Depestele, Jochen; Kuparinen, Anna

Journal or series: Frontiers in Marine Science

eISSN: 2296-7745

Publication year: 2023

Publication date: 11/10/2023

Volume: 10

Article number: 1167354

Publisher: Frontiers Media SA

Publication country: Switzerland

Publication language: English

DOI: https://doi.org/10.3389/fmars.2023.1167354

Publication open access: Openly available

Publication channel open access: Open Access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/90012

Abstract

Marine populations often show considerable variation in their productivity, including regime shifts. Of special interest are prolonged shifts to low recruitment and low abundance which occur in many fish populations despite reductions in fishing pressure. One of the possible causes for the lack of recovery has been suggested to be the Allee effect (depensation). Nonetheless, both regime shifts and the Allee effect are empirically emerging patterns but provide no explanation about the underlying mechanisms. Environmental forcing, on the other hand, is known to induce population fluctuations and has also been suggested as one of the primary challenges for recovery. In the present study, we build upon recently developed Bayesian change-point models to explore the contribution of food and climate as external drivers in recruitment regime shifts, while accounting for density-dependent mechanisms (compensation and depensation). Food availability is approximated by the copepod community. Temperature is included as a climatic driver. Three demersal fish populations in the Irish Sea are studied: Atlantic cod (Gadus morhua), whiting (Merlangius merlangus) and common sole (Solea solea). We demonstrate that, while spawning stock biomass undoubtedly impacts recruitment, abiotic and biotic drivers can have substantial additional impacts, which can explain regime shifts in recruitment dynamics or low recruitment at low population abundances. Our results stress the importance of environmental forcing to capture variability in fish recruitment.

Free keywords: allee effect; environmental forcing; non-linear recruitment dynamics; regime shifts; population recovery

Fields of science: