Open AccessDisentangling conditional effects of multiple regime shifts on Atlantic cod productivity
Author(s) -
Tommi Perälä,
Esben Moland Olsen,
Jeffrey A. Hutchings
Publication year - 2020
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0237414
Subject(s) - regime shift , productivity , abundance (ecology) , north atlantic oscillation , zooplankton , fishing , environmental science , climate change , marine ecosystem , oceanography , sea surface temperature , ecosystem , fishery , ecology , geography , biology , economics , geology , macroeconomics
Regime shifts are increasingly prevalent in the ecological literature. However, definitions vary and detection methods are still developing. Here, we employ a novel statistical algorithm based on the Bayesian online change-point detection framework to simultaneously identify shifts in the mean and (or) variance of time series data. We detected multiple regime shifts in long-term (59–154 years) patterns of coastal Norwegian Atlantic cod (>70% decline) and putative drivers of cod productivity: North Atlantic Oscillation (NAO); sea-surface temperature; zooplankton abundance; fishing mortality ( F ). The consequences of an environmental or climate-related regime shift on cod productivity are accentuated when regime shifts coincide, fishing mortality is high, and populations are small. The analyses suggest that increasing F increasingly sensitized cod in the mid 1970s and late 1990s to regime shifts in NAO, zooplankton abundance, and water temperature. Our work underscores the necessity of accounting for human-induced mortality in regime shift analyses of marine ecosystems.