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Cormorant predation effects on fish populations: A global meta-analysis

Ovegård, Maria and Jepsen, Niels and Bergenius, Mikaela and Petersson, Erik (2021). Cormorant predation effects on fish populations: A global meta-analysis. Fish and Fisheries. 22 , 605-622
[Research article]

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This paper provides the results from the first meta-analysis to examine the impact of cormorant (Phalacrocoracidae) predation on fish. It is based on a systematic search of literature, covering studies using significance-based hypotheses tests on the relation between fish parameters and cormorant abundance. The results show that extensive research on cormorant diet exists, but few studies use statistical hypotheses testing to examine the effect on fish populations. In total, 603 publications were identified from titles and abstracts, to include the interaction between cormorants and fish. From these, 27 articles tested fish population parameters against cormorant predation, whereof 22 could be included in analyses. The effect size was defined negative in cases when cormorant numbers or presence reduced fish numbers or biomasses, or when individual fish sizes decreased, and vice versa for a positive effect. In a hierarchical dependence model, the combined effect of cormorant predation on fish was negative, but the overall effect was not significant at the 95% confidence level (-0.169, 95% C.L. -0.505 to 0.167, p = .256, df = 5.26). A covariate analysis revealed a difference in predatory effects between fish prey taxa (p = .006, df = 5.73), but no difference in effect sizes between study type, foraging habitat, or response variable measured. The meta-analysis reveals a complex interaction between cormorants and fish, but adds to the consensus on the importance of considering cormorant predatory effects in research, conservation actions, ecosystem-based management, and environmental monitoring.

Authors/Creators:Ovegård, Maria and Jepsen, Niels and Bergenius, Mikaela and Petersson, Erik
Title:Cormorant predation effects on fish populations: A global meta-analysis
Series Name/Journal:Fish and Fisheries
Year of publishing :2021
Page range:605-622
Number of Pages:18
Publication Type:Research article
Article category:Scientific peer reviewed
Version:Published version
Copyright:Creative Commons: Attribution-Noncommercial-No Derivative Works 4.0
Full Text Status:Public
Subjects:(A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 401 Agricultural, Forestry and Fisheries > Fish and Aquacultural Science
Keywords:cormorant, effect, management, meta‐analysis, Phalacrocorax, predation, wildlife‐conflict
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Additional ID:
Type of IDID
Web of Science (WoS)000614599200001
ID Code:25500
Faculty:NJ - Fakulteten för naturresurser och jordbruksvetenskap
Department:(NL, NJ) > Department of Aquatic Resources
Deposited By: SLUpub Connector
Deposited On:24 Sep 2021 12:25
Metadata Last Modified:24 Sep 2021 12:31

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