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Interacting forces of predation and fishing affect speciesí maturation size


Forestier, R and Blanchard, JL and Nash, KL and Fulton, EA and Johnson, C and Audzijonyte, A, Interacting forces of predation and fishing affect species' maturation size, Ecology and Evolution, 10, (24) pp. 14033-14051. ISSN 2045-7758 (2020) [Refereed Article]


Copyright Statement

© 2020 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

DOI: doi:10.1002/ece3.6995



1. Fishing is a strong selective force and is supposed to select for earlier maturation at smaller body size. However, the extent to which fishing-induced evolution is shaping ecosystems remains debated. This is in part because it is challenging to disentangle fishing from other selective forces (e.g. size-structured predation and cannibalism) in complex ecosystems undergoing rapid change.
2. Changes in maturation size from fishing and predation have previously been explored with multi-species physiologically structured models but assumed separation of ecological and evolutionary timescales. To assess the eco-evolutionary impact of fishing and predation at the same timescale, we developed a stochastic physiologically size-structured food web model, where new phenotypes are introduced randomly through time enabling dynamic simulation of speciesí relative maturation sizes under different types of selection pressures.
3. Using the model, we carried out a fully factorial in silico experiment to assess how maturation size would change in the absence and presence of both fishing and predation (including cannibalism). We carried out ten replicate stochastic simulations exposed to all combinations of fishing and predation in a model community of nine interacting fish species ranging in their maximum sizes from 10g to 100kg. We visualised and statistically analysed the results using linear models.
4. The effects of fishing on maturation size depended on whether or not predation was enabled and differed substantially across species. Fishing consistently reduced the maturation sizes of two largest species whether or not predation was enabled and this decrease was seen even at low fishing intensities (F = 0.2yr−1 ). In contrast, the maturation sizes of the three smallest species evolved to become smaller through time but this happened regardless 2 of the levels of predation or fishing. For the four medium-size species, the effect of fishing was highly variable with more species showing significant and larger fishing effects in the presence of predation.
5. Ultimately our results suggest that the interactive effects of predation and fishing can have marked effects on speciesí maturation sizes, but that, at least for the largest species, predation does not counterbalance the evolutionary effect of fishing. Our model also produced relative maturation sizes that are broadly consistent with empirical estimates for many fish species.

Item Details

Item Type:Refereed Article
Keywords:fisheries induced evolution, ecosystem modelling, multi-species models, size based ecology, body size, coexistence, evolution, fisheries, food webs, multi-species size spectrum model
Research Division:Environmental Sciences
Research Group:Ecological applications
Research Field:Ecosystem function
Objective Division:Animal Production and Animal Primary Products
Objective Group:Fisheries - wild caught
Objective Field:Fisheries - wild caught not elsewhere classified
UTAS Author:Forestier, R (Dr Romain Forestier)
UTAS Author:Blanchard, JL (Professor Julia Blanchard)
UTAS Author:Nash, KL (Dr Kirsty Nash)
UTAS Author:Fulton, EA (Dr Elizabeth Fulton)
UTAS Author:Johnson, C (Professor Craig Johnson)
UTAS Author:Audzijonyte, A (Dr Asta Audzijonyte)
ID Code:141860
Year Published:2020
Web of Science® Times Cited:3
Deposited By:Ecology and Biodiversity
Deposited On:2020-11-26
Last Modified:2021-02-22
Downloads:21 View Download Statistics

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