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Research article - Peer-reviewed, 2021

Predator biomass and vegetation influence the coastal distribution of threespine stickleback morphotypes

Yanos, Casey L.; Haanstra, Eeke P.; Carey, Fiona Colgan; Passmore, Sorsha A.; Eklof, Johan S.; Bergstrom, Ulf; Hansen, Joakim P.; Fontaine, Michael C.; Maan, Martine E.; Eriksson, Britas Klemens


Intraspecific niche differentiation can contribute to population persistence in changing environments. Following declines in large predatory fish, eutrophication, and climate change, there has been a major increase in the abundance of threespine stickleback (Gasterosteus aculeatus) in the Baltic Sea. Two morphotype groups with different levels of body armor-completely plated and incompletely plated-are common in coastal Baltic Sea habitats. The morphotypes are similar in shape, size, and other morphological characteristics and live as one apparently intermixed population. Variation in resource use between the groups could indicate a degree of niche segregation that could aid population persistence in the face of further environmental change. To assess whether morphotypes exhibit niche segregation associated with resource and/or habitat exploitation and predator avoidance, we conducted a field survey of stickleback morphotypes, and biotic and abiotic ecosystem structure, in two habitat types within shallow coastal bays in the Baltic Sea: deeper central waters and shallow near-shore waters. In the deeper waters, the proportion of completely plated stickleback was greater in habitats with greater biomass of two piscivorous fish: perch (Perca fluviatilis) and pike (Esox lucius). In the shallow waters, the proportion of completely plated stickleback was greater in habitats with greater coverage of habitat-forming vegetation. Our results suggest niche segregation between morphotypes, which may contribute to the continued success of stickleback in coastal Baltic Sea habitats.


ecosystem perturbation; ecotypic divergence; habitat specialization; intraspecific variation; stickleback

Published in

Ecology and Evolution
2021, volume: 11, number: 18, pages: 12485-12496
Publisher: WILEY

Authors' information

Yanos, Casey L.
University of Groningen
Haanstra, Eeke P.
University of Groningen
Carey, Fiona Colgan
University of Groningen
Passmore, Sorsha A.
University of Groningen
Eklof, Johan S.
Stockholm University
Swedish University of Agricultural Sciences, Department of Aquatic Resources
Hansen, Joakim P.
Stockholm University
Fontaine, Michael C.
University of Groningen
Maan, Martine E.
University of Groningen
Eriksson, Britas Klemens
University of Groningen

Associated SLU-program

Coastal and sea areas

Sustainable Development Goals

SDG14 Life below water

UKÄ Subject classification


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