Evol Ecol Res 19: 149-169 (2018)     Full PDF if your library subscribes.

Eco-evolutionary feedbacks in the functional role of a polymorphic colonizer: Arctic charr in subarctic lakes of Alaska and Iceland

Pamela J. Woods^1,2,3,4, Skúli Skúlason¹, Sigurður S. Snorrason² and Thomas P. Quinn³

¹Hólar University College, Sauðárkrókur, Iceland,  ²University of Iceland, Reykjavík, Iceland, ³School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington, USA and  ⁴Marine and Freshwater Research Institute, Reykjavik, Iceland

Correspondence: P.J. Woods, Marine and Freshwater Research Institute, 101 Reykjavík, Iceland.

ABSTRACT

Background: The Arctic charr, Salvelinus alpinus, is likely to be the first fish to colonize northernmost freshwater systems. It often exhibits sympatric morphotypes.

Question: How do ecosystem characteristics and the life history of Arctic charr interact to generate food webs in subarctic lakes?

Organisms: We focus on allometric dietary patterns of Arctic charr. We compare them with selected, co-occurring fish species, including threespine stickleback (Gasterosteus aculeatus) among others, and both benthic and limnetic invertebrates.

Field sites: Subarctic lakes in two regions that differ greatly in colonization history (ten in Iceland and four in Alaska).

Methods: We used natural variation in the stable isotope ratios δ¹³C and δ¹⁵N to estimate trends in trophic position and relative use of benthic and limnetic carbon sources with body size among lakes and among species × morph × body size brackets within lakes.

Results: (1) In subarctic lakes with low levels of fish diversity, food chains lengthened via insertion of intermediate prey. (2) Ecosystem attributes, including the presence of competitors and competitor resource use, were associated with allometric shifts in Arctic charr resource use. (3) Species attributes, including the presence and nature of polymorphism exhibited by the Arctic charr, likewise shifted allometric trends in resource use. (4) Both the expression of resource polymorphism and interspecific interactions (i.e. predation, competition, or both) affected food web structure.

Keywords: Arctic charr, eco-evolutionary feedback, food web, resource polymorphism, subarctic lake.

DOWNLOAD A FREE, FULL PDF COPY
IF you are connected using the IP of a subscribing institution (library, laboratory, etc.)
or through its VPN.

 

        © 2018 Pamela J. Woods. All EER articles are copyrighted by their authors. All authors endorse, permit and license Evolutionary Ecology Ltd. to grant its subscribing institutions/libraries the copying privileges specified below without additional consideration or payment to them or to Evolutionary Ecology, Ltd. These endorsements, in writing, are on file in the office of Evolutionary Ecology, Ltd. Consult authors for permission to use any portion of their work in derivative works, compilations or to distribute their work in any commercial manner.

       Subscribing institutions/libraries may grant individuals the privilege of making a single copy of an EER article for non-commercial educational or non-commercial research purposes. Subscribing institutions/libraries may also use articles for non-commercial educational purposes by making any number of copies for course packs or course reserve collections. Subscribing institutions/libraries may also loan single copies of articles to non-commercial libraries for educational purposes.

       All copies of abstracts and articles must preserve their copyright notice without modification.