Variability in the functional role of Arctic charr Salvelinus alpinus as it relates to lake ecosystem characteristics

• Published in: Environmental biology of fishes Vol. 96; no. 12; pp. 1361 - 1376
• Main Authors: Woods, Pamela J., Skúlason, Skúli, Snorrason, Sigurður S., Kristjánsson, Bjarni K., Ingimarsson, Finnur, Malmquist, Hilmar J.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-12-2013; Springer; Springer Nature B.V
• Subjects: Agnatha. Pisces; Animal and plant ecology; Animal Systematics/Taxonomy/Biogeography; Animal, plant and microbial ecology; Animals; Aquatic ecosystems; Autoecology; Biological and medical sciences; Biomedical and Life Sciences; Bosmina; Cladocera; Environment; Feeding behavior; Food chains; Food webs; Fresh water ecosystems; Freshwater; Freshwater & Marine Ecology; Freshwater ecosystems; Fundamental and applied biological sciences. Psychology; Gasterosteus aculeatus; General aspects; Habitats; Lakes; Lepidurus arcticus; Life Sciences; Nature Conservation; Nutrient concentrations; Pisidium; Plankton; Predation; Prey; Radix peregra; Resource consumption; Salmo trutta; Salvelinus alpinus; Synecology; Trout; Vertebrata; Zoology; ANE, Atlantic, Iceland; Piscivory; Zooplanktivory; Prey habitat; Diet; Consumer; Lake ecosystem; Planktonophagous; Feeding; Freshwater environment; Prey; Piscivorous; Vertebrata; Ecosystem; Pisces; Lakes; Habitat; Salvelinus alpinus; Zooplankton
• ISSN: 0378-1909; 1573-5133
• DOI: 10.1007/s10641-013-0114-x

This study investigated how dietary habits vary with lake characteristics in a fish species that exhibits extensive morphological and ecological variability, the Arctic charr
Salvelinus alpinus
. Iceland is a hotspot of geological activity, so its freshwater ecosystems vary greatly in physical and chemical attributes. Associations of dietary items within guts of charr were used to form prey categories that reflect habitat-specific feeding behavior. Six prey categories were defined and dominated by snails (
Radix peregra
), fish (
Gasterosteus aculeatus
), tadpole shrimp (
Lepidurus arcticus
), chironomid pupae, pea clam (
Pisidium
spp.), and the cladoceran
Bosmina
sp.. These reflected different combinations of feeding in littoral stone, offshore benthic, and limnetic habitats. Certain habitat-specific feeding strategies consistently occurred alongside each other within lakes. For example, zooplanktivory occurred in the same lakes as consumption from offshore habitats; piscivory occurred in the same lakes as consumption from littoral benthic habitats. Redundancy analyses (RDA) were used to investigate how lake environment was related to consumption of different prey categories. The RDA indicated that piscivory exhibited by Arctic charr was reduced where brown trout were abundant and lakes were shallow, greater zooplanktivory occurred at lower latitudes and under decreased nutrient but higher silicon dioxide concentrations, and benthic resource consumption was associated with shallower lakes and higher altitudes. This study showed that trends previously observed across fish species were supported at the intraspecific level, indicating that a single species with flexible dietary habits can fill functional roles expected of multiple species in more diverse food webs.