Fish thermal habitat current use and simulation of thermal habitat availability in lakes of the Argentine Patagonian Andes under climate change scenarios RCP 4.5 and RCP 8.5

RECHENCQ, MAGALÍ M.; MACCHI, PATRICIO J.; FERNÁNDEZ, MARÍA V.; VIGLIANO, PABLO H.; LIPPOLT, GUSTAVO E.

THE SCIENCE OF TOTAL ENVIRONMENT

Elservier

Año: 2018 vol. 636 p. 688 - 698

0048-9697

Habitat use in relation to the thermal habitat availability and food source as a forcing factor on habitat selection and use of Percichthys trucha (Creole perch), Oncorhynchus mykiss (rainbow trout), Salmo trutta (brown trout) and Salvelinus fontinalis (brook trout) were determined as well as future potential thermal habitat availability for these species under climate change scenarios Representative Concentration Pathways 4.5 and 8.5. This study was conducted in three interconnected lakes of Northern Patagonia (Moreno Lake system). Data on fishabundance was obtained through gill netting and hydroacoustics, and thermal profiles and fish thermal habitat suitability index curves were used to identify current species-specific thermal habitat use. Surface air temperatures fromthe (NEX GDDP) database for RCP scenarios 4.5 and 8.5 were used to model monthly average temperatures of the water column up to the year 2099 for all three lakes, and to determine potential future habitat availability. In addition, data on fish dietwere used to determinewhether food could act as a forcing factor in current habitat selection. The four species examined do not use all the thermally suitable habitats currently availableto themin the three lakes, and higher fish densities are not necessarily constrained to their ?fundamental thermal niches? sensu Magnuson et al. (1979), as extensive use is made of less suitable habitats. This is apparently brought about by food availability acting as a major forcing factor in habitat selection and use. Uncertainties related to the multidimensionality inherent to habitat selection and climate change imply that fish resource