Modeling the effects of climate change on the distribution of Salmo trutta in Urmia lake Basin Rivers

Abstract

Introduction: Nowadays, based on the reports of the International Panel Climate Change
(IPCC) there is no doubt that climate change has been occurring. All ecosystems on the
earth have been concerned by the effects of climate change. Freshwater communities are
particularly more vulnerable to the climate change because freshwaters are also exposed to
numerous anthropogenic stressors such as hydrological, morphological, connectivity and,
water quality pressures. The main objective of this study is to determine the effects of
climate change on the Salmo trutta distribution under optimistic and pessimistic scenarios
of 2050 and 2080.
Materials & Methods: For this purpose, Species Distribution Modelling (SDM) method
was used. For this purpose, data related to fish observation as well as environmental
variables like elevation, slope, maximum air temperature, range temperature, precipitation
and, maximum width were collected. Then, different models including GLM, GAM, GBM,
RF, CTA, FDA, MARS, ANN and SRE as well as the Ensemble model (in order to reduce
the uncertainty), were used to predict the potential distributions of considered species at the
scale of the Lake Urmia basin and Iran.
Results: The results showed that Salmo trutta populations will decline sharply in the
optimistic scenario in 2050.
Conclusion: Whilst, in a similar scenario, populations of this species will disappear in 2080.
In addition, the populations of Salmo trutta would become extinct in the pessimistic
scenario, including two time scales in 2050 and 2080.