Projecting the impact of climatic warming on coldwater fish habitat in Lake Jingpo

Abstract

Climate warming would have a great impact on the water temperature and dissolved oxygen (DO) distribution of lakes in cold regions. It can have an effect on fish populations. To evaluate the effect of climatic change on coldwater fish habitat in cold regions of China, a fish habitat simulation model was developed. The fish habitat simulation model was developed based on the output of A vertical year-round water temperature and dissolved oxygen model. Lake Jingpo in Northeast China was chosen as the representive lake. The coldwater stenothermal fish called Hucho taimen was selected as the indicator species. Constant Values Method and oxythermal habitat parameter method were applied to identify the refuge habitat. The simulation results show that under the future climate scenarios, the uninhabitable space in winter due to low dissolved oxygen in hypolimnion will decrease, the uninhabitable space in summer due to high temperature in epilimnion will expand. Total habitat depth in summer is projected to decrease up to 60%-90%, which means high probability of summer kill. It is projected that multi-year average value of ATDO3 vb (highest average daily TDO3 over variable benchmark period) will have an increase of about 2.5℃, which means Hucho taimen juvenile survival rate will decrease about 35%. In the extreme warm year, the Hucho taimen juvenile survival rate will decrease to 9.0%. The oxythermal habitat parameter method is generic and can be applied to other lakes and reservoirs in Northeast China to identify and compare the refuge habitat of coldwater fishes.