Fuzzy Comprehensive Evaluation Model for Chinese Sturgeon Habitat Suitability in the Yangtze River

The Chinese sturgeon, a kind of migration or semi-migration fish growing up in coastal water and entering into rivers after sexual maturity, is one of Class I state protection animals. The construction of the Gezhouba dam blocked its migration route to the upstream of the Jinshajiang Riveriquestas a result, Chinese sturgeon established a new spawning ground in the less than 7 km long mainstream of the Yangtze River below the Gezhouba.Based on the research on the main eco-factors influencing growth and reproduction of the Chinese Sturgeon, habitat suitability evaluation system with single goal layer, 2 rule layers, and 10 defined indexes was developed, including water temperature , water depth, substrate, water velocity, water quality, sediment concentration , and egg-predatory fishes. The evaluation and grading criteria for different indexes were presented, and the comprehensive evaluation method for Chinese Sturgeon habitat suitability based on fuzzy mathematics was proposed. The stream habitat for the Chinese Sturgeon was assessed with the model. The model was validated by its application to 6 groups of data, and a habitat satiability model for Chinese Sturgeon is presented.