A PROPOSAL OF ECO-ENVIRONMENTAL DIVERSITY INDEX (EED) FOR FISH HABITAT EVALUATION IN SMALL-SCALE RIVERS

Abstract

 This research proposes “Eco-Environmental Diversity index (EED)”, which calculates environmental diversity of depth, velocity, bed condition, and vegetation within fish home range. To incorporate fish preference information into EED, environmental parameters are categorized to represent suitable habitat for different behavioral modes like feeding and/or resting on multiple species and/or growth stages. Through field observations, it had been revealed that EED showed positive relationship with a number of fish species. EED increased in 0.1 resulted in approximately 1 species increase. Streams which had over 0.8 of EED showed high environmental diversity by visual observation. Thus, a new fish habitat evaluation index (EED) has been introduced, which could evaluate small-scale river habitat from the view point of bio-diversity without using habitat suitability index or other fish information during its evaluation process.