Habitat suitability of Scapharca subcrenata (Lischke) in the shallow water of the Xiaoheishan Island

Abstract

The habitat suitability index (HSI) model was used to identify potential sites for sustainable restoration of ark shell, Scapharca subcrenata (Lischke), in the shallow water of Xiaoheishan Island, using a geographic information system framework. The seven input variables of the HSI model were sediment composition, water temperature, salinity, dissolved oxygen, water depth, pH, and ammonia. A non-linear suitability function for each variable factor was used to transform the value into a normalized quality index ranging from 0 (nonsuitability) to 1 (best suitability). In present study, the analysis of habitat suitability was conducted for four seasons respectively. The majority of the study area has a high HSI value (>0.6) year round, which implies a strong suitability for restoration, with the optimal habitat located on the eastern side of the island. Correspondence analysis indicated that water temperature was the main factor causing seasonal variation, while sediment composition and water depth were the two major reasons for the differences in sites. The results of this work could provide support for restoration decision making through identification of potential sites for sustainable establishment of S. subcrenata.