Assessment of the Habitat Quality of Offshore Area in Tongzhou Bay, China: Using Benthic Habitat Suitability and the InVEST Model

Abstract

Coastal zones, and in particular offshore areas, are coming under ever-increasing pressure from human development. Therefore, the evaluation of habitat quality is of vital importance for management of coastal zones. The InVEST model adopts a multi-module and multi-level design form, which has the advantages of strong visualization and fast calculation. As a result, this study used the InVEST-Habitat quality (HQ) model to assess the habitat quality of the Tongzhou Bay offshore area. Development activities were included in the classification of habitat types and the benthic habitat suitability index was used to describe the spatial variation in habitat quality of the offshore area. The results showed that the methodological approach mentioned above achieved a more detailed assessment of the spatial variation in habitat quality. The empirical model constructed based on the relationship between the Shannon–Weiner index and environmental factors performed well in revealing the suitability of habitat, with the regression equation showing an R2 of 0.57 and R2 of 0.5 significant at level of p < 0.05. The habitat suitability of Tongzhou Bay water was mainly influenced by aquaculture and industrial sea use. The habitat quality of Tongzhou Bay was relatively low due to disturbance by coastal development and a low water habitat suitability. The distribution of habitat quality in Tongzhou Bay was uneven and improved with the increase of the distance from the coast. Improvement of the habitat quality of Tongzhou Bay requires strict control of sea reclamation, optimization of the structure of offshore aquaculture, improvements to water quality and habitat suitability, and strengthening of the protection of areas of high habitat quality. This study provides a novel method for evaluating habitat quality of offshore areas.