Analysis of Changes in Aquaculture Ponds in Liaodong Bay From 1985 to 2020

Abstract

Liaodong Bay is an important aquaculture base in the northernmost part of China’s sea area. With the rapid development of aquaculture and the rapid expansion of aquaculture ponds, the ecological environment of many aquaculture areas has been deteriorating, which has brought about a series of ecological and environmental problems, so it is necessary to carry out rapid, accurate, and sustained monitoring of the near-coastal aquaculture areas. In this study, we utilized the Google Earth Engine (GEE) platform to extract the spatial distribution and temporal distribution information of aquaculture ponds in Liaodong Bay in a long-term time series from 1985 to 2020 using Landsat image data, which was validated by accuracy assessment, and then analyzed the distribution, area change, and spatial and temporal evolution of aquaculture ponds. The results showed that the spatial distribution of aquaculture ponds in Liaodong Bay was uneven, with hotspots mainly located in Linghai, Jinzhou; Gaizhou, Yingkou; Suizhong, Huludao; Changxingdao, Dalian; and part of Panjin. The process of change in the area of aquaculture ponds in Liaodong Bay is divided into three phases: the fluctuation period of 1985–1995, the rapid expansion period of 1995–2010, and the stabilization period of 2010–2020, and the aquaculture ponds in Liaodong Bay show a shift from continuous expansion to sustainable development, from quantitative growth to quality and efficiency, and from single-emphasis on production to energy-saving and environmentally friendly modes. The results of the study are expected to reveal the current situation, dynamics and development pressure of aquaculture ponds in the coastal area of Liaodong Bay, and to provide information support and decision support for scientific planning of aquaculture in Liaodong Bay.