Chin J Plant Ecol ›› 2022, Vol. 46 ›› Issue (10): 1268-1279.DOI: 10.17521/cjpe.2022.0234

Special Issue: 红树林及红树植物 遥感生态学

• Research Articles • Previous Articles     Next Articles

Spatial-temporal dynamics of coastal aquaculture ponds and its impacts on mangrove ecosystems

JIANG Yu-Feng1,2, LI Jing1,2, XIN Rui-Rui1,2, LI Yi1,2,*()   

  1. 1Key Laboratory of Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian 361102, China
    2and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, Guangdong 511458, China
  • Received:2022-06-06 Accepted:2022-09-05 Online:2022-10-20 Published:2022-09-28
  • Contact: *LI Yi(yili@xmu.edu.cn)
  • Supported by:
    National Natural Science Foundation of China(41701205);Fundamental Research Funds for the Central Universities(20720190089);Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Innovative Team Project(311021004)

Abstract:

Aims With increasing anthropogenic activities in coastal areas, human disturbances have been identified as major causes of the decline of coastal mangroves and undemine the sustainable development. Monitoring the spatial-temporal dynamics of typical human activities in mangrove ecosystems and adjacent areas is critical in conservation and restoration of local mangrove ecosystems.

Methods We proposed an object-oriented machine learning method based on seasonal water fluctuations, using Landsat satellite imagery on Google Earth Engine platform. Inundation frequency was incorporated as a classification feature to obtain the spatial pattern of aquaculture ponds, which is concerned as the key driver of degradation and losses of mangroves. We revealed the dynamics of aquaculture ponds at a 30 m-resolution between 1990 and 2020 in China’s coastal regions with mangrove community detected, including Guangdong, Fujian, Zhejiang, Taiwan, Guangxi, and Hainan.

Important findings The total area of coastal aquaculture ponds in 1990 was about 2 963 km2, which increased to 5 200 km2 in 2000 and 5 377 km2 in 2010, and then decreased to 4 805 km2 in 2020. The maximum appeared between 2010 and 2020, but there was a significant regional variation in the changing pattern and peaking time of coastal aquaculture ponds. Coastal aquaculture ponds were mainly concentrated in the region of 21°-24° N (Guangdong and Guangxi). The spatial pattern of mangroves was shown as a staggered arrangement to that of aquaculture ponds. Our results also indicate a symbiotic relationship between aquaculture ponds and mangroves at latitude 21°-22° N, where a large number of mangroves grow along the edges of aquaculture ponds. This special distribution of mangroves and aquaculture ponds leads to a high level of interconnections between these two ecosystems, which can be recognized as the typical areas in exploring the impacts of human activities on mangrove ecosystems. The conversion of mangroves to aquaculture ponds was the primary cause of mangrove loss, which led to the extreme fragmentation and aggregation of mangrove patches in different areas. Our research on the spatial-temporal pattern of coastal aquaculture ponds provides an accurate dataset to assess the impacts of increasing human activities on mangrove ecosystems, and may contribute to the identification of priority restoration area.

Key words: coastal aquaculture ponds, human activities, spatial-temporal analysis, machine learning, inundation frequency