Detection the Expansion of Marine Aquaculture in Sansha Bay by Remote Sensing

Monitoring the marine aquaculture plays an important role in the management of marine fisheries, and also provides a valid method to evaluate the expansion intensity of the mariculture. In this context, different periods (2003, 2005, 2008, 2011, 2013, 2014 and 2016) of Landsat satellite data were collected and supervised classification method support vector machine (SVM) method was applied to extracted marine aquaculture in the Sansha Bay. Finally, different expansion indicators were used to evaluate the expansion intensity of mariculture in the study area. The results showed that: (1) the area of cage and algae culture increased rapidly, with the annual rates of expansion in 2.2×10
⁴
km
²
and 9.3×10
⁴
km
²
respectively from 2003 to 2016; (2) The total marine aquaculture reached 160×10
⁴
km
²
in 2016, more than 21.2% of the planned mariculture; (3) Cage culture expanded from the coast of mainland and island to the deep sea, but the algae culture expanded more obviously and almost covered the sea, and the expansion intensity of cage and algae culture varied greatly at different periods.