Prediction model of marine catch based on GM (1, N) in the Indian Ocean

The Indian Ocean is an important marine fishery production area, and its marine catch has shown a continuously increasing trend in the past several decades. The scientific prediction of the catch trend in the future is of great significance to the development of China's pelagic fishery. Based on the catch data of Indian Ocean from 2000 to 2016, the main catch categories affecting the total catch were analyzed by using the grey system theory and method, and the catch of 2017 to 2018 were used for GM (1, N) models verification. Based on the optimal GM (1, N) , the total catch in the Indian Ocean from 2019 to 2025 was predicted. According to the study, the main categories that affect the total catch in the Indian Ocean were bottom fish, crustacean, pelagic fish, other marine fish and cephalopod, and their grey correlation degree is above 0.70. The optimal prediction model is GM (1, 5) and GM (1, 6) , the average relative error is 1.83% and 1.90% respectively, and the grey correlation degree is above 0.9. The average relative errors for 2017 and 2018 are 3.78% and 3.42% respectively. The total catch projections for 2019–2020 and 2021–2025 in the Indian Ocean are 11.86-12.90 million tons and 12.27-13.24 million tons, respectively. The main increases in catches are likely to come from pelagic, cephalopod and bottom fish. The study concluded that the growth of the total catch in the Indian Ocean during the 14th five-year plan period would limited, with a total increase of less than 0.8 million tons, and that the total catch be basically at the stage of full development. It is recommended that the scale of fisheries development should be strictly controlled in the future in order to ensure the sustainable development of marine fisheries and the sustainable utilization of fishery resources in the Indian Ocean.