| Guangdong Province is a major fishery province facing the South China Sea.In 2018,the number of marine fishing vessels,the fishing population,the total fishery output,and the total value of fishery economy were 35 694,243 600,1 271 600,and 14.772 billion yuan,respectively,which are all at the forefront of Chia.In the 1980 s,with the increase of fishing power,continuous innovation of operation technology and operation methods,the fishing capacity was severely excessive,and the fishing volume has far exceeded the regeneration of fishery resources.Thus,due to the declining of coastal fishery species,decreasing of biodiversity,and high ecological and environmental pressure,the dominant species are continuously decreasing or even disappearing.The declining of marine fishery resources has become the core issue restricting the sustainable development of fishery economy and fishery economic management in Guangdong.This study compared Beidou ship position data,manually filled fishing log data with electronic fishing log data,and initially determined the credibility of the electronic fishing log data.The status of fishery status,including in the catch structure and distribution of catch rates of major economic species,were evaluated by analyzing the data of electronic fishing log.The result was then used to compared with statistical yearbook data,to evaluate the advantages and disadvantages of this method.The unbalanced production model proposed by Walters & Hilborn was used to calculate the maximum sustainable yield.By analyzing the electronic fishing log of 2018,the total catch of fishery resources in Guangdong Province was predicted.Meanwhile,the carrying status,and compared the carrying capacity of marine fishery resources were calculated with the Fisheries Statistical Yearbook,to analyze the differences between them,as well as the contributing factors.The results could provide technological support for regional management of fishery resources.The results showed that there were extremely significant differences among the operating nets of some fishing vessels(P <0.01),and the repetition rate of operating nets were as low as 35.4%.Overall,the operating fishing area were more reliable than the operating time and operating nets.In order to determine the credibility of the catch recorded in the electronic fishing log,this study analyzed the correlation between the fishing effort and the catch.The result showed that extremely correlation was observed between the operating time and catch of the fourtrawlers(P <0.01).The operating time of a trawler was significantly correlated with the catch(P <0.05),and some of the operating time was extremely significantly correlated with the catch(P <0.01).The credibility of the total catch in the electronic fishing logs reported by different types of fishing vessels were relatively high.Among them,the seine was affected by the power of the light.There was a significant difference between the manually filled fishing logs and the electronic fishing logs.There were significant differences in catches reported by electronic fishing logs from fishing vessels,and there were significant differences in catch structures and catch rates among major economic species.Overall,the total catch reported by the ele ctronic fishing log was more credible.Using the unbalanced surplus production model,the maximum sustainable production of marine fishery resources in Guangdong Province was 168.97 × 104 tons.The fishery statistics yearbook was used to evaluate the fishery resources in Guangdong in 2018,and the electronic fishing log data was used to assess that Guangdong marine fishery resources were in a critical overload state in 2018.The overload rate was 5.55%.With the same number of operating days,In 2018,the power of fishing vessels that should be reduced in Guangdong Province was 6.06 × 104 kW,which was a reduction of 3.5%.Under the condition that the power of fishing vessels remained unchanged,the average annual reduction of fishing vessels is 35 days,so that Guangdong's marine fishery resources are at a load status.On the whole,Guangdong marine fishery resources need attention from various management depart ments in order to provide a theoretical basis for the scientific management of marine fishery in Guangdong Province. |
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