Evaluating Fishing Capacity Based on DEA and Regression Analysis of China’s Offshore Fishery

The analysis of offshore fishing capacity is of great significance and practical value to the sustainable utilization and conservation of marine fishery resources. Based on the 2004–2020 China Fishery Statistical Yearbook, data envelopment analysis (DEA) was applied for measuring fishing capacity using a number of fishing vessels, total power, total tonnage, and the number of professional fishermen as the input measures and the annual catch as the output measure. Capacity utilization had a calculated range from 80.7 to 100%, and its average is 93.5%. In the first four years of 2003–2007, the excess investment rate of fishing vessels, total tonnage, total power, and fishermen was low (<5%). There was a consistent sharp upward trend in 2007, a gradual downward trend from 2007 to 2015, and an upward trend after reaching a low point in 2015, with the highest gross tonnage of fishing vessels reaching 25.5%. Four regression models that incorporate machine learning algorithms are used, including Lasso, Ridge, KNN, and Polynomial Features. The goodness of fit for the four models was used as the evaluation index, and the offshore annual catch based on the evaluation index was proposed. The forecasting annual catch of the polynomial model can reach 0.98. Furthermore, a comparative simulation of the DEA incorporating the polynomial model was carried out. The results show that DEA can evaluate input factors under the conditions of a given range, and the polynomial model has more advantages in forecasting annual catches. Furthermore, the combined application of DEA and polynomial model was used to analyze and discuss the management policies of China’s offshore fishery, which can provide help and reference for future management.

Fishing capacity of South Baikal in terms of tourism development and limitations on fishing industry

The article considers eco-economic aspects of using the fishing capacity of the basin of South Baikal in the framework of the development of tourism of the coastal territory within Slyudyansky Municipal District of Irkutsk Oblast and within the entire southern Baikal Region. The article proposes to more strongly focus on developing sport and recreational fishing in this most developed area of Lake Baikal. The eco-economic and legal analysis carried out by the authors allows them to conclude that the traditional regulation of the stock of omul in Baikal by determining the total allowable catches and quotas is not effective enough, since it has led to the prohibition of not only industrial but also limitation of sport and recreational fishing for omul. At the same time, there is no reliable data that recreational fishing along the southern coast of Baikal is the reason for the decrease in the total stocks of omul in Baikal. On the contrary, the South Baikal fishing area can become the basis for a more dynamic development of the tourism industry in the region, including such types of it as cognitive tourism, ecological tourism and sports and recreational one. Moreover, it is the South Baikal fishing area and the coastal territory of Slyudyansky Municipal District that can become a testing site for developing more optimal (considering the specifics of various areas of Lake Baikal) ecological approaches to the regulation, rational use and reproduction of the stock of omul in Baikal for the purposes of sport and recreational fishing at Lake Baikal, as well as development of an environmentally friendly tourism industry in the region. The authors propose to review the strategy of fishery development of the stocks of omul at Lake Baikal and remove restrictions on recreational fishing, accompanying this with organizational and legal measures that allow obtaining reliable statistical data on catches. Precisely in this most economically developed area of Lake Baikal it is advisable to practice the organizational and legal mechanisms for the environmentally friendly development of tourist and recreational activities based on the available water bioresources of the unique lake.

Fishing Effort and Associated Catch per Unit Effort for Small-Scale Fisheries in the Mozambique Channel Region: 1950–2016

The Mozambique Channel region in East Africa has diverse marine ecosystems and serves as a migratory corridor for economically important species. Local and foreign industrial fisheries operate in the Mozambique Channel, but regional small-scale fisheries are the crucially important fisheries that provide food security, livelihoods, and economic opportunities for rural coastal communities. This study reconstructed and investigated trends in the fishing effort and catch per unit effort (CPUE) of small-scale marine fisheries in four Exclusive Economic Zones (EEZ) that constitute the Mozambique Channel, i.e., Union of Comoros, Madagascar, Mayotte, and Mozambique, from 1950 to 2016. Effective fishing effort for small-scale fisheries in the form of fishing capacity in kWdays (i.e., kilowatt days) was derived using the number, length, motorization (engine power) by fishing vessels, as well as an approximate human-powered equivalent for shore-based fishers without vessels, as well as days of fishing per year. Effective small-scale fishing effort in the Mozambique Channel increased by nearly 60 times from just over 386,000 kWdays in 1950 to over 23 million kWdays in 2016. Correspondingly, the overall small-scale CPUE, based on previously and independently reconstructed catch data declined by 91% in the region as a whole, from just under 175 kg⋅kWday–1 in the early 1950s to just over 15 kg⋅kWday–1 in recent years. All four EEZs showed the strongest declines in the small-scale CPUE in the earlier decades, driven by motorization and growth in vessel numbers impacting effective fishing effort. Increased motorization combined with a substantial growth in overall vessel numbers were the drivers of the increasing fishing effort and decreasing CPUE, and clearly suggest that continuing to increase the fishing capacity of small-scale fisheries in the absence of effective and restrictive management actions may exacerbate overexploitation risk.

Investment and Decapitalization in the Fishing Industry: The Case of the Spanish Crustacean Freezer Trawler Fleet

The objective of this work is to estimate the capital stock invested in the Spanish freezer trawler fleet dedicated to the capture of crustaceans on the African coast, for the period from 1964 to 2019. The importance of having methods for the correct measurement of the capital invested in a fishing fleet is to be able to express in monetary terms the excess catch capacity, which is a signal of overexploitation of a fishery, that is, the fleet operates at a level of effort or capacity higher than the minimum amount required to capture the desired quantity at the lowest possible cost. Following a methodology based on the permanent inventory method, we obtained a model that explains the construction value of a fishing vessel as a function of its technical characteristics. The market value in successive sales was estimated as a function of the construction value, the age of vessel and other variables. In this way, we estimated the value that the market assigns to the possible increases in individual fishing capacity and the decrease in value derived from the technical obsolescence of the vessels. Finally, we calculated the gross and net investment series and net capital stock.

KAJIAN ASPEK TEKNIS PERIKANAN GILLNET BERBASIS EAFM (ECOSYSTEM APPROACH TO FISHERIES MANAGEMENT) DI PERAIRAN DUMAI

The local government law regulated the management of 0 – 12 miles waters carried out by the province so that fishermen can operate their fishing gear without differentiating districts. Catch fishing was not limited to one kind of fishing gear and it caused the increasing of fishing capacity. The limited area of fishing with the distance of 2 miles from coast can caused fisheries utilization resources was not balanced. Therefore this study needed to be conducted to assess the status of development of gillnet fishing activities in Dumai waters. Data was collected by conducting interviews in the form of: fishing units, selectivity, sustainability of function and size of fishing vessel with legal documents, and modification of fishing gear. The data results based on 5 fishing technical aspects explained that the fishing utilization of gillnet still could be developed. However, the data of fishing vessel documents have to be well recorded according to the reality so that government could develop the responsible fishing activities.