Fisheries Monitoring and Management

Preventing illegal, unreported, and unregulated (IUU) fishing—which depletes fishery resources—is a critical task in international fisheries governance. Many countries operate vessel monitoring systems (VMS) and electronic reporting systems (ERS) to track their fishing vessels, while regional fisheries management organizations (RFMOs) are actively considering the adoption of electronic monitoring systems (EMS). Although ERS and EMS share the same operational goals, differences in their concepts and functions lead to technical and institutional limitations when implemented separately. This study presents a conceptual design of an intelligent electronic monitoring and reporting (I-EMR) system model, which integrates the strengths of both systems to address these limitations and provides a framework for efficient operation. The necessity for the prompt and proactive adoption of such systems is reinforced by recent analyses of global IUU fishing trends, which indicate that IUU activities are not decreasing despite existing monitoring efforts. While empirical validation is beyond the scope of this study, the conceptual framework aims to support transparent management of fishery resources, facilitate real-time monitoring of fishing activities, and serve as a foundation for future pilot testing and operational deployment. Full article

Depensation (or an Allee effect) has recently been detected in stock–recruitment relationships (SRRs) in four Atlantic herring stocks and one Atlantic cod stock using a Bayesian statistical approach. In the present study, we define the Allee effect threshold (B_AET) for these five stocks and propose B_AET as a candidate limit reference point (LRP). We compare B_AET to traditional LRPs based on proportions of equilibrium unfished biomass (B₀) and biomass at maximum sustainable yield (B_MSY) assuming a Beverton–Holt or Ricker SRR with and without depensation, and to the change point from a hockey stick SRR (B_CP). The B_AET for the case studies exceeded 0.2 B₀ and 0.4 B_MSY for three of the case study stocks and exceedances of 0.2 B₀ were more common when the Ricker form of the SRR was assumed. The B_AET estimates for all case studies were less than B_CP. When there is depensation in the SRR, multiple equilibrium states can exist when fishing at a fixed fishing mortality rate (F) because the equilibrium recruits-per-spawner line at a given F can intersect the SRR more than once. The equilibrium biomass is determined by whether there is excess recruitment at the initial projected stock biomass. Estimates of equilibrium F_MSY in the case studies were generally higher for SRRs that included the depensation parameter; however, the long-term F that would lead the stock to crash (F_crash) in the depensation SRRs was often about half the F_crash for SRRs without depensation. When warranted, this study recommends exploration of candidate LRPs from depensatory SRRs, especially if Allee effect thresholds exceed commonly used limits, and simulation testing of management strategies for robustness to depensatory effects. Full article

Global warming has increasingly become a widespread concern of the international community, and one of the key approaches to achieving carbon neutrality goals lies in the carbon sequestration capacity of oceans. Therefore, scientifically and accurately measuring the carbon sink capacity of marine fisheries and studying its spatial effects are particularly crucial for mitigating global climate change. Marine fisheries encompass categories such as fish, shellfish, algae, and crustaceans. Given that marine fisheries-based carbon sinks are non-feed fisheries, with cultivated shellfish and algae being highly representative, this paper primarily focuses on the carbon sink capacity of shellfish and algae as the main assessment criteria for marine fisheries carbon sinks, aiming to apply this research to other countries worldwide to assist in addressing global warming. Thus, based on panel data of shellfish and algae cultivation in nine coastal provinces of China from 2007 to 2021, this paper employs the “removable carbon sink” model to calculate the carbon sink capacity of Chinese marine shellfish and algae aquaculture industry and utilizes the spatial Durbin model to analyze its spatial effects. The research findings are as follows: (1) The spatial distribution of carbon sink capacity in China’s marine shellfish and algae is uneven. (2) Moran’s Index indicates that the carbon sink capacity of marine shellfish and algae exhibits positive spatial correlation, but the degree of spatial agglomeration is unstable. Fujian Province has the highest average carbon sink capacity at 446,451.21 tons, while regions such as Hainan, Hebei, and Jiangsu have relatively lower average carbon sink capacities, with Hainan Province’s being only 3627.57 tons, sufficiently demonstrating the characteristic of uneven spatial distribution. (3) Through decomposition using the spatial Durbin model, it is found that the direct effects of marine shellfish and algae aquaculture production, technological input, technological promotion, and fishery disaster situations are positive, with the result for marine shellfish and algae aquaculture production being 1.617, significantly positive at the 1% level. The result for labor input is −0.847, with a negative direct effect. From the perspective of indirect effects, the indirect effects of marine shellfish and algae aquaculture production, technological input, and technological promotion are positive, with aquaculture production at 1.185, still significantly positive at the 1% level. The result for labor input is −2.140, with a negative indirect effect. These research conclusions provide important references for the formulation of global marine carbon sink-related policies, helping countries optimize resource allocation, strengthen regional collaboration, and increase investment in science and technology. Consequently, they can promote the sustainable development of marine shellfish and algae aquaculture industries, and contribute to enhancing marine carbon sink capacity and achieving global carbon neutrality goals. Full article

Wild oyster reefs have been harvested for centuries and continue to face anthropogenic pressures, including climate change, pollution, and habitat reduction. Oyster aquaculture has grown to supplement depleted wild stocks and strengthen local economies, but development has not occurred at the same rate across all regions. Across the United States, states have a variety of political and cultural influences that impact oyster aquaculture policy, constraining the ability to make direct comparisons among locations that could enhance aquaculture expansion in slower-to-develop states and regions. This research developed a four-part index to compare regulatory, production, and economic attributes of oyster aquaculture among 23 coastal states. The final index score—a summation of the four individual index components—provides a broad integrated view of oyster aquaculture across the U.S. The results indicate that coastal states in the U.S. Mid-Atlantic and New England regions have the greatest number of resource and policy attributes in place to support oyster aquaculture, whereas coastal states in the Gulf of Mexico and Western Pacific region have relatively less in the way of aquaculture-supporting structures. As the oyster aquaculture industry continues to grow in the U.S., results from this study can help organizations involved in oyster aquaculture to make informed decisions to expand permitting, leasing, and production systems, following the model from states who have been active in oyster aquaculture for decades. Mindful and cautious improvements can facilitate sustainable sources of seafood and stable income generation for coastal communities while reducing pressures on wild stocks. Full article

This review examines the animal welfare implications associated with the purse seine fishing method as applied to the following small pelagic species: Atlantic herring (Clupea harengus), Peruvian anchoveta (Engraulis ringens), Atlantic chub mackerel (Scomber colias), and Atlantic mackerel (Scomber scombrus). The analysis is based on synthesized data from the purse seine Method Profile, recently introduced in the catch branch of the fair-fish database—an open-access platform dedicated to compiling, evaluating, and systematically categorizing technical and/or scientific literature on aquatic animal behaviour and welfare. The Method Profile is a novel tool that outlines the commercial relevance of the respective fishing method, its target species, and general operational setup. It provides a structured overview of welfare hazards encountered across the main phases of the fishing process, including prospection, setting, capture, hauling, emersion, gear release, sorting, storage, and stunning and slaughter. In addition, this profile also addresses bycatch and discarding issues as well as environmental hazards associated with the fishing method. Identified welfare concerns in purse seining for the four small pelagic species include high stress levels resulting from intense crowding—primarily leading to hypoxia, mechanical injuries, and mortality—as well as issues related to scooping or pumping fish on board, (live) storage, and the lack of effective stunning and slaughter protocols. Furthermore, the bycatch rate of (undersized) target and diverse non-target species, as well as ghost fishing from abandoned, lost, or discarded gear, pose significant risks requiring effective mitigation. In this review, we critically evaluate factors influencing the welfare outcomes of the four pelagic species caught by purse seine and discuss potential mitigation strategies, such as operational improvements, gear modifications, and management measures. Full article