Pots vs trammel nets: a catch comparison study in a Mediterranean small-scale fishery

Every animal matters! Evaluating the selectivity of a Mediterranean bottom trawl fishery from a species community perspective

Bottom trawl fisheries often catch several species simultaneously. However, most studies addressing the catch performance and selectivity of a specific trawl focus on a few commercially important or most vulnerable species requiring management measures. By contrast, the present study considers the multispecies nature of Mediterranean bottom trawl fisheries through a holistic approach that accounts for the full species community in the catches. Specifically, we evaluated and compared the catch performance of the two codends allowed for this fishery, made of 40 mm square (SM40) and 50 mm diamond (DM50) meshes. Results showed that 50 and 80% of the catch in weight and count numbers, respectively, consisted of species without commercial value, demonstrating that large proportions of the catch are not considered when using the existing approach to evaluate the ecological impact of the fishing activity. Significant differences in catch profiles between the two codends were observed, especially for two commercial flatfish species, Arnoglossus laterna and Citharus linguatula, with larger contributions in the SM40. Further, the SM40 codend had a significantly higher retention, compared to DM50 codend, for specific sizes of Merluccius merluccius and Mullus barbatus. The outcomes of the study can be useful for the Mediterranean bottom trawl fisheries management.

Application of Light-Emitting Diode Lights to Bluefin Sea Robin (Chelidonichthys spinosus) Catch in Pot Fishery in the South Sea, Korea

The bluefin sea robin (Chelidonichthys spinosus), hereafter BSR, is one of the most important fish species in the South Sea of Korea. The production value of BSR in 2020 was USD 4,733,057. The production volume in Korea has shown an annual mean increase of 8.9% since 2010, but the efficiency of the fishing gear decreased due to excessive use. This has led to a decrease in the profitability of fishery operators, and as compensation, the use of fishing gear has further increased through competitive operations. Alternative measures for improving catch performance and reducing the use of fishing gear are needed. As one such measure, LED (Light-Emitting Diode) lights were attached to the pot, and the effects were determined. The field experiment results showed that the catch of BSR was higher for the experimental groups (n = 10–273) using fishing gear with LED lights (red, green, blue, and white) than for the control group (n = 2) (Kruskal–Wallis test, p < 0.05). Among the experimental groups, the pot with green light achieved the largest catch (n = 273). The use of LED lights was found to enhance the catch efficiency of pot fishing gear for BSR.

Addressing Gaps in Small-Scale Fisheries: A Low-Cost Tracking System

During the last decade vessel-position-recording devices, such as the Vessel Monitoring System and the Automatic Identification System, have increasingly given accurate spatial and quantitative information of industrial fisheries. On the other hand, small-scale fisheries (vessels below 12 m) remain untracked and largely unregulated even though they play an important socio-economic and cultural role in European waters and coastal communities and account for most of the total EU fishing fleet. The typically low-technological capacity of these small-scale fishing boats-for which space and power onboard are often limited-as well their reduced operative range encourage the development of efficient, low-cost, and low-burden tracking solutions. In this context, we designed a cost-effective and scalable prototypic architecture to gather and process positional data from small-scale vessels, making use of a LoRaWAN/cellular network. Data collected by our first installation are presented, as well as its preliminary processing. The emergence of a such low-cost and open-source technology coupled to artificial intelligence could open new opportunities for equipping small-scale vessels, collecting their trajectory data, and estimating their fishing effort (information which has historically not been present). It enables a new monitoring strategy that could effectively include small-scale fleets and support the design of new policies oriented to inform coastal resource and fisheries management.