Alternative Approach to the Segmentation of Fishing Fleets

Abstract

The appropriate segmentation of fishing fleets is controversially discussed in fisheries research and management and a variety of approaches has been introduced. The present approach, developed in a pilot study funded by the European Commission – Data Collection Framework (DCF), introduces a standardized multivariate approach for characterizing fisheries fleet segments by hierarchical agglomerative cluster analysis (HAC) of their catch composition. We chose data from 2021 of the Romanian fishing fleet as the basis of our analysis. Statistical analyses were performed using the program RStudio V3.6.1 by running the fleet segmentation package script. The specific indices, tests, and visual validation methods of the package were applied to determine the optimal number of clusters. The procedure was finalized by a post-hoc validation of the clustering result to identify the actual fleet segments. From the basic data, 6 fleet segments for Vessels using active and passive gears (PMP) were highlighted, representing 52 boats, where it was noted that fishing at Rapa whelk (RPW) prevailed with 91.94% of the total catches on the segment, respective 5 fleet segments for Vessels using passive gears (PG) only for vessels <12m, representing 78 vessels where the main catches or recorded at European anchovy (ANE) 25.16%, turbot (TUR) 13.08%, horse mackerel (HMM) 8.75%, thus 130 vessels from two classes of different gears in total. We detected mixed fishing, especially on various assemblages of demersal and pelagic fish, as well as target fishing on demersal and pelagic fish, Rapa whelk, and mussels. For a better understanding of the approach, further research is needed.