Monitoring dolphinfish catches and diel assemblage fluctuations using eDNA at fish-aggregating devices

Marinchel, N, Galli, S, Mifsud, J, Albanozzo, M, Camilleri, K, Ceriola, L, Labriola, MS, Maiello, G ORCID: 0000-0002-0431-4205, Carpentieri, P, Mariani, S ORCID: 0000-0002-5329-0553 and Russo, T (2026) Monitoring dolphinfish catches and diel assemblage fluctuations using eDNA at fish-aggregating devices. Ecosphere, 17 (6). ISSN 2150-8925

Preview

Text Ecosphere - 2026 - Marinchel - Monitoring dolphinfish catches and diel assemblage fluctuations using eDNA at.pdf - Published Version Available under License Creative Commons Attribution. Download (7MB) | Preview

Abstract

Fish-aggregating devices (FADs) are man-made objects designed to attract fish, with the aim of facilitating spatially heterogeneous aggregations of marine species. These objects influence the structure of pelagic fisheries, consequently affecting fish distributions and interactions. One of the most iconic epipelagic species targeted using FADs is dolphinfish (Coryphaena hippurus), which has high commercial value in the Mediterranean Sea. However, the interactions between dolphinfish and FADs are still poorly understood, and the composition of fish assemblages attracted to these devices remains poorly characterized. Environmental DNA (eDNA) metabarcoding has emerged as a powerful tool for fisheries management. Here, we employed passive eDNA samplers (i.e., metaprobes) to collect information on the fish assemblages around five FADs in Maltese waters during a dolphinfish fishing day in January 2023. Samples were gathered during different diel phases: Three stations were sampled in the diurnal phase, while two were sampled during the crepuscular-evening phase. Through the amplification of the mitochondrial 12S gene region (Elas02 primers), we explored the relationship between C. hippurus-caught biomass and transformed read counts and investigated the composition of fish assemblages associated with FADs. A positive relationship was found between eDNA-transformed read counts of dolphinfish and their biomass (linear regression model, R2 = 0.62, p < 0.05). Fish assemblages attracted by FADs were found to significantly change between diurnal and crepuscular-evening phases. Moreover, the indicator species analysis identified four species as being indicative of the crepuscular-evening phase (Diaphus rafinesquii, Hygophum benoiti, Hygophum hygomii, and Lampanyctus pusillus). The similarity percentage (SIMPER) test identified seven species as the main contributors to variations in dolphinfish-caught biomass. Of these, four species (Sardina pilchardus, Trachurus trachurus, Engraulis encrasicolus, and Chelon labrosus) showed a significant relationship between their transformed read counts and dolphinfish-caught biomass. Despite the small number of samples, this study highlighted the potential of low-cost passive eDNA collection to assess the composition of pelagic fish assemblages around FADs. This improves our understanding of the ecological dynamics around these fishing gears and helps to optimize fishing efficiency, thereby promoting sustainable fisheries management strategies.

Item Type:	Article
Uncontrolled Keywords:	Central Mediterranean Sea; Coryphaena hippurus; diel phases; eDNA metabarcoding; fish assemblages; fish-aggregating devices; 41 Environmental Sciences; 3103 Ecology; 4104 Environmental Management; 31 Biological Sciences; 14 Life Below Water; 0501 Ecological Applications; 0602 Ecology; 0608 Zoology; 3103 Ecology; 4102 Ecological applications
Subjects:	Q Science > QL Zoology T Technology > T Technology (General)
Divisions:	Biological and Environmental Sciences (from Sep 19)
Publisher:	Wiley
Date of acceptance:	18 February 2026
Date of first compliant Open Access:	14 July 2026
Date Deposited:	14 Jul 2026 15:09
Last Modified:	14 Jul 2026 15:09
DOI or ID number:	10.1002/ecs2.70645
URI:	https://researchonline.ljmu.ac.uk/id/eprint/29016

View Item