Unravelling the spatial-temporal population structure of Trachurus picturatus across the North-East Atlantic using otolith fingerprinting

• Type: Article in International Scientific Journal
• Date: 2022

Authors

Moreira, C (Author) Other; Froufe, E (Author) Other; Vaz-Pires, P (Author) Other; Triay-Portella, R (Author) Other; Mendez, A (Author) Other; Castro, JP (Author) Other; Correia, AT (Author) ICBAS

Journal

Title: Estuarine, Coastal and Shelf Science

Vol. 272

ISSN: 0272-7714

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 0 Citations

Scopus - 0 Citations

Other information

Authenticus ID: P-00W-J06

DOI: 10.1016/j.ecss.2022.107860

Abstract (EN): The blue jack mackerel Trachurus picturatus is one of the most important pelagic fish captured in the Maca-ronesian islands of the Azores and Madeira. However, in the last years' landings registered substantial decreases. Fluctuations may be related to oscillations in the cohorts' recruitment rates, although no information regarding the species movements and connectivity is available. The present study applies laser ablation inductively coupled-plasma mass spectrometry (LA-ICP-MS) to investigate the otolith chemical fingerprints (core and edge) of three cohorts sampled off the Azores, Madeira, Canaries and Peniche (Portuguese coast) in 2013, 2016 and 2019. Otoliths from juveniles (age 0(+) and 1(+)) and adults (age 3(+)) were examined to infer the scale of geographical variation among fishing grounds and years. Univariate analyses showed significant differences among locations based on Li:Ca, Mg:Ca, Sr:Ca and Ba:Ca concentration ratios. Multi-elemental analyses allocated 70% (2013), 43% (2016) and 43% (2019) of the individuals to their original location based on core elemental fingerprint, and 63% (2013), 75% (2016) and 83% (2019) based on the edge elemental signature. The natal signature suggests that there is some degree of self-recruitment in the fishing grounds and that the sub -populations are connected essentially by dispersal of larvae/juveniles. Furthermore, data suggests that self -recruitment is variable among the cohorts sampled. The discrimination of individuals observed at the time of collection suggests that T. picturatus populations across the north-eastern Atlantic should be regarded as different population units and manage accordingly, as previously observed. Future works should focus on identifying the natal sources of each fishing ground and assess the impact of environmental changes on the distance and di-rection of larval dispersal.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 14