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Ontogenetic deepening of Northeast Atlantic fish stocks is not driven by fishing exploitation
journal contribution
posted on 2023-05-20, 00:16 authored by Baudron, AR, Gretta PeclGretta Pecl, Caleb GardnerCaleb Gardner, Fernandes, PG, Asta AudzijonyteAsta AudzijonyteFor many marine fish species, the average size of individuals increases with depth. This phenomenon, first described a century ago, is known as ontogenetic deepening (1, 2). Several mechanisms have been proposed to explain it: optimal foraging; predation avoidance; and different optimal growth temperature for larger individuals, causing them to seek deeper and cooler waters to optimize growth and reproduction (3). In their recent paper in PNAS, Frank et al. (4) suggest an alternative explanation. They examined age-structured data from Atlantic cod (Gadus morhua) on the eastern Scotian Shelf, a stock that has experienced successive periods of intense, and absence of, fishing. In their study, fishing explained 72% of the variation in the observed age-related deepening, with the remaining variability attributed to ontogenetic deepening. They conclude that higher abundances of large fish in deeper waters is an artifact of greater fishing intensity at shallower depths and question whether ontogenetic deepening is a real ecological phenomenon.
History
Publication title
Proceedings of the National Academy of Sciences of The United States of AmericaVolume
116Issue
7Pagination
2390-2392ISSN
1091-6490Department/School
Institute for Marine and Antarctic StudiesPublisher
Natl Acad SciencesPlace of publication
2101 Constitution Ave Nw, Washington, USA, Dc, 20418Rights statement
Copyright 2019 The AuthorsRepository Status
- Restricted