Abstract
For 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.
| Original language | English |
|---|---|
| Pages (from-to) | 2390-2392 |
| Number of pages | 3 |
| Journal | PNAS |
| Volume | 116 |
| Issue number | 7 |
| Early online date | 23 Jan 2019 |
| DOIs | |
| Publication status | Published - 2019 |
Bibliographical note
The authors would like to acknowledge funding from the Horizon 2020 European research projects ClimeFish (grant No. 677039) (to ARB and PGF), an Australian Research Council Future Fellowship (to GP), and the Australian Research Council (grant number DP170104240) (to AA).Data deposition: The data reported in this paper were deposited at Figshare, https://doi.org/10.6084/m9.figshare.7189415.v1.
Keywords
- fish stocks
- fishing
- marine ecology
- marine fish species
- mixed effect models
- ontogenetic deepening
- Animals
- Fisheries
- Conservation of Natural Resources
