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An hypoxia-tolerant flatfish: consequences of sustained stress on the slender sole Lyopsetta exilis (Pleuronectidae) in the context of a changing ocean
- Source :
- Journal of Fish Biology
- Publication Year :
- 2019
-
Abstract
- Slender sole Lyopsetta exilis is an abundant groundfish on the continental shelf and inner waters of British Columbia, Canada, where it reaches a maximum standard length of 44 cm. Benthic image surveys coupled with oxygen measurements in Saanich Inlet document a dense population in bottom conditions near anoxia (0.03 ml l−1 oxygen) where diel migrating zooplankton intersect the bottom; we confirm this species is a planktivore, which limits its depth range to the base of the migration layer. In a comparison with slender sole from a nearby well‐oxygenated habitat, several probable effects of living in severe hypoxia emerge: both sexes are significantly smaller in Saanich and the sex ratio is male‐skewed. Otoliths from the Saanich fish were difficult to read due to many checks, but both sexes were smaller at age with the largest female (20 cm) from the hypoxia zone registering 17 years. Hypoxia appears to have a direct consequence on growth despite good food supply in this productive basin. Hyperventilation, a low metabolic rate and a very low critical oxygen tension help this fish regulate oxygen uptake in severely hypoxic conditions; it will be particularly resilient as the incidence of hypoxia increases on the continental shelf. Data from small‐mesh bottom‐trawl surveys over four decades reveal an increase in mean annual catch per unit effort in southern regions of the province, including the outer shelf and the Strait of Georgia. The California Cooperative Oceanic Fisheries Investigations (CalCOFI) ichthyoplankton database records a general decline in fish larvae on the Oregon–California shelf since 1990, but slender sole larvae are increasing there, as they are in the Strait of Georgia. We project that the slender sole will gain relative benefits in the future warming, deoxygenated northeast Pacific Ocean.
- Subjects :
- 0106 biological sciences
Saanich Inlet
Climate Change
NE Pacific Ocean
Population
Population Dynamics
population change
Flounder
growth response
Aquatic Science
010603 evolutionary biology
01 natural sciences
Otolithic Membrane
Stress, Physiological
Regular Paper
Animals
Body Size
14. Life underwater
Sex Ratio
education
Hypoxia
Planktivore
oxygen stress
Ecology, Evolution, Behavior and Systematics
Ecosystem
geography
education.field_of_study
geography.geographical_feature_category
Pacific Ocean
biology
British Columbia
Continental shelf
010604 marine biology & hydrobiology
fungi
Regular Papers
Hypoxia (environmental)
Water
Ichthyoplankton
biology.organism_classification
Oxygen tension
Oxygen
Oceanography
otoliths
Groundfish
Slender sole
Subjects
Details
- ISSN :
- 10958649
- Volume :
- 96
- Issue :
- 2
- Database :
- OpenAIRE
- Journal :
- Journal of fish biology
- Accession number :
- edsair.doi.dedup.....0336e70a009ae77d5545e2d02c743466