Quantifying thermal effects on contemporary growth variability to predict responses to climate change in northern rock sole (Lepidopsetta polyxystra)

• Published in: Canadian journal of fisheries and aquatic sciences 2010-01, Vol.67 (1), p.97-107
• Main Authors: Hurst, Thomas P, Abookire, Alisa A, Knoth, Brian
• Format: Article
• Language: English
• Subjects: Animal reproduction; Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Climate change; Climatology. Bioclimatology. Climate change; Correlation analysis; Density dependence; Earth, ocean, space; Effects; Environmental control; Exact sciences and technology; Exploitation and management of natural biological resources (hunting, fishing and exploited populations survey, etc.); External geophysics; Fish; Fish populations; Fisheries; Fundamental and applied biological sciences. Psychology; Growth rate; Larval development; Lepidopsetta polyxystra; Marine; Marine fish; Marine productivity; Meteorology; Nursery grounds; Physiological aspects; Rocks; Spawning; Temperature; Water temperature
• ISSN: 0706-652X; 1205-7533
• DOI: 10.1139/F09-171

Understanding the causes of contemporary variation in growth rates can offer insights into the likely consequences of climate change for growth and recruitment of coastal marine fishes. We examined the growth dynamics of age-0 northern rock sole ( Lepidopsetta polyxystra ) over four years in three nurseries at Kodiak Island, Alaska, USA. Following the settlement period, fish were sampled monthly (July-October) with a 3 m beam trawl at fixed-position transects. Postsettlement sizes were positively related to temperatures during the spawning and larval periods, suggesting environmental control of spawning or settlement timing. Summer growth on the nursery grounds varied significantly among sites and years (mean size 32.8-63.1 mm in mid-September), with the Holiday Beach site consistently supporting the fastest growth rates. Contrary to expectations of density dependence and thermal regulation, nursery ground growth rates were not significantly correlated with fish density or water temperatures. The minor contribution of thermal variation to growth rates appears related to the conservative growth strategy and low thermal sensitivity of northern rock sole. These results suggest that climate changes influencing spawning time and larval growth may have larger impacts on first-year growth and recruitment of this species than temperature effects on the growth of nursery-resident juveniles.