Sub-lethal exposure to ultraviolet radiation reduces prey consumption by Atlantic cod larvae (Gadus morhua)

• Published in: Marine biology 2013-10, Vol.160 (10), p.2591-2596
• Main Authors: Fukunishi, Yuichi, Browman, Howard I, Durif, Caroline M. F, Bjelland, Reidun M, Shema, Steven D, Fields, David M, Skiftesvik, Anne Berit
• Format: Article
• Language: English
• Subjects: Agnatha. Pisces; Animal and plant ecology; Animal populations; Animal, plant and microbial ecology; Biological and medical sciences; Biomedical and Life Sciences; Cod; digestive system; energy; Exposure; fish larvae; Fishes; Foraging behavior; Freshwater & Marine Ecology; Fundamental and applied biological sciences. Psychology; Gadus morhua; Health aspects; Larvae; Lethal effects; Life Sciences; Marine; Marine & Freshwater Sciences; Marine biology; Marine fish; Microbiology; mortality; Oceanography; Original Paper; Ozone depletion; Predation; Prey; Rotifera; Sea water ecosystems; sublethal effects; Synecology; Ultraviolet radiation; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution; Zoology
• ISSN: 0025-3162; 1432-1793
• DOI: 10.1007/s00227-013-2253-1

Levels of ultraviolet-B radiation (UV-B: 280–315 nm) reaching the earth’s surface have increased over the past few decades due to ozone depletion. It is well documented that exposure to UV-B radiation increases mortality in marine fish larvae. However, few studies have examined sub-lethal effects of UV-B radiation such as, for example, the possibility that it affects prey consumption by fish larvae. Atlantic cod larvae were exposed to a sub-lethal level of ultraviolet-B radiation (UV-B: 280–315 nm) for 15 h. After the exposure, rotifers (4/mL) were fed to cod larvae at three different post-exposure intervals (20 min, 3 and 6 h). Trials were replicated three times for each post-exposure interval. The number of rotifers in the gut and the percent of empty guts (number of fish with empty gut/number of fish examined × 100) were analyzed. Results were compared to those of unexposed fish (the control treatment). UV-B exposed cod larvae had consumed significantly fewer rotifers than control fish at all post-exposure intervals. There was no significant difference in the frequency of empty guts between fish in the UV-B treatment versus fish in the control treatment at any of the post-exposure time points (although the difference at 20 min post-exposure was borderline significant). These observations suggest that cod larvae exposed to sub-lethal levels of UV-B have lower net energy gain which may lead to reduced growth rate and possibly poorer survival.