Fin tissues as surrogates of white muscle when assessing carbon and nitrogen stable isotope levels for Arctic and brook char

• Published in: Environmental biology of fishes 2014-06, Vol.97 (6), p.627-633
• Main Authors: Curry, R. Allen, Gautreau, Mark D, Culp, Joseph M
• Format: Article
• Language: English
• Subjects: Agnatha. Pisces; Animal and plant ecology; Animal Systematics/Taxonomy/Biogeography; Animal, plant and microbial ecology; Animals; Arctic zone; Autoecology; Biological and medical sciences; Biomedical and Life Sciences; Carbon; Cold regions; drainage; Environment; Fish; Fontinalis; Fresh water ecosystems; Freshwater & Marine Ecology; Fundamental and applied biological sciences. Psychology; Isotopes; Life Sciences; Marine environment; Nature Conservation; Nitrogen; Salvelinus alpinus; Salvelinus fontinalis; Stable isotopes; Synecology; Tissues; Vertebrata; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution; watersheds; Zoology
• ISSN: 0378-1909; 1573-5133
• DOI: 10.1007/s10641-013-0165-z

Arctic char (Salvelinus alpinus) are a fish species ubiquitous to the fresh waters of Arctic region and brook char (Salvelinus fontinalis) are similarly common across the sub-Arctic region of eastern Canada. Populations can be small in numbers, especially farther north thus it is important to develop non-lethal methods of sampling these fish to minimize the invasiveness and impact of scientific research. We examined the stable isotopes of nitrogen and carbon in white muscle, caudal fin, and adipose fin tissues of Arctic char and brook char (S. fontinalis) from northern Quebec and Labrador, Canada. Our results revealed several broad conclusions. First, differences among muscle, caudal fin, and adipose fin tissues were ~1 ‰ for freshwater Arctic and brook char. Second, the two species within the same drainage had similar stable isotope levels and tissue differences. Third, anadromous Arctic char show similar, non-significant differences among these tissues for δ¹⁵N, but muscle δ¹³C was highly enriched. Fourth, the stable isotope levels and tissue differences were the same for anadromous Arctic char from two watersheds where char use distinctly different ocean environments. Overall, it appears that caudal fin tissue in particular is a useful surrogate for white muscle δ¹³C and δ¹⁵N levels for Arctic and brook char in this region and thus, a non-lethal collection of a small sample of caudal fin tissue will provide an accurate measure of white muscle isotope levels.