Assessing the use of different marine growth zones of adult Atlantic salmon scales for studying marine trophic ecology with stable isotope analysis

Lake Ontario salmon (Salmo salar) were not migratory: A long-standing historical debate solved through stable isotope analysis

“…Historical scales produced δ 13 C values consistent with modern isotopic baseline datasets for freshwater smolt and marine adult salmon scales, respectively293031. Wide separation between δ 13 C and also δ 34 S values of fish with different migratory behaviours indicates that: 1) salmon with δ 13 C and δ 34 S values below −19‰ and +12‰, respectively, completed their entire lifecycle as freshwater residents in Lake Ontario, and 2) salmon with a δ 13 C values above −17‰ and δ 34 S values above +14‰ made a round trip from their natal stream down the St. Lawrence River to the Atlantic Ocean and back over the course of their lives.…”

“…Because the organic components of both bone and scales are composed primarily of Type I collagen, these two sample types are directly comparable, and both represent long-term dietary intake49. Comparative data from modern Atlantic Salmon scales2930 as well as European505152 and North American53 archaeological bones were sourced from previously published studies and are supplemented by new analyses of a single European Atlantic Salmon individual from an Early Christian context from the site of Knowth in Ireland. Morphological analyses of scales from 5 of the 7 nineteenth-century Atlantic Salmon skin mounts were used to provide a second line of evidence for salmon origin and were conducted at the National Marine Fisheries Service (Narragansett, RI, USA) using established methods5455 (Supplementary Information).…”

“…Comparative salmon data from modern scales293031 as well as European505152 and North American53 archaeological bone are denoted by an asterisk. Modern scale δ 13 C data has been adjusted by +1.25‰ to account for historical changes in environmental δ 13 C5960.…”

Chemical archives in fishes beyond otoliths: A review on the use of other body parts as chronological recorders of microchemical constituents for expanding interpretations of environmental, ecological, and life‐history changes

“…The most commonly analyzed stable isotopes (d 13 C and d 15 N) are primarily deposited into basal-layer collagen, but can also become incorporated into the hydroxyapatite matrix (Hutchinson and Trueman 2006;Ventura and Jeppesen 2010). Depending on the research objective, d 13 C and d 15 N has been measured in whole scales (Johnson and Schindler 2012), at targeted circuli to isolate life-history events (Dixon et al 2015), and at the scale's growing edge to describe the most recent activity of an individual fish (Hammond and Savage 2009). Ramsay et al (2012) found that identification of the site-of-origin of Brown Trout (Salmo trutta) improved from 88% to 93% when d 13 C and d 15 N were included as biogeochemical markers in addition to trace elements.…”

Trophic structure of a coastal fish community determined with diet and stable isotope analyses

“…The enriched signals exhibited by A. sapidissima and A. pseudoharengus may reflect their anadromous life histories or recent estuarine foraging, as 15 N increases markedly in coastal environments where the enriched 15 N signal of human sewage and other nutrient sources is persistent throughout the food web (Cabana & Rasmussen, 1996;Hansson et al, 1997;McKinney et al, 2010). In general, the isotopic signatures of migratory species often reflect feeding in multiple areas and habitats (Clément et al, 2014;Dixon et al, 2015). As such, the isotopic signatures of highly mobile species, which integrate multiple months of feeding behaviour, must be interpreted with care (Hobson, 1999;Abrantes & Barnett, 2011).…”