Whole body-element composition of Atlantic salmon Salmo salar influenced by migration direction and life stage in three distinct populations.
Body-element content was measured for three life stages of wild Atlantic salmon Salmo salar from three distinct Newfoundland populations as individuals crossed between freshwater and marine ecosystems. Life stage explained most of the variation in observed body-element concentration whereas river of capture explained very little variation. Element composition of downstream migrating post-spawn adults (i.e. kelts) and juvenile smolts were similar and the composition of these two life stages strongly differed from adults migrating upstream to spawn. Low variation within life stages and across populations suggests that S. salar may exert rheostatic control of their body-element composition. Additionally, observed differences in trace element concentration between adults and other life stages were probably driven by the high carbon concentration in adults because abundant elements, such as carbon, can strongly influence the observed concentrations of less abundant elements. Thus, understanding variation among individuals in trace elements composition requires the measurement of more abundant elements. Changes in element concentration with ontogeny have important consequences the role of fishes in ecosystem nutrient cycling and should receive further attention.
Department of Biology, Memorial University of Newfoundland, 232 Elizabeth Ave., St John's, NL, A1B 3X9, Canada. jd.ebel@mun.ca.
J D
JD
Ebel
Department of Biology, Memorial University of Newfoundland, 232 Elizabeth Ave., St John's, NL, A1B 3X9, Canada.
S J
SJ
Leroux
Fisheries and Oceans Canada, Science Branch, 80 East White Hills Road, St John's, NL, A1C 5X1, Canada.
M J
MJ
Robertson
Fisheries and Oceans Canada, Science Branch, 80 East White Hills Road, St John's, NL, A1C 5X1, Canada.
J B
JB
Dempson
D025041:Animal Migration; D000818:Animals; D049628:Body Size; D017753:Ecosystem; D009523:Newfoundland and Labrador; D045483:Rivers; D020317:Salmo salar / Q000254:growth & development / Q000378:metabolism*
Newfoundland; anadromy; nutrient; ontogeny; rheostasis; stoichiometry