Residency and movement patterns of Arctic charr Salvelinus alpinus relative to major estuaries.
Estuarine residency and marine movements of 43 anadromous Arctic charr Salvelinus alpinus (mean ± s.d. fork length = 523 ± 97 mm) were examined using acoustic tracking in inner Frobisher Bay (IFB; 63° N; 68° W), Canada, from July to September 2008 and 2009. A mean ± s.d. migration duration of 63 ± 7 days occurred from late June to early September. Detected S. alpinus were either continuously (maximum 34 days) or intermittently present in estuarine zones, on average residing approximately one third of time tracked and returning once every 9 days. Significantly higher estuarine residency during the final 15 migration days suggested that a transition phase may occur prior to freshwater re-entry. Low travel rates during flood tide suggested individuals staged before accessing intertidal and estuarine zones. Although the two main estuaries were c. 22 km apart, 19% of tagged individuals used both. Individuals remained relatively close to freshwater overwintering systems, although late-migration inter-estuarine movements may have indicated natal homing. Approximately half of the individuals exhibited extra-estuarine travel, mostly during mid-migration, but remained within 3 km of shore ranging < 30 km straight line distance (SLD) of either estuary. It was concluded that IFB S. alpinus (1) spent a significant portion of their migration within or adjacent to the estuaries and (2) had a restricted marine distribution within 30 km SLD of the river mouths.
Ocean Tracking Network, Dalhousie University, Biology Department, 1355 Oxford St, Halifax, NS, B3H 4J1, Canada.
A D
AD
Spares
Department of Biology, Acadia University, 33 Westwood Avenue, Wolfville, NS, B4P 2R6, Canada.
M J W
MJ
Stokesbury
Department of Biology, Acadia University, 33 Westwood Avenue, Wolfville, NS, B4P 2R6, Canada.
M J
MJ
Dadswell
Ocean Tracking Network, Dalhousie University, Biology Department, 1355 Oxford St, Halifax, NS, B3H 4J1, Canada.
R K
RK
O'Dor
Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada.
T A
TA
Dick
D000162:Acoustics; D025041:Animal Migration; D000818:Animals; D063366:Estuaries; D005618:Fresh Water; D020957:Nunavut; D045483:Rivers; D055871:Tidal Waves; D014337:Trout
acoustic tracking; estuarine fidelity; marine distribution; tidal phase; travel rate