Environmental influences on an exploited anadromous Arctic charr stock in Labrador

Abstract

Arctic charr Salvelinus alpinus at Nain, Labrador, were influenced by recent variability in measured environmental variables and able to mitigate partially the effects of past conditions in a single year. Weather conditions prevailing during the first winter and sea migration life-stages also exerted significant influence on measured age and weight characteristics and are argued to play a role in determining the population dynamics of exploited stocks. 2000 The Fisheries Society of the British Isles

Resilience and stability of north Labrador Arctic charr, Salvelinus alpinus, subject to exploitation and environmental variability

“…Thus, in recent years, possibly as a result of reduced fishing 1977 -1981 1982 -1986 1987 -1991 1992 -1996 1997 -2001 2002 -2005 Table 2 Summary of stomach contents of anadromous Arctic charr sampled from the Voisey and Nain (inshore and offshore zone) stock complexes in north Labrador Relative importance of prey organisms (% by weight) Voisey stock complex Nain-inshore zone Nain-offshore zone Prey Organism 1997-19992003-2005-19992003-2005-19992003-2005 Pisces ( Data are presented on a percent wet weight basis for charr greater than or equal to 300 mm in fork length, and summarized in three-year intervals since the early 1990s, mean weights as well as lengthat-age, have begun to return to values not recorded since the mid-to-late 1980s. It is uncertain, however, whether the observed changes in population structure are simply a direct result of reduced exploitation on the anadromous stocks, or a combination of reduced fishing plus the influence of environmental conditions that were previously shown also to have affected measured stock characteristics of Nain charr (Power et al 2000). In the latter study summer sea-surface temperatures, and summer precipitation and temperature lagged 4 years, were shown to have a strong influence on patterns observed in trends in mean weight.…”

“…Details pertaining to sampling programs and commercial landings information are provided by Dempson (1995) and Power et al (2000). Previously, limited biological sampling was carried out in 1953 (Andrews and Lear 1956) and again in 1973and 1974(Coady and Best 1976.…”

Changes in growth patterns of wild Arctic charr (Salvelinus alpinus (L.)) in response to fluctuating environmental conditions

“…In addition to the impacts on marine species, changes were also observed in stock characteristics of anadromous Arctic charr (Salvelinus alpinus, Linneaus) in the Labrador region (Dempson, 1995;Power et al, 2000;Dempson et al, 2002Dempson et al, , 2008. In particular, significant relationships between climatic variables and the mean size and age of Arctic charr captured on the Labrador shelf were noted for exploited stock complexes in the region (e.g.…”

“…The Station 27 database is one of the most consistent, long-term time series of marine climatic information available for the coastal Labrador region, and has been used in numerous other studies to investigate responses of biota in the northwest Atlantic to variations in climatic and oceanographic conditions (e.g. deYoung & Rose, 1993;Hutchings & Myers, 1994, Montevecchi & Myers, 1997Colbourne et al, 1997b;Power et al, 2000;Carscadden et al, 2001;Colbourne & Anderson, 2003).…”

“…In particular, significant relationships between climatic variables and the mean size and age of Arctic charr captured on the Labrador shelf were noted for exploited stock complexes in the region (e.g. Dempson, 1995;Power et al, 2000;Dempson et al, 2008). Trends were established primarily between year-to-year variability in temperature and the mean size of charr in annual catches.…”