Premium
Influence of Short‐Term Estuarine Rearing on the Ocean Survival and Size at Return of Coho Salmon in Southeastern Alaska
Author(s) -
Linley Timothy J.
Publication year - 2001
Publication title -
north american journal of aquaculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 41
eISSN - 1548-8454
pISSN - 1522-2055
DOI - 10.1577/1548-8454(2001)063<0306:ioster>2.0.co;2
Subject(s) - biology , term (time) , estuary , fishery , oceanography , geology , physics , quantum mechanics
Hatchery smolts of coho salmon Oncorhynchus kisutch , cultured for 2–5 weeks in estuarine net‐pens, were compared with those released directly from freshwater to determine whether short‐term seawater rearing would influence their ocean survival or size at return. Samples of each experimental group were marked with coded wire tags before release, and ocean survival and size at return were estimated from tag recoveries. Releases of all experimental groups were timed to coincide with the peak emigration of wild smolts from local streams. After accounting for year‐class variation, the duration of estuarine net‐pen rearing had a significant positive effect on the rate ( P = 0.012) and size ( P < 0.001) of returning adults. Smolt size at release did not significantly affect either survival or size at return ( P ≥ 0.34). The results suggest that short‐term estuarine rearing before release may ameliorate the effects of osmotic stress on growth and survival during the critical period of seawater adaptation. This approach may have utility for enhancement programs that have access to marine sites because it can provide for increased smolt production and higher ocean survival, resulting in a possibly greater biomass of returning adults.