Survival and Growth of Atlantic Salmon (Salmo salar) Fry Stocked at Varying Densities in the White River, Vermont

1994 ◽  
Vol 51 (10) ◽  
pp. 2164-2169 ◽  
Author(s):  
K. G. Whalen ◽  
G. W. LaBar

Survival and growth of unfed Atlantic salmon (Salmo salar) fry stocked at varying densities (12, 25, 50, and 75 fry∙100 m−2) was evaluated in the White River, a tributary of the Connecticut River in Vermont, using a randomized complete block design. Fry to age-0 parr survival was inversely related to fry stocking density and, in most sampling sections, no significant increases in age-0 parr density were attained by stocking at rates ≥50 fry∙100 m−2. Most age-0 parr ranged in length between 65 and 80 mm; no significant differences in mean age-0 parr length were detected among stocking densities. Greatest age-0 parr production efficiency may be attained by stocking at densities <50 fry∙100 m−2. However, the density of age-0 parr produced from stocking at 12 fry∙100 m−2 may be insufficient to achieve carrying capacity of age-1 parr.


Aquaculture ◽  
1995 ◽  
Vol 130 (4) ◽  
pp. 373-388 ◽  
Author(s):  
Trygve Sigholt ◽  
Magne Staurnes ◽  
Hans J. Jakobsen ◽  
Torbjørn Åsgård


2004 ◽  
Vol 61 (12) ◽  
pp. 2392-2400 ◽  
Author(s):  
Francis Juanes ◽  
Stephen Gephard ◽  
Kenneth F Beland

The Connecticut River historically represented the southernmost extent of the North American range of Atlantic salmon (Salmo salar), but the native population was extirpated 200 years ago by dam construction. An extensive restoration effort has relied upon stock transfers from more northerly rivers, especially the Penobscot River (Maine). Recent work has shown differences in age structure between donor and derivative populations. Here we focus on a related life-history trait, the timing of the adult migration. We examined 23 years of migration timing data collected at two capture locations in the Connecticut River drainage. We found that both dates of first capture and median capture dates have shifted significantly earlier by about 0.5 days·year–1. To conclude whether this is a consequence of local adaptation or a coast-wide effect, we also quantified changes in migration timing of more northerly stocks (in Maine and Canada). We found that the changes in migration timing were not unique to the Connecticut River stock and instead observed coherent patterns in the shift towards earlier peak migration dates across systems. These consistent shifts are correlated with long-term changes in temperature and flow and may represent a response to global climate change.





2003 ◽  
Vol 60 (3) ◽  
pp. 279-285 ◽  
Author(s):  
Matthew J Raffenberg ◽  
Donna L Parrish

Competitive interactions among stream salmonids in resource-limited environments have been linked to reduced success for many species. Few studies have focused on interactions at scales larger than individual fish or stream reach. We chose to focus our study on these larger scales to provide information for managing species that have complex life histories transcending multiple scales. Our objective was to explore age-0 Atlantic salmon (Salmo salar) growth and survival in relation to trout abundance (introduced rainbow (Oncorhynchus mykiss) and native brook (Salvelinus fontinalis) trout) and prey resources at 24 stream reaches across two Vermont watersheds that flow into the Connecticut River. Simple linear and multilinear regressions were conducted on response and predictor variables related to fish and invertebrate prey. Age-0 Atlantic salmon survival was greatest at the site with highest trout abundance; however, no linear relationships to trout abundance were detected possibly because Atlantic salmon growth and survival were highly variable across sites. In contrast, a positive significant multivariate relationship was identified among age-0 Atlantic salmon survival, the abundance of age-1+ brook trout (i.e., 100–130 mm), and benthic prey abundance. These results suggest that stocking streams based on trout abundance may not increase Atlantic salmon growth and survival during the first summer of life.



2009 ◽  
Vol 66 (5) ◽  
pp. 865-870 ◽  
Author(s):  
Rocco C. Cipriano

AbstractCipriano, R. C. 2009. Antibody against infectious salmon anaemia virus among feral Atlantic salmon (Salmo salar). – ICES Journal of Marine Science, 66: 865–870. Archived sera from Atlantic salmon (Salmo salar) that returned to the Penobscot River (Maine), Merrimack River (Massachusetts), and Connecticut River (in Massachusetts) from 1995 to 2002 were analysed for antibodies against infectious salmon anaemia virus (ISAV) using an enzyme-linked immunosorbent assay (ELISA). Up to 60 samples were archived per river system per year. In a given year, the number of fish sampled by ELISA for ISAV antibodies in the Penobscot River ranged from 2.9 to 11.2%, and the range of salmon sampled in the Merrimack River and the Connecticut River was 31.3–100% and 20.0–67.5%, respectively. Archived sera were not available for the 1995 and 2002 year classes from the Connecticut River. In all, 1141 samples were processed; 14 serum samples tested positive for antibodies to ISAV. In the Penobscot River, serum from one fish tested positive in each of the 1995 and 1999 year-class returns, and sera from two fish tested positive in the 1998 returns. In the Merrimack River, sera from four fish tested positive in each of the 1996 and 1997 returns, and sera from two fish were positive in the 2002 return. None of the archived sera from Atlantic salmon that returned to the Connecticut River tested positive.



2005 ◽  
Vol 62 (1) ◽  
pp. 48-57 ◽  
Author(s):  
Brian P Kennedy ◽  
C Page Chamberlain ◽  
Joel D Blum ◽  
Keith H Nislow ◽  
Carol L Folt

We compared the success of using naturally occurring stable isotopes of N, C, and Sr as markers for the rearing locations of juvenile salmon. We analyzed the isotopic signatures (δ15N and δ13C in muscle and scales and 87Sr/86Sr in otoliths) of >200 juvenile Atlantic salmon (Salmo salar) from 12 tributaries of the Connecticut River, USA. Young salmon had distinct N and C signatures 5 weeks after stocking. Signatures were stable over the summer although δ13C varied more than δ15N or 87Sr/86Sr. Scale and muscle signatures were highly correlated, demonstrating the feasibility of nonlethal sampling using fish scales. Some C (but not N) signature from the hatchery was retained in scales of 3-month-old fish, implicating scale annuli as a repository for past C signatures. The δ15N values successfully differentiated fish from tributaries with differences in land use (e.g., agricultural versus forested; ≈ 33% of sites); the δ13C values differentiated fish from 45% of sites. Based upon a discriminant-function analysis, group membership of individuals was correctly predicted in 44.3% (74 of 167) of cases for which both N and C were analyzed. In combination, N and C isotopes differentiated 73% of study sites, which was close to the success of Sr isotopes in the same system (83%).



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