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Survival, Growth, and Smolt Production of Atlantic Salmon Stocked as Fry in a Southern New England Stream
Author(s) -
Orciari Robert D.,
Leonard Gerald H.,
Mysling Donald J.,
Schluntz Eric C.
Publication year - 1994
Publication title -
north american journal of fisheries management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.587
H-Index - 72
eISSN - 1548-8675
pISSN - 0275-5947
DOI - 10.1577/1548-8675(1994)014<0588:sgaspo>2.3.co;2
Subject(s) - stocking , salmo , fishery , intraspecific competition , population , biology , fish <actinopterygii> , icelandic , geography , ecology , demography , linguistics , philosophy , sociology
The performance of Atlantic salmon Salmo salar stocked as fry was assessed in a third‐order stream of the lower Connecticut River system. Stocking densities of 100–150 unfed fry per 100 m 2 of stream area were tested for their ability to maximize smolt production. Because the Connecticut River no longer had a natural population of Atlantic salmon, fry originating from the Penobscot River of Maine were stocked in 1982, 1984, and 1985. In 1983, the Penobscot strain was unavailable and fry originating from Iceland were used instead. Although stocking conditions were not always favorable, an average of 27% of Penobscot fry survived to the fall age‐0 pan stage. In contrast, only 2% of Icelandic fry survived to this stage, The low survival of Icelandic fry may have been due to their smaller total lengths and to intraspecific competition from an abundant population of yearlings that had been stocked in 1982. However, these factors would not have influenced summer‐to‐fall survival of yearlings, which was also lower for Icelandic fish (41%) than for Penobscot fish (59–62%). The lower survival of Icelandic parr suggests that this geographically distant strain may not be suited for fry stocking in southern New England. The more regional Penobscot strain performed very well; on average, stocking 125 fry/100 m 2 yielded 34 fall age‐0 parr, 10 fall age‐1 parr, and 3.6 smolts (87% age 2) per 100 m 2 . By the end of the growing seasons, Penobscot fry that were stocked at an average total length of 29 mm averaged 89 mm at age 0, 150 mm at age l, and 178 mm at age 2. As smolts, they averaged 158 mm at age l, 186 mm at age 2, and 202 mm at age 3. Because our limited data suggested density‐dependent effects on growth and survival, the high production of smolts may have been at the expense of fry‐to‐smolt survival. Stocking at high densities may not be appropriate when survival rates of limited numbers of fry are to be optimized. But when the management objective is to produce Atlantic salmon smolts at near‐maximum levels in southern New England streams, stocking fry at densities of 100–125/100 m 2 should produce 3–4 Atlantic salmon smolts per 100 m 2 of total stream area.