Behavior of Atlantic salmon (Salmo salar) During Suspended Migration in an Estuary, Sheet Harbour, Nova Scotia, Observed Visually and By Ultrasonic Tracking

1982 ◽  
Vol 39 (2) ◽  
pp. 248-256 ◽  
Author(s):  
Vivien M. Brawn
Keyword(s):  
Nova Scotia ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Small Area ◽  
Migration Behavior ◽  
Ground Speed ◽  
Atlantic Salmon Salmo Salar ◽  
East River ◽  
Constant Distance ◽  
Ultrasonic Tracking

The movements of adult Atlantic salmon (Salmo salar) were followed in an estuary from August to November 1978 and in July and August 1979 by ultrasonic tracking. During these periods, the proportion of time spent by salmon in apparent random movement inside a small area steadily increased, reaching 97 or 98% in September and October, and then declined. This behavior was observed visually in schools of 17 to 75 salmon which showed no preference for sun or shade, were not easily disturbed, kept a constant distance from the surface associated with the halocline, and were in currents too low to measure. As the frequency of this behavior increased, average ground speed of moving fish decreased. Suspended migrations of up to [Formula: see text] mo were recorded. Salmon planted as smolts in East River and returning as adults remained almost exclusively in the East River arm of the Y-shaped estuary. Salmon favored areas having water deeper than 3 m, but showed no preference for areas deeper than 5 m inside the 3-m contour. Moving fish showed a tendency to move upstream on a rising tide and downstream on a falling tide, but these movements could be reversed by high turbine flows at the mouth of East River. A means of removing ultrasonic tags from live salmon without injury was developed.Key words: Atlantic salmon, estuary, migration, behavior, ultrasonic tracking

An Application of Louver Deflectors for Guiding Atlantic Salmon (Salmo salar) Smolts From Power Turbines

1972 ◽  
Vol 29 (10) ◽  
pp. 1397-1404 ◽  
Author(s):  
L. J. A. Ducharme
Keyword(s):  
Nova Scotia ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Velocity Ratio ◽  
Atlantic Salmon Salmo Salar ◽  
East River ◽  
Approach Velocity ◽  
Flow Turbulence ◽  
Guiding System ◽  
Reduced Flow

Louver deflectors for guiding Atlantic salmon (Salmo salar) away from destructive power turbines were installed in a canal leading to the powerhouse at East River, Sheet Harbour, Nova Scotia, in 1966. Guiding efficiency studies, using hatchery-reared smolts, showed that a minimum approach:bypass velocity ratio of 1.0:1.5 was a prerequisite to high guiding efficiency. From 1967 to 1971, average guiding efficiency was increased from 57% to 80% through modifications which increased velocity and reduced flow turbulence in the bypass. A significant correlation existed between approach velocity and guiding efficiency within the range tested after bypass hydraulics had been modified. Tests conducted with varying louver bar spacing ranging from 5.1 to 30.5 cm (2–12 inches) showed that the wider spacings did not impair guiding efficiency.Vertical distribution of smolt migrants in the power canal indicated that over 80% of the fish remained above depth 1.3 m. This was borne out by the fact that the bypass was effective when operating to a depth of only 0.91 m. An appraisal of the practicality of the louver guiding system is presented.

scholarly journals A Mi’kmaw Perspective on Advancing Salmon Governance in Nova Scotia, Canada: Setting the Stage for Collaborative Co-Existence

2016 ◽  
Vol 7 (3) ◽  
Author(s):  
Shelley K Denny ◽  
Lucia M Fanning
Keyword(s):  
Nova Scotia ◽  
Cultural Identity ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Fisheries Governance ◽  
Multiple Realities ◽  
Atlantic Salmon Salmo Salar ◽  
Governance Regime ◽  
Conservation And Management ◽  
Canadian Department

Issues related to fisheries governance are a source of debate and tension between the Indigenous Mi’kmaq people of Nova Scotia and the Canadian Department of Fisheries and Oceans (DFO) in matters concerning Atlantic salmon, Salmo salar. Within the context of the existing governance regime, this analysis compares the concept of salmon conservation and management from a Mi’kmaq perspective and proposes a collaborative co-existence approach for effective salmon governance in Nova Scotia. This approach begins by using co-management as a process, Two-Eyed Seeing as the design, and treaties as the model to achieve shared objectives of maintaining and improving abundances of salmon populations, in spite of differing mechanisms for addressing the interwoven complexities of multiple realities, conservation, and cultural identity.

The distribution of dissolved aluminum in Atlantic salmon (Salmo salar) rivers of Atlantic Canada and its potential effect on aquatic populations

2012 ◽  
Vol 69 (7) ◽  
pp. 1174-1183 ◽  
Author(s):  
Ian F. Dennis ◽  
Thomas A. Clair
Keyword(s):  
Nova Scotia ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Atlantic Coast ◽  
Data Interpretation ◽  
Potential Effect ◽  
Atlantic Canada ◽  
Aquatic Life ◽  
Atlantic Salmon Salmo Salar ◽  
Advisory Commission

Studies from the 1980s concluded that aluminum (Al) was not a significant contributor to Atlantic salmon ( Salmo salar ) toxicity in Nova Scotia, located on Canada’s Atlantic coast, because of the presence of dissolved organic matter that rendered ionic Al (Ali) biologically inaccessible. Since this earlier work, new interpretations of Ali effects, as well as improved techniques for its measurement, have been developed. However, no new data interpretation has been done to see if the conclusions reached in earlier work for Atlantic Canada were still valid. We sampled 97 salmon rivers from the provinces of New Brunswick (NB), Nova Scotia (NS), and the island of Newfoundland (NF) to determine total and Ali concentrations to see if results exceeded newer toxicity standards established by the European Inland Fisheries Advisory Commission. We found that southwestern NS, the region with the greatest loss of salmon populations, has seven rivers where autumn Ali values exceed values identified as toxic to aquatic life. A further three rivers exceed guidelines in NF. Our work shows that the sources of toxicity for salmon and other aquatic species in acidified environments are more complex than previously thought.

scholarly journals Migration of Postsmolt Atlantic Salmon, Salmo salar, Off Northeastern Newfoundland, As Inferred by Tag Recoveries in a Seabird Colony

1988 ◽  
Vol 45 (3) ◽  
pp. 568-571 ◽  
Author(s):  
W. A. Montevecchi ◽  
D. K. Cairns ◽  
V. L. Birt
Keyword(s):  
Nova Scotia ◽  
Atlantic Salmon ◽  
New England ◽  
Salmo Salar ◽  
Atlantic Coast ◽  
Food Samples ◽  
Seabird Species ◽  
Atlantic Salmon Salmo Salar ◽  
Penobscot River ◽  
Migratory Pattern

Northern gannets, Sula bassanus, and possibly other seabird species nesting on Funk Island off northeastern Newfoundland preyed on postsmolt Atlantic salmon, Salmo salar. Salmon comprised less than 1% of 2928 regurgitated food samples collected from gannets at the colony. Ten smolt tags were recovered in and near the gannetry during August or September in 1984 through 1986. The tags were from smolts released 3–4 mo earlier in the Penobscot River (Maine) (n = 7) and one each from the Saint John River (New Brunswick) and the Lower Clyde and LaHave rivers (Nova Scotia). These recoveries provide evidence that postsmolt Atlantic salmon from rivers in New England, the Bay of Fundy, and the Atlantic coast of Nova Scotia migrate off eastern Newfoundland This migratory pattern contrasts with that of postsmolts from the Gulf of St. Lawrence, which tend to move northwards along Newfoundland's west coast and through the Strait of Belle Isle.

Production of Juvenile Atlantic Salmon (Salmo salar) in Two Acidic Rivers of Nova Scotia

1989 ◽  
Vol 46 (11) ◽  
pp. 2003-2018 ◽  
Author(s):  
Gilles L. Lacroix
Keyword(s):  
Nova Scotia ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Maximum Growth ◽  
Potential Yield ◽  
Atlantic Salmon Salmo Salar ◽  
The North ◽  
Juvenile Atlantic Salmon ◽  
Salmon Population ◽  
Acidic River

Densities, growth, and production of juvenile Atlantic salmon (Salmo salar) were estimated at sites in two acidic rivers of different pH, the Westfield and North rivers, in Nova Scotia, Canada, from 1982 to 1984. Annual production was significantly lower in the more acidic Westfield River (< 0.4 g∙m−2∙yr−1 at pH 4.7–5.4) than in the North River (1.4 g∙m−2∙yr−1 at pH 5.6–6.3). Low production rates in the more acidic river were attributable to the lower densities and poorer survival of juveniles at the lower pH levels. Low densities of parr in the more acidic river were a function of the high initial mortality of postemergent fry, and the mortality of parr during periods of pH minima such as over winter. Marking and recapture information and trapping at a weir for counting migrating fishes indicated that there was little emigration of parr other than in the spring when some movements occurred preceding and during smoltification. Average potential yield of 2-yr smolts was 0.8 smolt/100 m2 in the Westfield River and in the range of 2.7–6.6 smolts/100 m2 at higher pH levels in the North River. Growth was not limiting to production at the lower pH levels. After the first winter, 1-yr-old parr were much larger at the lower pH than they were at less acidic pH levels, the faster growth possibly resulting from the lower density of parr at the lowest pH. A temperature-related biphasic growth of 1-yr-old parr with periods of maximum growth in spring and autumn was recorded. Reduced production, a result of deleterious effects of low pH on survival and density in the Westfield River was probably sufficient to prevent the continued maintenance of a naturally produced salmon population in that river, whereas production at higher pH levels in the North River was comparable to that in near-neutral waters of other areas.

Role of Olfaction in the Behavioral and Neuronal Responses of Atlantic Salmon, Salmo salar, to Hydrographic Stratification

1985 ◽  
Vol 42 (10) ◽  
pp. 1658-1667 ◽  
Author(s):  
Kjell B. Døving ◽  
Håkan Westerberg ◽  
Peter B. Johnsen
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Water Samples ◽  
Olfactory Nerve ◽  
Control Fish ◽  
Fine Scale ◽  
Vertical Movements ◽  
Atlantic Salmon Salmo Salar ◽  
Hydrographic Features ◽  
Ultrasonic Tracking

The behavior of sham-operated and anosmic Atlantic salmon, Salmo salar, was studied in a fjord system with close reference to the fine-scale hydrographic features. Control fish made small-amplitude vertical movements, with sudden large-amplitude excursions. The anosmic fish made large continuous searches up and down in the water column, descended below the sill depth of the fjord, and followed the bottom contours. None of these three behaviors was seen in the control fish. The trauma caused by the surgical incision did not prevent the fish from active swimming, and a fish with unilateral sectioning of the olfactory nerve returned to the river of release. Activity of single olfactory bulb neurons was recorded during stimulation of salmon olfactory epithelium with water samples taken from different depths of the fjord. These water samples had been taken from regions that showed layering and to which migrating salmon demonstrated behavioral preferences in ultrasonic tracking experiments. Ninety percent of responding neurons showed differencial responses to the water samples, indicating the capacity of the olfactory system to discriminate among stratified water layers found in the ocean. We conclude that olfactory discrimination of fine-scale hydrographic features may provide a necessary reference system for successful orientation in nearshore regions by salmon.

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