Responses of atlantic salmon (Salmo salar) alevins to dissolved organic carbon and dissolved aluminum at low pH

1989 ◽  
Vol 46 (1-4) ◽  
pp. 399-413
Author(s):  
R. H. Peterson ◽  
R. A. Bourbonnière ◽  
G. L. Lacroix ◽  
D. J. Martin-Robichaud ◽  
P. Takats ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Atlantic Salmon ◽  
Dissolved Organic Carbon ◽  
Salmo Salar ◽  
Low Ph ◽  
Atlantic Salmon Salmo Salar ◽  
Dissolved Aluminum

Inhibition of Atlantic Salmon (Salmo salar) Hatching at Low pH

1980 ◽  
Vol 37 (5) ◽  
pp. 770-774 ◽  
Author(s):  
R. H. Peterson ◽  
P. G. Daye ◽  
J. L. Metcalfe
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Low Ph ◽  
Hatching Enzyme ◽  
Atlantic Salmon Salmo Salar ◽  
Salmon Eggs ◽  
Perivitelline Fluid ◽  
Eye Pigmentation ◽  
Ambient Levels

Hatching of Atlantic salmon (Salmo salar) eggs was delayed or prevented if they were exposed to water of lowered pH (4.0–5.5) after eye pigmentation had developed. Hatching subsequently could be induced by returning eggs to normal pH levels (6.6–6.8). Perivitelline pH fell rapidly to near ambient levels when eggs were exposed to low pH. It is suggested that the observed effects on hatching were due to inhibition of the hatching enzyme, chorionase.Key words: Atlantic salmon, eggs, pH, perivitelline fluid, chorionase

Effects of Low Environmental pH on Smolting of Atlantic Salmon (Salmo salar)

1983 ◽  
Vol 40 (8) ◽  
pp. 1203-1211 ◽  
Author(s):  
Richard L. Saunders ◽  
Eugene B. Henderson ◽  
Paul R. Harmon ◽  
C. Edward Johnston ◽  
J. Geoffrey Eales
Keyword(s):  
Atlantic Salmon ◽  
Atpase Activity ◽  
Salmo Salar ◽  
Constant Temperature ◽  
Water Hardness ◽  
Low Ph ◽  
Temperature Plasma ◽  
Atlantic Salmon Salmo Salar ◽  
Temperature Regimes ◽  
And Control

We reared Atlantic salmon (Salmo salar) in soft water (hardness 13 mg/L as CaCO3) at two pH levels, 6.4–6.7 and 4.2–4.7, from February to June, to assess the effect of low pH on survival, growth, and the smolting process under rising (4–8.5 °C) or relatively constant (9.5–10.5 °C) temperature. Survival was lower as a result of low pH (4.2–4.7) under both temperature regimes. Neither group exposed to low pH gained weight whereas both control groups gained weight during the experiment. Parr–smolt transformation, as indicated by salinity tolerance and gill Na+, K+ ATPase activity, was impaired as a result of low pH. The large (17–19 cm) parr used in this study were initially salinity tolerant and those at control pH (6.4–6.7) increased tolerance to 35‰ salinity between March and May; those in low pH became intolerant of high salinity. ATPase levels in salmon reared at low pH were significantly lower than those at normal pH levels under both temperature regimes. ATPase activity was significantly greater in fish reared at pH 6.4–6.7 with rising than with constant temperature. Plasma chloride and sodium levels were low in response to low pH, indicating impaired ionic regulation in freshwater. Plasma calcium levels were higher at low pH in both temperature regimes; higher levels were reached under constant temperature. Moisture content rose less sharply under low than under control pH in both temperature regimes. In the rising temperature regime, lipid levels reached similar, low levels under low and control pH conditions. Thyroid hormone (T3 and T4) levels gave no clear indication of effects of low pH on smolting. Smoltification did not proceed normally in our Atlantic salmon subjected to low pH levels.

Responses of Juvenile Atlantic Salmon (Salmo salar) to Episodic Increases in Acidity of Nova Scotia Rivers

1987 ◽  
Vol 44 (8) ◽  
pp. 1475-1484 ◽  
Author(s):  
Gilles L. Lacroix ◽  
Donald R. Townsend
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Plasma Sodium ◽  
Ph Change ◽  
Atlantic Salmon Salmo Salar ◽  
Cough Response ◽  
Dissolved Aluminum ◽  
Electrolyte Loss ◽  
Decreasing Ph ◽  
Chloride Concentrations

Toxicity of different pH levels to Atlantic salmon (Salmo salar) parr held in floating pens for 54 d was assessed in four acidic streams of Atlantic Canada during the autumnal episode of increasing acidity. All parr died in the two streams where pH levels decreased below pH 4.7. Mortality was related to the rate of pH change and to parr size. Plasma sodium and chloride concentrations decreased by about 50–70 mmol∙L−1in parr of these two streams, and the rate of electrolyte loss was related to the rate and severity of pH change. In the other two streams, pH levels were never lower than pH 4.8 and no fish died. Plasma sodium and chloride concentrations in these parr decreased by 20–30 mmol∙L−1, but only after 30 d of exposure. Increased hematocrit, increased respiratory–cough response, and decreased feeding response, especially for parr in the most acidic streams, were also the result of stress apparently related to decreasing pH levels. Concentrations of labile aluminum were usually less than 10% of total dissolved aluminum and always less than 50 μg∙L−1in the four streams. Accumulation of aluminum in the gills of parr was not a significant factor in the lethal effects observed, which were more likely due to low pH.

Lack of long-term sublethal effects of reduced freshwater pH alone on Atlantic salmon (Salmo salar) smolts subsequently transferred to seawater

2004 ◽  
Vol 61 (4) ◽  
pp. 511-518 ◽  
Author(s):  
Sveinung Fivelstad ◽  
Anne Berit Olsen ◽  
Sigurd Stefansson ◽  
Sigurd Handeland ◽  
Rune Waagbø ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Sublethal Effects ◽  
Growth Parameters ◽  
Gill Tissue ◽  
Low Ph ◽  
Control Group ◽  
Long Term Effects ◽  
Atlantic Salmon Salmo Salar

Atlantic salmon (Salmo salar) smolts (mean start weight 42 g) in soft freshwater were exposed to three pH ranges (two replicates in each group) for 35 days: pH 6.5–6.8 (control group), pH 5.9–6.3 (medium-pH group), and pH 5.4–5.9 (low-pH group). All exposures had citrate added to remove labile, toxic Al from the water. On day 35, all groups were transferred to 34‰ seawater and kept there for 100 days. H+ was the main stressor in the exposures because labile Al was <6 µg·L–1 and the gill Al was lower than 27 µg·g dry weight–1 (highest in the medium group). The exposure environments did not cause any significant changes to gill tissue structures, gill Na+,-K+-ATPase activity, mortality, and growth parameters during the freshwater period. However, haematocrit was significantly increased and mean plasma chloride was significantly reduced (p < 0.05) in the low-pH group compared with the control group. This study indicated that the H+ concentrations in the pH range 5.4–5.9 in water containing no to little gill-reactive Al do not impact salmon growth and physiology during smoltification. However, the reduction in blood haematocrit in the low-pH group 3 months after seawater transfer may imply long-term effects of the treatment.

Effects of Low Environmental pH on the Survival, Growth, and ionic Composition of Postemergent Atlantic Salmon (Salmo salar)

1985 ◽  
Vol 42 (4) ◽  
pp. 768-775 ◽  
Author(s):  
Gilles L. Lacroix ◽  
D. James Gordon ◽  
Dana J. Johnston
Keyword(s):  
Nova Scotia ◽  
Atlantic Salmon ◽  
River Water ◽  
Salmo Salar ◽  
Ionic Composition ◽  
Low Ph ◽  
Atlantic Salmon Salmo Salar ◽  
Flow Through ◽  
Composition Changes

Postemergent Atlantic salmon (Salmo salar) were reared during the early feeding phase in the soft, acidic water of the Westfield River (mean pH 5.0) in Nova Scotia. The fry were held in a flow-through system of tanks in situ and were fed a hatchery diet. Bioassays were also conducted in river water treated with limestone (mean pH 6.1) to provide a control. Cumulative mortality of fry after 30 d in the tanks was 70% at pH 5.0 and only 4% at pH 6.1. Fry in untreated river water were inactive, ingested little food, and lost weight (approximately 25%) during the first 15 d of exposure. Large increases in body [Ca2+] and [Na+] were observed in fry at both pH levels during that time, but the increase in [Ca2+] lagged and that in [Na+] was less in fry at low pH. Deaths occurred 15–30 d after swim-up and dead fry were all severely emaciated, indicating that deaths were probably from starvation. Although there were differences in ionic composition changes in fry held at pH 5.0 compared with control, no major depletion of body ionic reserves occurred relative to initial concentrations. Surviving fry at pH 5.0 developed a tolerance after 25 d and had growth rates, condition factors, and ionic concentrations similar to those of fry in treated water. The mortality of fry during the transition to exogenous feeding, in response to low pH stress in soft water, is probably responsible for reduced recruitment and the decline or loss of salmon stocks in this and other acidic rivers of Nova Scotia.

Embryo Movements of Atlantic Salmon (Salmo salar) as Influenced by pH, Temperature, and State of Development

1983 ◽  
Vol 40 (6) ◽  
pp. 777-782 ◽  
Author(s):  
R. H. Peterson ◽  
D. J. Martin-Robichaud
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Subsequent Development ◽  
Developmental State ◽  
Low Ph ◽  
Temperature Sensitive ◽  
Degree Days ◽  
Pectoral Fin ◽  
Atlantic Salmon Salmo Salar ◽  
Trunk Movements

Two types of embryo movements of Atlantic salmon (Salmo salar), pectoral fin flutter and trunk movements, were measured as a function of incubation temperature, pH, and developmental state. Trunk movements began at 200 degree-days, initially at highest frequency. The frequency decreased throughout subsequent development and then increased slightly just before hatching. Movements were much more stereotyped in the earliest stages of development than just prior to hatching. Frequencies at 200 degree-days were insensitive to temperature and pH. Frequencies just prior to hatching were very temperature sensitive (Q10 of 13) and were decreased at low pH. This decreased frequency may be related to documented effects of temperature and low pH on hatching. Pectoral fin movements were temperature sensitive (Q10 of 2) and pH insensitive. These movements were initiated at 350 degree-days of development and attained maximal frequency at 400 degree-days.

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