Effects of episodic acidification on Atlantic salmon (Salmo salar) smolts

2003 ◽  
Vol 60 (2) ◽  
pp. 214-221 ◽  
Author(s):  
J A Magee ◽  
M Obedzinski ◽  
S D McCormick ◽  
J F Kocik
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Citrate Synthase ◽  
Recovery Period ◽  
Plasma Potassium ◽  
Plasma Sodium ◽  
Episodic Acidification ◽  
Atlantic Salmon Salmo Salar ◽  
Water Ph ◽  
Acidic Conditions

The effect of episodic acidification on Atlantic salmon (Salmo salar) smolt physiology and survival in fresh water (FW) and seawater (SW) was investigated. Smolts were held in either ambient (control, pH 6.0–6.6), acidified (chronic, pH 4.4–6.1), or episodically acidified (episodic, pH reduction from control levels to pH ~5.2 for 48 h once weekly) river water for 31 days and then transferred to 34‰ SW. Smolts fed little while in acidified conditions and chronic smolts did not grow in length or weight. In FW, chronic smolts experienced increases in hematocrit and plasma potassium and reductions in plasma sodium and chloride. Upon transfer to SW, chronic and episodic smolts experienced reductions in hematocrit, increases in plasma sodium, chloride, and potassium levels, and suffered mortalities. Gill Na+,K+-ATPase and citrate synthase activities were reduced by exposure to acid. For most parameters, the effect of episodic acid exposure was less than that of chronic acidification. Exposure to acidic conditions, even when short in duration and followed by a 30-h recovery period in suitable water (pH 6.5), led to a 35% mortality of smolts upon transfer to SW. This study highlights the importance of measuring and assessing sublethal stresses in FW and their ultimate effects in marine ecosystems.

Effects of Diet or Liming on Steroid Hormone Metabolism and Reproduction in Atlantic Salmon (Salmo salar) Held in an Acidic River

1990 ◽  
Vol 47 (12) ◽  
pp. 2422-2430 ◽  
Author(s):  
G. B. Sangalang ◽  
H. C. Freeman ◽  
J. F. Uthe ◽  
L. S. Sperry
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Reproductive Performance ◽  
Steroid Hormone ◽  
Control Fish ◽  
Dietary Salt ◽  
Hormone Metabolism ◽  
Atlantic Salmon Salmo Salar ◽  
Water Ph ◽  
Acidic River

Attempts to avert the impacts of an acidic river environment on Atlantic salmon (Salmo salar) were carried out in 1985 and 1986. Salmon were held in the Westfield River (pH 4.7–5.2) and the nearby Medway River (pH 5.3–5.6) during their sexual maturation. A diet containing 3% NaCl was fed to the Westfield salmon in 1985. Marble chips were used to elevate the pH of Westfield River water in 1986. Fish fed the salt diet had higher peak levels of plasma sex hormones, higher fecundity, greater incidence of spawners, lower egg mortality, and less weight loss than fish fed a commercial trout diet. The reproductive performance of fish held in limed water (pH 5.1–5.9) almost attained the level observed in the Medway (control) fish. Limestone treatment stimulated early peaking of blood androgen levels, testosterone, and 11-ketotestosterone in Westfield males, and 17α, 20β-dihydroxy-4-pregnen-3-one, a follicular mediator of gonadotropin, in a few Westfield females. The head kidneys produced more cortisol and corticosterone in all Westfield fish in both years compared to Medway fish. The results suggest that neither dietary salt nor liming completely prevented the decline of reproductive performance and the alteration of steroid hormone metabolism in salmon.

Evidence for episodic acidification effects on migrating Atlantic salmon Salmo salar smolts

2015 ◽  
Vol 87 (5) ◽  
pp. 1129-1146 ◽  
Author(s):  
J. T. Kelly ◽  
D. T. Lerner ◽  
M. F. O'Dea ◽  
A. M. Regish ◽  
M. Y. Monette ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Episodic Acidification ◽  
Atlantic Salmon Salmo Salar

Effects of acid rainfall on juvenile Atlantic salmon (Salmo salar) antipredator behaviour: loss of chemical alarm function and potential survival consequences during predation

2009 ◽  
Vol 60 (12) ◽  
pp. 1223 ◽  
Author(s):  
Antoine O. H. C. Leduc ◽  
Ellie Roh ◽  
Grant E. Brown
Keyword(s):  
Rainbow Trout ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Antipredator Behaviour ◽  
Chemical Information ◽  
Alarm Cues ◽  
Episodic Acidification ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon ◽  
Chemical Alarm Cues

Many organisms rely on chemosensory cues to mediate predation risks. Recent studies have demonstrated impaired chemosensory detection ability under weak acidification. Because rainfall may lead to episodic acidification of surface water, we assessed the effects of acid rain on chemosensory alarm functions. Under natural conditions, we quantified alarm behaviour of juvenile Atlantic salmon (Salmo salar) exposed to conspecific chemical alarm cues before and following rainfall. Before rainfall, salmon were capable of an alarm response in the study streams. After rainfall, salmon from Devil’s Brook did not respond to the alarm cues whereas the detection of salmon from Catamaran Brook (a comparable stream having higher acid neutralising capacity) was maintained. To relate these findings to predator–prey encounters, we performed a second experiment where we staged encounters between prey (rainbow trout, Oncorhynchus mykiss) and predator (largemouth bass, Micropterus salmoides) exposed to acidified and unacidified rainbow trout chemical alarm cues. Trout exposed to acidified alarm cues survived for a significantly shorter amount of time than trout exposed to unacidified alarm cues, whereas no difference in overall predator behaviour was observed. Our results suggest that episodic acidification in small nursery streams may disrupt the chemical information mediated by the chemical alarm cues that can translate into higher survival costs for prey.

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.

Metabolic enzyme activity during smolting in stream- and hatchery-reared Atlantic salmon (Salmo salar)

2001 ◽  
Vol 58 (8) ◽  
pp. 1585-1593 ◽  
Author(s):  
Jill BK Leonard ◽  
Stephen D McCormick
Keyword(s):  
Enzyme Activity ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
White Muscle ◽  
Citrate Synthase ◽  
Metabolic Enzyme ◽  
Term Survival ◽  
Atlantic Salmon Salmo Salar ◽  
Metabolic Enzyme Activity ◽  
Heart Size

To evaluate the metabolic differences between Atlantic salmon (Salmo salar) parr and smolts and the effect of rearing environment, we examined metabolic enzyme activity in white muscle, liver, and heart in stream- and hatchery-reared juveniles. Spring increases in gill Na+,K+-ATPase (3.5-fold) and cardiosomatic index (37–69%) and decreases in condition factor (~17%) occurred in smolts, but not in parr. White muscle phosphofructokinase (PFK) increased during spring and was 3.6-fold higher in smolts than in parr by late spring. There were seasonal increases in liver citrate synthase (CS) (~42%), liver β-hydroxyacyl-coenzyme A dehydrogenase (HOAD) (~60%), and heart CS (~23%) and decreases in liver lactate dehydrogenase (LDH) (~28%) in parr and smolts. Activity of liver HOAD was greater in stream-reared smolts (~18%) than in parr or hatchery smolts. Heart PFK activity increased during spring in wild-reared parr and smolts, while it decreased in hatchery-reared smolts. White muscle LDH and PFK increased earlier in spring in hatchery- than in stream-reared smolts. Our results suggest that increased heart size and high white muscle PFK occur during smolting and may be adaptive for downstream and ocean migration. Hatchery- and stream-reared Atlantic salmon differ in the timing of metabolic changes during smolting, which may impact their long-term survival.

Response and Recovery of Brain Acetylcholinesterase Activity in Atlantic Salmon (Salmo salar) Exposed to Fenitrothion

1990 ◽  
Vol 47 (9) ◽  
pp. 1652-1654 ◽  
Author(s):  
M. J. Morgan ◽  
L. L. Fancey ◽  
J. W. Kiceniuk
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Recovery Period ◽  
Acetylcholinesterase Activity ◽  
Technical Grade ◽  
Atlantic Salmon Salmo Salar ◽  
Response And Recovery ◽  
Low Levels ◽  
Operational Formulation ◽  
Brain Acetylcholinesterase

Atlantic salmon (Salmo salar) parr were exposed to a number of concentrations of either technical grade fenitrothion or an operational formulation of the pesticide for 7 d or to the operational formulation for two, 24 h periods separated by 7 d. Brain acetylcholinesterase (AChE) activity decreased as concentration, of fenitrothion increased. Recovery period was directly related to amount of depression, with recovery of AChE from exposure to 0.004 μL/L fenitrothion taking less than 1 wk. Samples must be taken soon after spray operations to detect exposure to such low levels of fenitrothion through AChE monitoring.

Effect of Fluoride Complexation on Aluminum Toxicity Towards Juvenile Atlantic Salmon (Salmo salar)

1990 ◽  
Vol 47 (7) ◽  
pp. 1446-1452 ◽  
Author(s):  
Kevin J. Wilkinson ◽  
Peter G. C. Campbell ◽  
Pierre Couture
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Aluminum Toxicity ◽  
Mixed Ligand Complex ◽  
Gill Tissue ◽  
Plasma Sodium ◽  
Ligand Complex ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon ◽  
Fluoride Complexation

In 7-d semistatic bioassays, fluoride complexation attenuated Al toxicity to juvenile Atlantic salmon (Salmo salar; age 1 +) and the accumulation of Al in gill tissue, but not to the extent predicted by the free-ion model of metal toxicity. Bioaccumulation and toxicity persisted even in the presence of an excess of the complexing ligand. An equilibrium model, involving the formation of a mixed ligand complex (F–Al–L-gill) at the gill surface, is proposed to explain this residual toxicity (L-gill = ligand at the gill surface). Exposure to Al, or to a combination of Al and F, led to a decrease in the plasma sodium levels even for sublethal conditions. Aluminum concentrations as low as 2 μM adversely affected the salmon. The similarity of the osmo-regulatory response to the H+-ion, to Al3+, and to Al(F)x suggested that the mechanism of toxicity in the presence of fluoride did not differ markedly from that observed by previous workers for salmonid species exposed to moderately acidic media containing Al but without added fluoride.

Uptake of cadmium by eggs and alevins of atlantic salmon (Salmo salar) as influenced by acidic conditions

1985 ◽  
Vol 34 (1) ◽  
pp. 359-368 ◽  
Author(s):  
R. H. Peterson ◽  
J. L. Metcalfe ◽  
S. Ray
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Atlantic Salmon Salmo Salar ◽  
Acidic Conditions

Smolting Status of Downstream Migrating Atlantic Salmon (Salmo salar) Parr

1990 ◽  
Vol 47 (6) ◽  
pp. 1136-1139 ◽  
Author(s):  
Tim P. Birt ◽  
John M. Green ◽  
William S. Davidson
Keyword(s):  
Moisture Content ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Salinity Tolerance ◽  
Sodium Concentration ◽  
Plasma Sodium ◽  
Atlantic Salmon Salmo Salar ◽  
Plasma Sodium Concentration ◽  
Gradual Development ◽  
Freshwater River

Significant numbers of Atlantic salmon (Salmo salar) parr have been observed to accompany seaward migrating smolts in some rivers. Downstream migrating parr in Freshwater River Newfoundland, have lower salinity tolerance and branchial Na+–K+ ATPase activity than smolts. However, moisture content in downstream migrating parr was similar to that of smolts; both groups had higher mean moisture content than nonmigratory parr. Mean plasma sodium concentration was significantly higher than in smolts, but somewhat lower than in nonmigratory parr. Elevated moisture levels and slightly depressed plasma sodium concentrations are consistent with the view that seaward movement is associated with osmoregulatory imbalance in both parr and smolts. Brackish water found in estuaries appears important for gradual development of salinity tolerance in these migrants.

Impacts of episodic acidification on in-stream survival and physiological impairment of Atlantic salmon (Salmo salar) smolts

2009 ◽  
Vol 66 (3) ◽  
pp. 394-403 ◽  
Author(s):  
Stephen D. McCormick ◽  
Amanda Keyes ◽  
Keith H. Nislow ◽  
Michelle Y. Monette
Keyword(s):  
Atlantic Salmon ◽  
New England ◽  
Salmo Salar ◽  
Ion Homeostasis ◽  
High Water ◽  
Connecticut River ◽  
Episodic Acidification ◽  
Atlantic Salmon Salmo Salar ◽  
Wide Range ◽  
Plasma Chloride

We conducted field studies to determine the levels of acid and aluminum (Al) that affect survival, smolt development, ion homeostasis, and stress in Atlantic salmon ( Salmo salar ) smolts in restoration streams of the Connecticut River in southern Vermont, USA. Fish were held in cages in five streams encompassing a wide range of acid and Al levels for two 6-day intervals during the peak of smolt development in late April and early May. Physiological parameters were unchanged from initial sampling at the hatchery and the high water quality reference site (pH > 7.0, inorganic Al < 12 μg·L–1). Mortality, substantial loss of plasma chloride, and gill Na+/K+-ATPase activity, and elevated gill Al occurred at sites with the lowest pH (5.4–5.6) and highest inorganic Al (50–80 μg·L–1). Moderate loss of plasma chloride, increased plasma cortisol and glucose, and moderately elevated gill Al occurred at less severely impacted sites. Gill Al was a better predictor of integrated physiological impacts than water chemistry alone. The results indicate that Al and low pH under field conditions in some New England streams can cause mortality and impair smolt development in juvenile Atlantic salmon and provide direct evidence that episodic acidification is impacting conservation and recovery of Atlantic salmon in the northeastern USA.

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