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Journal ArticleDOI

Effects of low environmental pH on blood pH and sodium balance of brook trout

01 May 1970-Journal of Experimental Zoology (Wiley Subscription Services, Inc., A Wiley Company)-Vol. 174, Iss: 1, pp 65-71
TL;DR: The inability of brook trout to live in waters of pH less than about five, seems to be related to a drop in blood pH caused by the high hydrogen ion concentration of the medium.
Abstract: Brook trout (Salvelinus fontinales) exposed to a low environmental pH (3.0-3.3) showed a drop in mean blood pH from 7.39 to 6.97. Trout at an environmental pH of 3.5 lost 50% of their total body sodium. Control sodium influx (72.5 micromols/100 g hours) decreased to zero between pH 3.0 and 4.9 as Na efflux increased markedly over control levels. There was no significant difference in body Na content of wild trout from three streams ranging in pH from 6.05 to 7.10. Trout survived 13.1 to 14.7 hours in a 150 mm Na solution of pH 3.5 as compared to 2.5 to 4.9 hours at 100 micrometer Na and the same pH. The inability of brook trout to live in waters of pH less than about five, seems to be related to a drop in blood pH caused by the high hydrogen ion concentration of the medium. The loss of body Na appears to be of secondary importance as a cause of death.
Citations
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Journal ArticleDOI
TL;DR: Preipitation in Europe and eastern North America has become acidic, a result of increases in sulfuric and nitric acid aerosols produced by fossil-fuel combustion, metal smelting, and industrial processes.
Abstract: Precipitation in Europe and eastern North America has become acidic, a result of increases in sulfuric and nitric acid aerosols produced by fossil-fuel combustion, metal smelting, and industrial processes. The increased use of tall smoke stacks and particle removers has increased long-range transport of acidic gases. Some metals and organic compounds also are transported atmospherically and deposited in acidic precipitation. In regions where acid-neutralizing capacity of soils and water is low, the pH of lakes and streams has decreased and concentrations of metals have increased. Aquatic organisms have been affected in all trophic levels (decomposers, primary producers, primary and secondary consumers); abundance, production, and growth have been reduced and sensitive species have been lost. Fish have suffered acute mortality, reduced growth, skeletal deformities, and especially reproductive failure. Valuable commercial and recreational fisheries have been lost in certain areas and such losses wi...

480 citations

Journal ArticleDOI
TL;DR: The epithelial transport steps which are affected in the fish gill model resemble those described in the human gut and kidney, sites of action of a variety of environmental toxins.
Abstract: The gill epithelium is the site of gas exchange, ionic regulation, acid-base balance, and nitrogenous waste excretion by fishes. The last three processes are controlled by passive and active transport of various solutes across the epithelium. Various environmental pollutants (e.g., heavy metals, acid rain, and organic xenobiotics) have been found to affect the morphology of the gill epithelium. Associated with these morphological pathologies, one finds alterations in blood ionic levels, as well as gill Na,K-activated ATPase activity and ionic fluxes. Such physiological disturbances may underly the toxicities of these pollutants. In addition, the epithelial transport steps which are affected in the fish gill model resemble those described in the human gut and kidney, sites of action of a variety of environmental toxins.

361 citations

Journal ArticleDOI
TL;DR: It is suggested that the presented sodium turnover model is used in conjunction with the Biotic Ligand Model for risk management decisions, noting that sodium turnover rate is the key predictor for variation in acute copper and silver toxicity amongst groups of freshwater animals.
Abstract: The mechanisms of acute copper and silver toxicity in freshwater organisms appear similar. Both result in inhibition of branchial sodium (and chloride) uptake initiating a cascade of effects leading to mortality. The inhibition of the branchial Na/K-ATPase in the basolateral membrane is generally accepted as the key component responsible for the reduced sodium uptake. We propose that branchial carbonic anhydrase and the apical sodium channel may also be important targets for both copper and silver exposure. Several attempts have been made to predict metal sensitivity. A prominent example is the geochemical–biotic ligand model. The geochemical–biotic ligand modeling approach has been successful in explaining variations in tolerance to metal exposure for specific groups of animals exposed at different water chemistries. This approach, however, cannot explain the large observed variation in tolerance to these metals amongst different groups of freshwater animals (i.e. Daphnia vs. fish). Based on the detailed knowledge of physiological responses to acute metal exposure, the present review offers an explanation for the observed variation in tolerance. Smaller animals are more sensitive than large animals because they exhibit higher sodium turnover rates. The same relative inhibition of sodium uptake results in faster depletion of internal sodium in animals with higher sodium turnover. We present a way to improve predictions of acute metal sensitivity, noting that sodium turnover rate is the key predictor for variation in acute copper and silver toxicity amongst groups of freshwater animals. We suggest that the presented sodium turnover model is used in conjunction with the Biotic Ligand Model for risk management decisions.

330 citations

Journal ArticleDOI
05 Feb 1976-Nature
TL;DR: The decline in freshwater fish populations in parts of southern Norway is associated with increasing acidity in rivers and lakes, and the salmon has been eliminated from many rivers, and hundreds of lakes have lost their trout populations.
Abstract: THE decline in freshwater fish populations in parts of southern Norway is associated with increasing acidity in rivers and lakes1. The salmon has been eliminated from many rivers, and hundreds of lakes have lost their trout populations. The chief cause of increased acidity is acid precipitation which is the product of the emission, oxidation and long-distance transport of air pollutants, particularly sulphur dioxide2,3. Similar observations of acid rain and the disappearance of freshwater fish populations have been made in the United States, Canada and Sweden4–6.

309 citations

Journal ArticleDOI
01 Aug 1980-Ecology
TL;DR: In this paper, dilute concentrations of sulfuric acid were added to Norris Brook, a stream in the Hubbard Brook Experimental Forest, West Thornton, New Hampshire, USA, from April to September 1977.
Abstract: Incident precipitation in the northeastern United States averages about pH 4 as a result of increased pollution from sulfuric and nitric acids. To determine the effect of this increased acidity on the ecology of aquatic ecosystems, dilute concentrations of sulfuric acid were added to Norris Brook, a stream in the Hubbard Brook Experimental Forest, West Thornton, New Hampshire, USA. The stream was maintained at pH 4 from April to September 1977. With increased acidity stream water concentrations of Al, Ca, Mg, K, and probably Mn, Fe, and Cd were elevated; no change in dissolved organic carbon (DOC), Na, NO,, NH4, Ni, Pb, Cu, or Zn occurred at the lower pH. Emergence of adult mayflies (Ephemeroptera), some stoneflies (Plecoptera), and some true flies (Diptera) decreased at the lower pH. Larger numbers of immature aquatic inver- tebrates in the collector, scraper, and predator functional groups were found in drift samples from the experimental area during the 1st wk after acid addition. After the 1st wk of increased acidity total numbers of organisms drifting in the experimental area were similar to values obtained in the reference area. Emergence of adult collectors and invertebrate density in the benthos decreased in the treatment area. Periphyton biomass increased at the low pH, but hyphomycete fungal densities decreased. A basidiomycete fungus increased in the experimental area relative to the reference section. Brook trout showed no morphological signs of stress at the low pH. Stream acidification decreased species di- versity, increased representation of community dominants. and decreased the complexity of the food web.

295 citations

References
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Book
01 Jan 1950

2,348 citations

Journal ArticleDOI
TL;DR: The permeability to water, as measured by tritiated water, is highest in fresh water and lowest in 200% sea water, which is consistent with the drinking rates determined in sea water and 200%Sea water.
Abstract: 1. The total body sodium increases from 45.9 µM/g. fish in fresh water to 59.9 µM/g. fish in 200 % sea water. 2. The rate of exchange of sodium increases from 2 µM/g./hr. in fresh water to 60 µM/g./hr. in 100% sea water. 3. The rate of drinking increases from 0.26%/hr. fresh water to 1.6%/hr. in 400% sea water. Even in 200% sea water drinking accounts for only a quarter of the total sodium influx. 4. The permeability to water, as measured by tritiated water, is highest in fresh water and lowest in 200% sea water. The permeabilities to water measured in this way are consistent with the drinking rates determined in sea water and 200% sea water.

155 citations

Journal ArticleDOI
TL;DR: The relationship between active uptake and external concentrations at low concentrations resembles that found in fresh-water crustaceans.
Abstract: Measurements have been made of the rates of influx and efflux of sodium ions in sea water, 40% sea water and fresh water in the killifish, Fundulus heteroclitus. Measurements have also been made of the rates of efflux of chloride and bromide ions in the same media. The rate of drinking has been measured using inulinlabeled sea water. In sea water the sodium influx averages 20 mM Na/kg./hr., of which more than half enters by diffusion, the rest by drinking. In fresh water the rate of influx is about 0.6 mM Na/kg./hr., practically all of which takes place by active transport. Adaptation to fresh water is accompanied by a great reduction in permeability to sodium and chloride ions. This fall in permeability takes place within a few minutes of transfer to fresh water but the increase of permeability on return to sea water takes many hours. The relationship between active uptake and external concentrations at low concentrations resembles that found in fresh-water crustaceans.

126 citations