Decreased Survival and Calcium Uptake by the Crayfish Orconectes virilis in Low pH

1980 ◽  
Vol 37 (3) ◽  
pp. 364-372 ◽  
Author(s):  
D. F. Malley
Keyword(s):  
Acid Rain ◽  
Lake Water ◽  
Calcium Uptake ◽  
Physiological Responses ◽  
Low Ph ◽  
Lake Acidification ◽  
Orconectes Virilis ◽  
Molt Cycle ◽  
Experimental Lakes Area ◽  
Acidification Of Lake

As part of a study of the effects of the experimental whole-lake acidification of Lake 223 in the Experimental Lakes Area on the population of the crayfish Orconectes virilis physiological responses of adults from this population to low pH were examined in the laboratory. Crayfish survived pH 4.0 for 10 d when they were not moulting but suffered mortality when they were in postmolt stages. Postmolt crayfish held at pH 5.0 for 10 d survived but showed slower progression of molt cycle stages and of calcification of the exoskeleton than individuals held at pH 6.0 or in lake water at about pH 6.7. Uptake of Ca++ by postmolt crayfish measured by the use of 45Ca as a tracer was inhibited by pH below 5.75 and ceased altogether below pH 4.0 when these levels of acidity were applied acutely.Key words: Orconectes virilis, crayfish, molt cycle, mortality, pH, calcification, postmolt calcium uptake, acid rain, lake acidification

Reproductive Impairment of the Crayfish Orconectes virilis in Response to Acidification of Lake 223

1987 ◽  
Vol 44 (S1) ◽  
pp. s97-s106 ◽  
Author(s):  
Robert L. France
Keyword(s):  
Egg Production ◽  
Lake Acidification ◽  
Orconectes Virilis ◽  
Experimental Lakes Area ◽  
Rate Of Development ◽  
Northwestern Ontario ◽  
Reproductive Impairment ◽  
Cement Compound ◽  
Acidification Of Lake ◽  
Egg Capsule

Reproductive characteristics of crayfish (Orconectes virilis) were examined during 1979–81 in four small Canadian Shield basins in the Experimental Lakes Area, northwestern Ontario. One of these lakes, Lake 223 (L223), has been experimentally acidified since 1976. Egg resorption, fertilization, and rate of development were not seriously affected by lake acidification to pH 5.1. Incomplete hardening of the glair–cement compound forming the egg capsule membrane and stalk resulted in a loss of eggs from the pleopods, causing the L223 population to suffer decreased reproduction. On an egg production basis, the reproductive impairment (defined as the % decrease in number of viable eggs prior to hatching) in reference populations averaged 3.2 ± 1.8 (95% C.I.) compared to levels of 18.7, 36.2, and 29.4% during 1979–81 in L223 at pH 5.2–5.6. Direct mortality of eggs accounted for little of the reduced natality in the L223 population and did not occur in reference lakes. Loss of crayfish populations exposed to lake acidification will probably result from reproductive failure before lake water becomes acid enough to be directly toxic to mature crayfish.

Population Collapse of the Crayfish Orconectes virilis in Response to Experimental Whole-Lake Acidification

1989 ◽  
Vol 46 (6) ◽  
pp. 910-922 ◽  
Author(s):  
I. J. Davies
Keyword(s):  
Population Size ◽  
Population Decline ◽  
Fish Predation ◽  
Reference Population ◽  
Lake Acidification ◽  
Orconectes Virilis ◽  
Microsporidian Parasite ◽  
Experimental Lakes Area ◽  
Recruitment Failure ◽  
Northwestern Ontario

A population of Orconectes virilis in Lake 223 at the Experimental Lakes Area, northwestern Ontario, was monitored from 1976 to 1982 during an acidification experiment. O. virilis from nearby Lake 240 served as a reference population. Crayfish abundance remained stable as average epilimnion pH was gradually lowered from 6.49 (1976) to 5.93 (1978). In 1979 (pH 5.64) recruitment of young was poor and the overall population size [Formula: see text] fell from 105 800 to 60 300 animals. The decline continued in the complete absence of recruitment during 1980 (pH 5.59, [Formula: see text] and 1981 (pH 5.02, [Formula: see text]. Few crayfish survived until the spring of 1982. None were present from mid-summer 1982 to fall 1983 (average pH 5.09 to 5.13). Hatchling mortality and some egg loss appeared to have been the causes of recruitment failure. Acidification also produced a noticeable softening in the carapace of all intermoult crayfish. Growth, mortality, behaviour, and the basic reproductive functions of juvenile and adult crayfish did not change in response to acidification. Fish predation and the incidence of a microsporidian parasite apparently contributed little to the population decline.

Calcium and Trace Metal Composition of Crayfish (Orconectes virilis) in Relation to Experimental Lake Acidification

1987 ◽  
Vol 44 (S1) ◽  
pp. s107-s113 ◽  
Author(s):  
Robert L. France
Keyword(s):  
Trace Metal ◽  
Dry Weight ◽  
Lake Acidification ◽  
Orconectes Virilis ◽  
Tissue Concentrations ◽  
Experimental Lakes Area ◽  
Background Levels ◽  
Metal Composition ◽  
Mn Content ◽  
Subjective Estimates

Subjective estimates indicate that the carapaces of crayfish from experimentally acidified Lake 223 (pH 5.4–5.6) in the Experimental Lakes Area are becoming less rigid. Decreased carapace rigidity was inversely correlated with carapace dry weight and Ca++ content. Orconectes virilis from L223 have 25–35% less Ca++ in their exoskeletons (mean % dry wt ± SE = 13.90 ± 0.54) than do those from reference lakes (19.82 ± 0.33, 20.34 ± 0.63, and 22.18 ± 0.51). Lake 223 crayfish have accumulated higher tissue concentrations of both Mn (L223 value of 240 μg∙g−1 dry wt compared to a mean ± SE for reference populations of 48 ± 11 μg∙g−1 dry wt) and Hg(L223 value of 0.52 μg∙g−1 dry wt compared to reference mean of 0.26 ± 0.05 μg∙g−1 dry wt). Mn content of carapaces in crayfish from acidified L223 were also elevated threefold over background levels for the ELA region.

Physiological responses of root-less epiphytic plants to acid rain

Ecotoxicology ◽  
2010 ◽  
Vol 20 (2) ◽  
pp. 348-357 ◽  
Author(s):  
Jozef Kováčik ◽  
Bořivoj Klejdus ◽  
Martin Bačkor ◽  
František Štork ◽  
Josef Hedbavny
Keyword(s):  
Acid Rain ◽  
Physiological Responses

Decline of Mysis relicta During the Acidification of Lake 223

1983 ◽  
Vol 40 (11) ◽  
pp. 1905-1911 ◽  
Author(s):  
R. W. Nero ◽  
D. W. Schindler
Keyword(s):  
Confidence Limits ◽  
Experimental Lakes Area ◽  
Mysis Relicta ◽  
Ph Values ◽  
Northwestern Ontario ◽  
Population Comparisons ◽  
Acidification Of Lake ◽  
Ph Range ◽  
Shield Lakes ◽  
Direct Toxicity

The population size of Mysis relicta in Lake 223 of the Experimental Lakes Area, northwestern Ontario, decreased from 6 700 000 ± 1 330 000 (± 95% confidence limits) during August of 1978, to 270 000 ± 75 000 during August of 1979, a 96% decrease. Because Mysis, a cold stenotherm, is restricted to the metalimnion and hypolimnion of lakes during summer, the pH range encountered by the population was 5.51 to 6.32 in 1978 and 5.23 to 6.10 in 1979, even though mean pH values in epilimnion waters for the 2 yr were 5.84 and 5.60. A decrease in pH of its habitat from 6.2 to 5.6 during fall overturn in 1979 caused the elimination of the remaining 4% of the population. Comparisons with four control lakes suggested that the decline and disappearance were not normal occurrences in unstressed lakes. Concentrations of Zn, Al, Mn, Fe, Cd, Cu, Ni, and Hg in Lake 223 water were low, and concentrations in Mysis were less than or equal to those in animals from five control lakes, suggesting that the decline in this species was not due to the toxic effects of metals. All size classes were affected, so that direct toxicity of hydrogen ion may be responsible for this abrupt population collapse. These results suggest that Mysis may be a useful early indicator of acidification damage to Precambrian Shield lakes.

Environmental changes affecting physiological responses and growth of hybrid grouper – The interactive impact of low pH and temperature

2021 ◽  
Vol 271 ◽  
pp. 116375
Author(s):  
Yusnita A Thalib ◽  
Ros Suhaida Razali ◽  
Suhaini Mohamad ◽  
Rabi’atul ‘Adawiyyah Zainuddin ◽  
Sharifah Rahmah ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Physiological Responses ◽  
Low Ph ◽  
Hybrid Grouper

Effects of rainfall acidity and ozone on foliar leaching in red spruce (Picea rubens)

1999 ◽  
Vol 29 (4) ◽  
pp. 487-496 ◽  
Author(s):  
Roger G Sayre ◽  
Timothy J Fahey
Keyword(s):  
Acid Rain ◽  
Base Cation ◽  
Low Ph ◽  
Picea Rubens ◽  
Red Spruce ◽  
Cation Leaching ◽  
Cuticle Formation ◽  
Canopy Leaching ◽  
Post Hoc ◽  
Calcium Pool

The effects of acid rain and ozone on the leaching of chemicals from the canopy of red spruce (Picea rubens Sarg.) saplings was measured over a 4-year treatment period. The saplings were exposed to various levels of ozone and to acid rain (pH 3.1, 4.1, and 5.1) using open-top chambers. No effects of ozone treatments on canopy leaching were observed. Significant effects of rainfall pH on canopy leaching of Ca2+ and Mg2+ were observed, and post-hoc analysis indicated that these effects were associated only with the most acidic treatment (pH 3.1). In the low pH treatment (high NO3- and SO42-) significant canopy retention of both NO3- and SO42- were observed. The observed increase in base cation leaching flux from the red spruce canopy in the low pH treatment was particularly prominent early in the growing season (June) probably reflecting incomplete cuticle formation in the young foliage. Although the annual magnitude of extra Ca2+ leaching from the canopy of red spruce trees in the low pH treatment was small relative to the foliar calcium pool (about 10%), if this leaching preferentially depletes a physiologically important pool, it may influence tree health.

Common loon reproduction and chick feeding on acidified lakes in the Adirondack Park, New York

1988 ◽  
Vol 66 (4) ◽  
pp. 804-810 ◽  
Author(s):  
Karl E. Parker
Keyword(s):  
New York ◽  
Food Resource ◽  
Resource Depletion ◽  
Low Ph ◽  
Lake Acidification ◽  
Common Loon ◽  
Feeding Problems ◽  
Short Term ◽  
Lake Acidity ◽  
Adirondack Lakes

The effects of lake acidification on common loon reproduction were studied on a total of 24 Adirondack lakes from May through August in 1983 and 1984. The lakes ranged in size from 10.5 to 179 ha; pH ranged from 4.65 to 6.77 and alkalinity from −66 to 111 μequiv./L. Although loons nesting on small, low-pH lakes had a high fledging rate, possibly because of reduced disturbance or predation, no significant relationship (P > 0.10) was found between lake acidity status and loon reproductive success. No chick mortality could be attributed to lake acidification, but chicks on low-pH lakes were generally fed prey much smaller or much larger than those normally preferred. A pair nesting on a fishless lake fed aquatic insects to their constantly begging chick, spending two to four times longer feeding the chick compared with loons on lakes with fish. This pair, alternating absences, flew to another lake to feed, and on three occasions returned to the nesting lake carrying a fish. Loons on the low-pH study lakes apparently adapted, at least in the short term, to food resource depletion associated with acidification. Despite this, acidification creates potentially severe feeding problems for chicks by reducing prey diversity and quantity.

Maintenance of Iron Meromixis by Iron Redeposition in a Rapidly Flushed Monimolimnion

1980 ◽  
Vol 37 (8) ◽  
pp. 1303-1313 ◽  
Author(s):  
P. Campbell ◽  
T. Torgersen
Keyword(s):  
Organic Matter ◽  
Residence Time ◽  
Deep Water ◽  
Lake Water ◽  
Redox Reactions ◽  
Water Mass ◽  
Experimental Lakes Area ◽  
Water Renewal ◽  
Renewal Time ◽  
High Concentrations

Water mass ages determined by the 3H–3He method gave a water renewal time of 2.5 ± 1 yr for the monimolimnion of softwater iron meromictic Lake 120. The water renewal time of the monimolimnion is less than, or equal to, the renewal time of the whole lake. The monimolimnion of Lake 120 was, therefore, not found to be a stratum of "perennially stagnant deep water." The rates of supply to, and degradation of, organic matter in the monimolimnion are responsible, in the first place, for the low redox potential necessary to establish the high concentrations of soluble Fe2+ observed (up to 4.2 mmol∙L−1). However, it was found that the major key to maintenance of high monimolimnetic concentrations of Fe, i.e. maintenance of iron meromixis, is recycling of Fe at the chemocline by an [Formula: see text] "Ferrous Wheel." Up to 90% recycling of iron between chemocline and monimolimnion results in an iron residence time of [Formula: see text] for the whole lake (greater than 4 times the whole lake water renewal time).Key words: meromixis, iron recycling, 3H–3He water ages, water renewal times, chemical budgets, sediment funneling, redox reactions, Experimental Lakes Area (ELA).

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