摘要:

Potentiometric pH measurement in low ionic strength stream waters is difficult due to high system variability and low ionic activity. Imprecise measurement may result from equipment response in such waters and solution pH drift caused by gaseous exchange and temperature change. An acceptable method for field pH determination must utilize sensitive equipment and stringent measurement stability criteria to ensure accurate and reliable measurements. Four methods for in situ and streamside pH determination were used to collect data from three low-ionic strength streams. The methods are compared, using analysis of variance and subjective evaluation.

ISSN:1040-2381    

DOI:10.1080/07438148709354795

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The LAMP research is designed to evaluate chemical and biological response to liming in three different drainage lakes in the Adirondacks. The three lakes vary in size, residence time, chemical composition, and biological community composition, encompassing the range of lakes considered in an operational lake liming program. This ecological experiment provides data for use in evaluating specific questions about liming effects on lake ecosystems; namely, fish and other biotic responses to liming, the effects of liming on acidic impulses during spring runoff, and questions related to metal availability and to modeling of pH and ANC. This paper provides an overview of LAMP, describes the liming of Cranberry Pond and Woods Lake in May 1985, and introduces more detailed papers in this symposium by Drisooll et al., Gloss et al., and DePinto et al. that describe the chemical and biological effects of liming and the ability to predict reacidification. Overall, these initial results of LAMP support the thesis that liming is beneficial to acidic lake ecosystems.

ISSN:1040-2381    

DOI:10.1080/07438148709354796

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The effects of atmospheric deposition on acid-sensitive watersheds have become increasingly apparent. Lake/watershed systems that cannot completely neutralize strong acid inputs are characterized by low pH values and elevated concentrations of trace metals. Populations of fish and other aquatic biota are endangered by this phenomenon. One approach used to mitigate the effects of surface water acidification is direct application of calcium carbonate (CaCO3). Through the Lake Acidification Mitigation Project (LAMP), we investigated the chemical response of acidic lakes to base treatment. Immediately following base application, there was a marked increase in pH, acid neutralizing capacity (ANC), calcium and dissolved inorganic carbon (DIC) associated with the dissolution of calcium carbonate in the treated lakes. The large increase in pH was attributed to the low dissolved inorganic carbon concentrations in the water column prior to liming and limited pH buffering capacity. During the four week period following base application the intrusion of atmospheric carbon dioxide facilitated additional dissolution of the remaining suspended calcium carbonate. This dissolution was accompanied by a gradual decrease in pH (to below 8) and increases in acid neutralizing capacity, dissolved calcium and dissolved inorganic carbon concentrations within the lakes. Concentrations of trace metals in the upper waters decreased about one order of magnitude due to reduced solubility at circumneutral pH values. The rate of reacidification was directly related to the hydrologic input to the lake. Elevated discharge during the fall coinciding with a completely mixed water column greatly facilitated reacidification. Although discharge was very high during spring snowmelt, ice cover and inverse thermal stratification restricted intrusion of acidic meltwater to the ice-water interface. The rapid rate of reacidification was largely attributed to the shallow depth and short hydraulic retention of these lakes.

ISSN:1040-2381    

DOI:10.1080/07438148709354797

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Some lakes with an historical record of fish populations have undergone acidification and fish no longer exist in these systems. Toxicity data suggest that the inability of fish to survive in these acidic environments is due to increased concentrations of hydrogen ion (H+) and aluminum (Al+++) in the water column. To reestablish fish populations in lakes of this kind it is necessary to (1) determine that fish are no longer present, (2) demonstrate that fish either cannot or have limited potential to survive in the systems, and (3) change the water quality, and demonstrate increased survival of fish under differing chemical conditions. We examined two acidic lakes (Woods Lake, pH ~5.0 and Cranberry Pond, pH ~4.8) for the first two conditions by conducting fisheries surveys and in situ bioassays using fingerling (age 0) brook trout (Salvelinus fontinalis). Woods Lake was also stocked with brook trout in the fall of 1984 and overwinter survival of two age classes determined. Emigration from the lake accounted for a relatively small percentage of the approximately 90 percent mortality in these stocked fish over winter. Neither acclimation procedures or experimental selection of brook trout for acid tolerance improved survival. Prior to, during, and after calcium carbonate addition to the lakes in the early summer of 1985 an extensive series of in situ bioassays was conducted that showed significantly improved survival of both age 0 and 1 brook trout after liming. Interactive effects of temperature, pH, and aluminum levels were evident during these experiments. No detrimental effects of liming on fish survival were observed.

ISSN:1040-2381    

DOI:10.1080/07438148709354798

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

A mathematical model (ALaRM) for predicting the reacidification profile of calcium carbonate treated lakes has been calibrated and confirmed using data from two Lake Acidification Mitigation Project (LAMP) lakes. This manuscript focused on the use of ALaRM to evaluate the relative impact of bottom sediment processes on the reacidification rate of the LAMP lakes. Prior to liming the lakes exhibited annual average sediment-to-water ANC fluxes of 194 and 240 meq/m2-yr for Woods Lake and Cranberry Pond, respectively. Following liming there was a period of net water-to-sediment ANC flux due to a reversal of the gradients of ANC-determining chemical species, indicating a buffering effect of bottom sediments on water column acid-base chemistry. A sensitivity analysis indicated that calcite treatment of sediments as well as the water column could mitigate the sediment reacidification-accelerating effect.

ISSN:1040-2381    

DOI:10.1080/07438148709354799

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The ice application of agricultural limestone (220 mesh, 5 tons/ha) to White Deer Lake in February 1985 followed four seasons of baseline data collection. Immediate chemical changes in the lake occurred for total alkalinity, specific conductance, calcium, Secchi depth, magnesium, and silica as the limestone continued to dissolve for nearly seven months. In October 1985 White Deer Lake began to exhibit clear patterns of re-acidification such as declining total alkalinity, and changes in specific conductance, calcium, and magnesium following the dilution of the treated waters after Hurricane Gloria. Reacidification continued through the summer of 1986. Monitoring continues at White Deer Lake.

ISSN:1040-2381    

DOI:10.1080/07438148709354800

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Some Massachusetts lakes are experimentally limed to raise water column pH and alkalinity to mitigate the effects of acidification and to aid in fisheries management. This study evaluated the ecological effects of liming by comparing and contrasting several water chemistry and ecological variables in two softwater ponds. Physical, chemical, and biological parameters have been monitored in Great Pond, Truro, Massachusetts, before and following the addition of lime in March, 1985. Ryder Pond, Truro, Massachusetts, a nearby similar kettle pond that has never been limed, was concurrently monitored as a reference. Results with implications for water resources and fisheries management strategies are presented.Micropterusdolomieui(smallmouth bass) recruitment was successful following liming. Zooplankton and chironomids, both fish prey, declined after liming, however. Elevated calcium concentrations persisting after pH has declined may permit longer intervals between liming events.

ISSN:1040-2381    

DOI:10.1080/07438148709354801

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The response of the phytoplankton and zooplankton communities of three acidic Adirondack lakes to chemical neutralization is reported. The addition of base to the three lakes effectively neutralized acid conditions, raising pH from ~4.50 to 6.02 to 7.3. Concentrations of major ions were generally unaffected by neutralization treatment but aluminum concentrations were reduced. The phytoplankton and planktonic rotifer communities were initially decimated by the water column treatments but recovered within the first growing season following treatment. Species richness and standing crops of phytoplankton and rotifers approached or exceeded pre-treatment values within a year of neutralization. The crustacean community was generally slower to respond to base additions. Phytoplankton, rotifer, and crustacean community composition was changed in all lakes following treatment.

ISSN:1040-2381    

DOI:10.1080/07438148709354802

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Three techniques of stream liming were analyzed with respect to dissolution efficiency, ability to treat fluctuations in flow and effects on selected water quality parameters: a slurried-powder mechanical doser, a rotary drum system, and a limestone aggregate stream barrier. All achieved similar minimum levels of alkalinity and pH. The doses of calcium carbonate produced by both mechanical treatment methods were relatively unaffected by flow while the limestone barrier lost effectiveness at higher flows. Analysis of changes in concentrations of metals (particularly aluminum) indicated a complex interaction between base material addition and metals. The base material added by the slurried-powder doser appears to have contributed to an observed increase in total aluminum concentrations downstream of the doser. The limestone barrier appears to have acted as a sink for aluminum during low flows, subsequently releasing the metal during high flows. The treatment methods reviewed all appear capable of achieving water quality targets under specific conditions. Care must be taken, however, in selection of materials in order to produce desirable reductions in potentially toxic constituents.

ISSN:1040-2381    

DOI:10.1080/07438148709354803

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The National Surface Water Survey represents a unique design for determining, with known confidence, the numbers and percentages of lakes and streams in large regions of the United States that have chemical characteristics that can be interpreted in light of present conditions, past damage, and future potential impacts of acid deposition. The Survey also provides a framework for interpreting future, site-specific intensive studies in a regional context. This paper describes the basis for this design, as well as some strengths and weaknesses of regional, as opposed to the more traditional single-system, approaches to lake and stream management.

ISSN:1040-2381    

DOI:10.1080/07438148709354804

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor