Joseph C. Greene

Algal productivity in 49 lake waters as determined by algal assays

Abstract Algal assays were conducted on waters from 49 American lakes to determine whether phosphorus, nitrogen, or some other nutrient was the limiting factor upon algal productivity. A comparison of the known trophic state of 23 American lakes and their bioassay response is presented. Phosphorus limited algal growth in 35 of the 49 lakes assayed. Nitrogen was limiting in eight lakes and constituents other than nitrogen and phosphorus were limiting in six lakes. The results of this study indicated phosphorus limitation decreased as the productivity of the lake waters increased.

A comparison of three microbial assay procedures for measuring toxicity of chemical residues.

Public concern about environmental and health effects from the disposal of residues from the manufacture of agricultural and industrial process chemicals into landfills led to the passage of the Comprehensive Environmental Response, Compensation and Liability Act of 1980, commonly referred to as the “Superfund” Law. One method of defining the potential toxicity of these chemical residues is the use of bioassays, a number of which use bacteria as the test organism and have been proposed to assess the impact of chemical pollutants on the environment. Efforts were directed toward the establishment of short-term methods that are inexpensive, rapid, reproducible and sensitive. A major advantage of microbial toxicity tests over chemical analysis is their direct assessement of potential biotic impact without extrapolation from chemical analysis of uncertain completeness. It was the intent of this paper to evaluate the relative sensitivity, precision, and accuracy of three published microbial bioassay procedures for ascertaining their ability to define the toxicity potential at hazardous waste sites.

Utilization of algal assays to assess the effects of municipal, industrial, and agricultural wastewater effluents upon phytoplankton production in the Snake River system

The most characteristic water quality problem of the Snake River Basin is the excessive aquatic growth and thick blooms of algae. The cause of these aquatic growths is related to the high concentrations of basic nutrients — nitrogen and phosphorus — in the Snake system. Industrial wastes, natural phosphate levels, irrigation return flows, municipal wastes, and the decay of aquatic biota all contribute to the nutrient balance which stimulates aquatic growths.Algal assays were conducted on waters of eighteen Snake River and tributary sites to: (1) determine if algal growth was consistent with results predicted from review of chemical analysis for orthophosphorus and total soluble inorganic N; (2) determine if algal yields were limited by P, N, or some other nutrient essential to algal growth; and (3) predict the effects of N or P additions on algal productivity.

ELEVATED CO2 AND TEMPERATURE ALTER THE RESPONSE OF PINUS PONDEROSA TO OZONE: A SIMULATION ANALYSIS

We investigated the potential impact of projected future temperature and CO2 concentrations in combination with tropospheric O3 on the annual biomass increment of Pinus ponderosa Doug. ex Laws. TREGRO, a process-based whole-tree growth model in which trees experienced a seasonal drought, was used to study the interactions of CO2, temperature, and O3 on tree growth along a latitudinal gradient in California, Oregon, and Washington, USA. The annual biomass increment increased in proportion to CO2 concen- tration, although the magnitude varied among sites. Increasing air temperature ( 11.38C) increased growth at most sites. Elevated CO2 increased the temperature optimum for growth at four sites and decreased it at two sites. The annual biomass increment decreased with increasing O3 exposure. The differences in O3 effects among sites were primarily controlled by differences in precipitation. Although increasing CO 2 can reduce the O3 impact, it does not eliminate the impact of O3. Elevated CO2 would enhance tree growth more if O3 exposures were reduced, especially in the more polluted sites. The greatest benefit for tree growth would come from reducing O3 exposures in the most polluted sites, but we must also consider locations that have high inherent O 3 sensitivity because of their mesic con- ditions. Limiting the increase of O 3 levels in those areas will also increase tree growth.

The effect of secondary effluents on eutrophication in Las Vegas bay, Lake Mead, Nevada

The eutrophication potential of Lake Mead, with primary emphasis on Las Vegas Bay, was determined with Selenastrum capricornutum. Nutrient limitation profiles were determined for three sampling stations in Las Vegas Bay and one in Boulder Basin. After heavy metals were chelated with EDTA, P was identified as the primary limiting nutrient with N the secondary limiting nutrient for S. capricornutum. Productivity potential was highest in upper Las Vegas Bay near the sewage inflow. Toward the mouth of the bay and in Boulder Basin, progressively lower potentials were defined. Productivity potential could not be predicted from the filtered samples because the nutrients bound up in the indigenous biomass remained on the filters. Autoclaving followed by filtration prior to assay enabled S. capricornutum to produce yields relative to the productivity observed in the lake.

Toxicological Assessment of Hazardous Waste Samples Extracted with Deionized Water or Sodium Acetate (TCLP) Leaching Media

Sodium acetate and deionized water elutriates prepared from municipal and industrial waste products, and the sodium acetate leaching media per se, recommended by the EPA for the Toxicity Characteristic Leaching Procedure (TCLP), were bioassayed for their toxicity potential. The toxicity bioassay organisms included: algae, Selenastrum capricornutum; macroinvertebrates, Daphnia magna; lettuce seed root elongation, Lactuca sativa L.; and, bacteria (Microtox), Photobacterium phosphoreum. The pH 5.0 sodium acetate leaching media was highly toxic to each of the test organisms. Adjustment of the pH to 7.0 decreased toxicity approximately 2.5-fold for algae and lettuce, and 6-fold for D. magna. This reduction, while statistically significant, did not change the toxicity classification of the sodium acetate leaching media. Photobacterium phosphoreum was un-affected by pH 7 sodium acetate leaching media after 30-minutes exposure. Toxicity of the industrial waste TCLP elutriates to D. magna and S. capricornutum was similar to that obtained in the elutriates prepared with deionized water. The response of D. magna to the TCLP elutriates from sewage sludge (POTW #2), municipal ash #1 and #2, paint sludge #2, Midco volatile soil, and First Chemical Corp. indicated that these samples contained acetate soluble contaminants which were more toxic than the sodium acetate itself. Bioassays detected toxicity in either TCLP or deionized water eluted samples. Toxicity of water eluted samples can be attributed to materials leached from the waste. Toxicity of the TCLP eluted samples is problematic due to uncertainty of the amount of toxicity attributable to the leaching media itself vs. the materials leached from the wastes.