Indicator species

Indicator Chemical name Dissociation constants and colors of free indicator species Colors of metal-indicator complexes Applications... 

Because they are weak acids or bases, the iadicators may affect the pH of the sample, especially ia the case of a poorly buffered solution. Variations in the ionic strength or solvent composition, or both, also can produce large uncertainties in pH measurements, presumably caused by changes in the equihbria of the indicator species. Specific chemical reactions also may occur between solutes in the sample and the indicator species to produce appreciable pH errors. Examples of such interferences include binding of the indicator forms by proteins and colloidal substances and direct reaction with sample components, eg, oxidising agents and heavy-metal ions. 

Parsons-Zobel plot Measurements of the extent of monolayer adsorption of an indicator species 226-231... 

The relationship between biomarker responses and effects at the population level can be tested in both field experiments and more controlled experiments in mesocosms. It may be possible to define thresholds for biomarker assays performed on indicator species, above which population effects have been shown to occur. Indicator species may be either free living or deployed. The advantage of the latter is... 

Apart from the use of this approach to study the ecotoxicology of neurotoxic pollutants in the field, it also has potential for use during the course of environmental risk assessment. An understanding of the relationship between biomarker responses to neurotoxic compounds and effects at the population level can be gained from both field studies and the use of mesocosms and other model systems. From these it may be possible to define critical thresholds in biomarker responses of indicator species above which population effects begin to appear. In the longer term, this approach... 

Fish are generally more susceptible to poisoning than microscopic plants or other animals as such they are a good indicator species. A summary of the concentrations of selected substances at which toxic effects have been detected in bacteria, algae, crustacia and protozoa is given in Table 16.14. 

Polagraphic evidence indicates species II to have a 2 Cr 1 substrate molecule ratio. 

Concerning indicator species, as a preliminary assessment in describing the wildlife component of a mercury monitoring network, based on criteria evaluated in Section 5.5 and studies cited herein, additional concerns noted above, and professional judgment of the authors, candidate wildlife species for inclusion in such a network have been selected and are indicated in Table 5.4. 

Doka SE, McNicol DK, Mallory ML, Wong I, Mirms CK, Yan ND. 2003. Assessing potential for recovery of biotic richness and indicator species due to changes in acidic deposition and lake pH in five areas of southeastern Canada. Environ Monit Assess 88 53-101. 

Gaines KF, Romanek CS, Boring CS, Lord CG, Gochfeld M, Burger J. 2002. Using raccoons as an indicator species for metal accumulation across trophic levels — a stable isotope approach. J WUdl Manage 66 811-821. 

For biological indicator species, several additional criteria are pertinent. The chosen indicators should ... 

This approach requires frequent visits to the nest or filming the feeding behavior of smdy species to guide human collection of food items. Although the former process is a direct measure, both procedures allow reliable assessment of pesticide ingestion by indicator species. 

Table 5.7 Typical annual milk yields as well as time lapse between generation of the transgene embryo and first product harvest (first lactation) of indicated species...

These studies indicate species differences in sperm damage resulting from exposure to 1,2-dibromoethane. 

Table I shows the number of experiments done, age of plants, kind of extract, its concentration, and indicator species utilized in each experiment.

Table I. Number or Experiments, Kind and Concentration of Extracts, Ages of Plants, and Indicator Species Utilized to Detect Allelopathic Potential of Brassica campestris L. and Brassica oleracea var. italica...

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