Pollution-induced community tolerance

Blank et al. (1988) proposed that an evaluation of the tolerance of the biological communities to toxicants would be a useful indicator of toxicant impacts. 

Pollution-induced community tolerance (PICT) has been developed further and used in a number of situations (Blank 2002, Grant 2002, Boivin et al. 2002). 

The fundamental premise of PICT is that under toxicant stress natural selection occurs for organisms that are more tolerant to the pollutant. This increase in tolerance can occur at the level of the population by the induction of tolerance mechanisms by individuals or by selection for tolerant individuals. The biological community increases its tolerance to change imposed by the pollutant by the elimination of sensitivity individuals, populations, or species and the addition of tolerant organisms. 

PICT can be determined by a variety of means. An increase in number of organisms tolerant to specific toxicants can be enumerated. The presence of biodegradative genes in prokaryotic organisms can be used as an indicator of selection. A resistance to change at the community level upon subsequent toxicant stressors is an indication or PICT. This is a measure easily examined in microcosm systems. 

The difficulty in applying PICT is the difficulty of attributing causality to the observed correspondence in the field. This can be accomplished by measuring the concentration of the pollutant, using specific markers that are indicative to the mode of action, and using multiple lines of investigation to connect exposure and effect. 

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McClellan K, Altenburger R, Schmltt-Jansen M (2008) Pollution-induced community tolerance as a measure of species interaction in toxicity assessment. J Appl Ecol 45 1514... 

Schmitt-Jansen M, Altenburger R (2005) Predicting and observing responses of algal communities to photosystem Il-herbicide exposure using pollution-induced community tolerance and species-sensitivity distributions. Environ Toxicol Chem 24 304... 

Schmitt H, Flaapakangas H, van Beelen P (2005) Effects of antibiotics on soil microorganisms time and nutrients influence pollution-induced community tolerance. Soil Biol Biochem 37 1882-1892... 

Pollution-induced community tolerance has been observed in ecoystems in which communities that are resistant to the effects of some kinds of pollutants have survived. Additional exposure to the same pollutants may have relatively little effect because the organisms that have survived are those that tolerate the particular kinds of pollutants in question. 

Explain why observation of deaths of organisms and resultant declines in populations, though straightforward and unequivocal, are often insufficient to fully explain the effects of toxic substances on ecosystems. Why is it important to have the capability to study sublethal effects Certain sheep that have been raised for centuries in coastal areas of Scotland exist on a diet of seaweed that is high enough in arsenic to kill other kinds of sheep. Does this observation illustrate pollution-induced community tolerance Explain. 

Blanck H. 2002. A critical review of procedures and approaches used for assessing pollution-induced community tolerance (PICT) in biotic communities. Human Ecol Risk Assess 8 1003-1034. 

Blanck H, Dahl B. 1996. Pollution-induced community tolerance (PICT) in marine periphyton in a gradient of tri-n-butyltin (TBT) contamination. Aquat Toxicol 35 59-77. 

Molander, S. and H. Blanck. 1992. Detection of pollution-induced community tolerance (PICT) in marine periphyton communities established under diuron exposure. Acjuat. Toxicol. 22 129-144. 

Patterns should be in common. Although exact prediction may be problematic and the idea of recovery an illusion, certain patterns should be detectable. The increase in tolerance, often observed as pollution-induced community tolerance, is one such example. Several potential outcomes may be possible, but not every outcome. Perhaps, as a better understanding of the assembly of ecosystems develops, we can even predict the probabilities of the outcomes. Prediction of ecological impacts will resemble more the weather forecast than the Newtonian dynamics. 

Blank, FL, S.-A. Wangberg, and S. Molander. 1988. Pollution-induced community tolerance — a new ecotoxicological tool. In Functional Testing of Aquatic Biota for Estimating Hazards of Chemicals, ASTM 988. J. Cairns, Jr. and J.R. Pratt, Eds. American Society for Testing and Materials, Philadelphia, PA, pp. 219-230. 

Boivin, M.Y., A.M. Breure, L. Posthuma, and M. Rutgers. 2002. Determination of field effects of contaminants-significance of pollution-induced community tolerance. Hum. Ecol. Risk Assess. 8 1035-1055. 

Describe the concept of pollution-induced community tolerance (PICT) ... 

Rutgers, M., van t Verlaat, I.M., Wind, B., Posthuma, L. and Breure, A.M. (1998) Rapid method for assessing pollution-induced community tolerance in contaminated soil. Environmental Toxicology and Chemistry, 17, 2210-2213. 

A variety of ecological parameters were determined (Table 9.4). Many parameters differed from the reference sample of field A (like the pollution-induced community tolerance (PICT) results) and showed an increase compared with the reference field, but this can be attributed at least partly to increased organic carbon... 

An interesting assay has been developed that uses communities of naturally occurring algae. The assay is based on the concept of pollution-induced community tolerance (PICT) (Blanck et al. 1988) whereby exposure to a toxicant results in the elimination of sensitive species and the dominance of tolerant ones quantification is achieved by using short-term assays for the inhibition of photosynthesis under laboratory conditions (Blanck and Wangberg 1988). One of the attractive features of the system is that it can be used in widely different situations ranging from microcosms and mesocosms to natural ecosystems. 

Rutgers, M. Breure, A.M. (1999) Risk assessment, microbial communities, and pollution-induced community tolerance, Human and Ecolological Risk Assessment, 5(4), 661-670. 

Siciliano SD et al., Assessment of 2,4,6-trinitrotoluene toxicity in field soils by pollution induced community tolerance (PICT), denaturing gradient gel electrophoresis (DGGE) and seed germination assay, Environ. Toxicol. Chem., 19, 2154, 1999. 

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