|Fuel oils: chemical characterization and toxicity to microalgae|
Winters, K.; Batterton, J.C.; O'Donnell, R.; Van Baalen, C. (1977). Fuel oils: chemical characterization and toxicity to microalgae, in: Giam, C.S. (Ed.) Pollutant effects on marine organisms. pp. 167-189
In: Giam, C.S. (Ed.) (1977). Pollutant effects on marine organisms. Lexington Books: Lexington. ISBN 0-669-01518-0. XI, 215 pp., more
|Authors|| || Top |
- Winters, K.
- Batterton, J.C.
- O'Donnell, R.
- Van Baalen, C.
Our objectives throughout this study have been to identify compounds occurring in water soluble fractions from fuel oils and to examine these compounds for possible toxicity to microalgae. The use of microalgae as bioassay organisms is justified by their importance as primary producers in the marine environment. Basic to an objective assessment of effects of petroleum on primary production is the development of a body of information on those compounds that inhibit the growth of microalgae . Approximately 50% of the compounds in the water solubles from four fuel oils have been identified by gas chromatography and mass spectrometry .We have found phenols, anilines, indoles, pyridines, quinolines, and thiophenes, as weIl as the more commonly described naphthalenes and benzenes. Methylated derivatives of many of these compounds are present in relatively high concentrations. Water extracts of the four fuel oils exhibited quite different toxicity towards the growth of six representative rnicroalgae, two blue-green algae, two green algae , and two diatoms. For example, water solubles (9 ppm total organics) frorn "Baton Rouge" fuel oil had almost no effect on all six microalgae tested. However, extracts of "Montana" and "Baytown" fuel oils were lethal to blue-green algae at 4-5 ppm total organics. We believe this was in part traceable to their content of methyl anilines, particularly p-toluidine. Agmenellum quadruplicatum, Strain PR-6, a marine coccoid blue-green alga, was sensitive to 100 ppb in liquid culture. Other blue-green algae tested showed a similar sensitivity to p-toluidine. The water extract of "New Jersey" fuel oil inhibited growth of the green algae and caused lags in the growth of the blue-green algae. Thus far we have not been able to identify any compound(s) in "New Jersey" water solubles that could explain the toxicity to the green algae. On the other hand, we have identified phenalen-l-one in water extracts of an American Petroleum Institute fuel oil. Interestingly enough, phenalen-l-one has shown high toxicity (250 ppb) only towards the green algae . Growth of the two estuarine diatom test organisms was not completely inhibited by any of the fuel oil water extracts, although some lags in growth were noted. Water extracts of the four fuel oils were also quite varied in their immediate effects on photosynthesis. For instance, a water extract (7 ppm total organics) of "New Jersey" fuel oil completely inhibited the photosynthesis of the green algae Chlorella autotrophica, Strain 580, but not Strain PR-6, a blue-green alga. However, the growth of both species was depressed. In comparison, a water extract (9.5 ppm total organics) of "Baytown" fuel oil did not depress photosynthesis or growth of 580, the diatom Cylindrotheca sp., Strain N-1, or photosynthesis of PR-6; yet growth of PR-6 was inhibited. None of the compounds we have found that inhibit algal growth caused an immediate depression in photosynthesis. Our experiments with light aromatics such as benzene, toluene, and xylene do show an immediate but temporary inhibition of photosynthesis if very high concentrations (10 ppm) are used. We believe our type of growth system, open test tubes with continuous aeration, should rapidly purge the more volatile compounds from the water extracts of whole fuel oils. Thus our observations of toxic effects under these conditions indicate that the less volatile, more polar compounds are cause for concern. The variable toxicity of fuel oils and the unpredictable algal response suggest caution in generalizing on the toxicity or lack thereof of petroleums to phytoplankton.