Effects on the Photosynthetic Activity of Algae after Exposure to Various Organic and Inorganic Pollutants: Review

Abstract

Algal studies remain necessary for risk assessment and their utility in ecotoxicology is the evaluation of lethal and sub-lethal toxic effects of potential toxicants on inhabitants of several ecosystems. Effects on algal photosynthetic apparatus caused by various chemical species have been extensively studied. The present chapter summarizes the published data concerning the toxicity of various organic and inorganic pollutants such as oils, pesticides, antifoulants and metals on photosynthesis of aquatic primary producers. Biochemical mode of action resulting in the disruption of photosynthesis depends on the chemical's nature and the characteristics of the exposed microorganism. Observed differences in response and sensitivity by different species to the same toxicant were attributed to several algal characteristics including photosynthetic capacity, pigment type, cellular lipid and protein content, and cell size. Single species bioassays either for one chemical alone or in mixture have been well reported and tolerance of both marine and freshwater water-column phytoplaktonic species has been examined. Adequate published information on multispecies tests (communities) in laboratory and field studies exists. However, risk assessment on photosynthesis of microbenthic periphyton is inadequate, though it is essential especially for hydrophobic organic molecules. Further studies are required to evaluate the adverse effects of metabolites on aquatic microalgae.

Toxic Effects of the Organophosphorus Insecticide Fenthion on Growth and Chlorophyll Production Activity of Unicellular Marine Microalgae Tetraselmis suecica: Comparison between Observed and Predicted Endpoint Toxicity Data

“…Therefore, fenthion is not expected to be a direct inhibitor of pigment synthesis nor to induce a direct oxidative stress as a consequence of its biochemical mode of action that would destroy chlorophyll pigments. However, pigment content may change in response to the cascade of events following contamination with the pesticide, regardless of its different mode of action [28,29].…”

Phycoremediation of hydrocarbon using two marine seaweeds from the Bay of Bengal coast of India

“…Oil spills in aquatic environments originate due to biogenic, natural geologic and anthropogenic activities [5][6][7][8][9].…”

“…They are found to be difficult to clean up and predominant constituents present in crude oil sediment and marine environment for a prolonged period [10]. Ecological effects of accidental oil spills is a challenging subject of both laboratory and field research [5].…”

“…Several study reports say that penetration of oil into the fur of mammals and plumage of birds results in the reduction of their insulating ability which leads them more vulnerable to temperature fluctuation, hypothermia and their buoyancy to water becomes diminished. Environmental effects of oil spills and its resulting toxicity in the sea have received the attention of public, student and scientific community [5]. Usually, animals find their offsprings babies using their body odor, which vanishes of, due to the strong aroma of the crude oil, in turn, becomes a root cause for the rejection of their offsprings leading to the condition of starving and die.…”

“…It is really a heartbreaking threat that the oilsoaked birds even after cleaning less than one percent of the birds can only survive. Crude oil is highly toxic which comprises of 10,000 different types of both aliphatic and aromatic hydrocarbons, which causes severe threats to the marine ecosystem whenever oil spills occur in the marine environment [5].…”