Advance in the toxic effects of petroleum water accommodated fraction on marine plankton

Recently, the impact of petroleum pollution on marine plankton has been complemented by a great concern. This review summarizes the reports about toxic effects of oil water accommodated fraction (WAF) on marine phytoplankton, zooplankton and early life stage of animal. For the oil WAF, toxicants are mainly composed of the aromatic hydrocarbons, such as the benzene hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) with 2–5 rings. The oil WAF, especially the PAHs, can be accumulated in plankton due to their great lipophilic abilities, and thus elicites various deleterious effects. Toxicological tests show that marine plankton is very sensitive to the petroleum WAF, as the order of median effective/lethal concentration is merely μg/L or mg/L. There are species and developmental stages differences of plankton tolerance to petroleum WAF, and the toxicity of different oil WAF is various. Generally, its toxicity enhances with increasing carbonic chain length and benzene ring number. Many studies on the acute and sub-acute toxic effects of oil WAF have been done, however few researches on its chronic toxic effects has been carried out till now. Besides, most reports focused on the levels from molecule to individual, though very little work of petroleum toxic effects has ever been performed on the marine plankton population or community levels. Therefore, it is necessary to continue these studies in future.