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Acute toxicity of crude and dispersed oil to octopus pallidus (Hoyle,1885) hatchlings 原油及分散劑對章魚苗之急性毒性試驗. Sara M. Long , Douglas A. Holdway WATER RESEARCH (2002) 36:2769-2776 Reporter: Bei-Chan Liu. Introduction.
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Acute toxicity of crude and dispersed oil to octopus pallidus (Hoyle,1885) hatchlings原油及分散劑對章魚苗之急性毒性試驗 Sara M. Long , Douglas A. Holdway WATER RESEARCH (2002) 36:2769-2776 Reporter: Bei-Chan Liu
Tanker accidents release approximately one third of the 1.18 million metric tonnes of petroleum hydrocarbons that enter the aquatic environment worldwide each year. Example: The Exxon Valdez in Alaska in 1989 The Sea Empress in Pembrokeshire in 1996 2001年台灣阿瑪斯號 2005年台灣宜蘭吉尼號 Introduction
In situ buring Chemical dispersants Clean-up method
Octopus pallidus O. pallidus is a common species of octopus that ranges from the central Great Australian Bight to central New South Wales.
Octopus traps were laid off the coast at Portarlington,Port Phillip Bay,Victoria, at a depth of 14m, in April 1998. • The majority of females had laid eggs in their traps; the remaining females laid eggs whilst captured.
The lab-experiments are designed to be relevant both for produced water releases as well as for oily exposed water created in oil spill situations. Water-accommodated fraction (WAF)
Gas Chromatography Determine total petroleum hydrocarbon (TPH) concentration
Ten recently hatched (24–96 h post hatch) O. pallidus Twenty recently hatched (24–96 h post hatch) O. pallidus WAF Control tank Dispersed -WAF Mortality was recorded daily.
濃度效應曲線 24h 50% Lethal Concentration (LC50):24小時半數致死濃度 No observable effects concentration (NOEC)無觀察效應濃度 lowest observable effect concentration (LOEC) 最低觀察效應濃度
500nm measure • Toxicity studies were also conducted using 4-chlorophenol as a reference toxicant. • Analysis of 4-chlorophenol was based on the method described by Clesceri et al. Potassium ferricyanide Phenolic compounds 4-aminoantipyrine At PH7.9 At room temperature for 15 min.
Below the limit of detection 10-fold
O. pallidus hatchlings were more sensitive to exposure to WAF alone compared to dispersed-WAF.
Younger hatchlings were more sensitive to exposure than older hatchlings in dispersed-WAF for both the 24 and 48 h-LC50.
Toxicity tests Dispersed-WAF was significantly less toxic than WAF alone to O. pallidushatchlings.
O. Pallidus hatchlings Hydra viridissima (Mitchell et.al) Dispersed-WAF was significantly less toxic than WAF.
WAF was highly toxic to O. pallidus hatchlings over the first 24 h of exposure, compared to dispersed-WAF. The CV increasing from 14 to 68. A study showed that there was no significant increase in 96-h and 7-day LC50 values of fathead minnow exposed to benzene. The lethal effect of benzene upon the fathead minnow occurred mostly in the first days of exposure.
TPH concentration Chemical analysis ×10 Addition of dispersants Increasing in the heavier, less water-soluble hydrocarbons, such as PAHs(多環碳氫化合物). Dispersed- WAF
PAHs • The higher molecular weight • low acute toxicity Low aqueous solubility • Light crude oil, • The water-soluble aromatic • hydrocarbons account for up to • 45% of total hydrocarbons Bass Strait crude oil
Addition of Corexit 9527 resulted in 1.An increase in the TPH present in the solution. 2. No increase in the toxic,lower molecular weight hydrocarbons.
Effect of age upon toxicity The digestive glands in O. pallidus hatchlings in the present study may not have had the ability to metabolise petroleum hydrocarbons.
Sensitivity of O. pallidus to toxicants Difference in sensitivity may also be as a result of using early life stages in the present study as well as species sensitivity.
Petroleum hydrocarbons present in the water column after addition of chemical dispersants were not in the form that was toxic to, in this case, O. pallidus. The lower molecular weight hydrocarbons, the concentration of which was not increased by addition of Corexit 9527, may be the more toxic components of WAF alone. Application of chemical dispersants to an oil spill is unlikely to adversely affect O. pallidus and possibly other benthic species.
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