Toxicity study of the oil dispersant Corexit 9527 on Prawns - Macrobrachium rosenbergii (de Man) egg hatchability by using a flow-through bioassay tec

[Sally Furniss]

Toxicity study of the oil dispersant Corexit 9527 on Macrobrachium rosenbergii (de Man) egg hatchability by using a flow-through bioassay technique

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A. T. Law

Faculty of Fisheries and Marine Science, Universiti Pertanian Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
Received 5 October 1993;
accepted 4 March 1994. ;
Available online 20 April 2000.

Abstract

The effect of the oil-spill dispersant Corexit 9527 on egg-hatching rate of Macrobrachium rosenbergii (de Man) was studied by using an innovated flow-through bioassay technique. This bioassay method relies on the fact that M. rosenbergii fertilized eggs when detached from the mother prawn were able to hatch artificially. The flow-through system generated a stable and good water quality environment for hatching the eggs successfully. The Corexit 9527 had a pronounced effect on hatching rate of the M. rosenbergii eggs. In the control, the hatching rate of the eggs was 95?55% ? 1?74%. However, it was reduced drastically with increasing concentrations of Corexit 9527. A 100% inhibition of egg hatchability was found when the level of Corexit 9527 was higher than 250 mg litre−1. The EC50 and the EC95 values estimated by the probit method were 80?4 ? 5?5 mg litre−1 and 193?5 ? 39?9 mg litre−1 respectively (P = 0?05). The recommended safety level of Corexit 9527 for M. rosenbergii in Malaysian estuarine waters is below 40 mg litre−1.


http://www.sciencedirect.com/scienc...serid=10&md5=763fb24164aa9240c312b53d70727bf9

 

[LaMenchos]

Re: Toxicity study of the oil dispersant Corexit 9527 on Prawns - Macrobrachium rosenbergii (de Man) egg hatchability by using a flow-through bioassay technique

<a title="View Oil Spill Dispersant (COREXIT ?EC9500A and EC9527A) Information for Health Professionals on Scribd" href="http://www.scribd.com/doc/32431847/Oil-Spill-Dispersant-COREXIT-?EC9500A-and-EC9527A-Information-for-Health-Professionals" style="margin: 12px auto 6px auto; font-family: Helvetica,Arial,Sans-serif; font-style: normal; font-variant: normal; font-weight: normal; font-size: 14px; line-height: normal; font-size-adjust: none; font-stretch: normal; -x-system-font: none; display: block; text-decoration: underline;">Oil Spill Dispersant (COREXIT ?EC9500A and EC9527A) Information for Health Professionals</a> <object id="doc_212975496989031" name="doc_212975496989031" height="600" width="100%" type="application/x-shockwave-flash" data="http://d1.scribdassets.com/ScribdViewer.swf" style="outline:none;" > <param name="movie" value="http://d1.scribdassets.com/ScribdViewer.swf"> <param name="wmode" value="opaque"> <param name="bgcolor" value="#ffffff"> <param name="allowFullScreen" value="true"> <param name="allowScriptAccess" value="always"> <param name="FlashVars" value="document_id=32431847&access_key=key-11kq8iri336z7vj36nfi&page=1&viewMode=list"> <embed id="doc_212975496989031" name="doc_212975496989031" src="http://d1.scribdassets.com/ScribdViewer.swf?document_id=32431847&access_key=key-11kq8iri336z7vj36nfi&page=1&viewMode=list" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" height="600" width="100%" wmode="opaque" bgcolor="#ffffff"></embed> </object>

 

[Pathfinder]

Re: Toxicity study of the oil dispersant Corexit 9527 on Prawns - Macrobrachium rosenbergii (de Man) egg hatchability by using a flow-through bioassay technique

DATE: July 01, 2010 17:28:55 CST

EPA Releases First Round of Toxicity Testing Data for Eight Oil Dispersants


WASHINGTON ? The US Environmental Protection Agency today released peer reviewed results from the first round of its own independent toxicity testing on eight oil dispersants. EPA conducted testing to ensure that decisions about ongoing dispersant use in the Gulf of Mexico continue to be grounded in the best available science.

EPA?s results indicated that none of the eight dispersants tested, including the product in use in the Gulf, displayed biologically significant endocrine disrupting activity. While the dispersant products alone ? not mixed with oil - have roughly the same impact on aquatic life, JD-2000 and Corexit 9500 were generally less toxic to small fish and JD-2000 and SAF-RON GOLD were least toxic to mysid shrimp. While this is important information to have, additional testing is needed to further inform the use of dispersants.

"EPA is performing independent tests to determine the potential impacts of various dispersants. We will continue to conduct additional research before providing a final recommendation, " said EPA Administrator Lisa P. Jackson. "We want to ensure that every tool is available to mitigate the impact of the BP spill and protect our fragile wetlands. But we continue to direct BP to use dispersants responsibly and in as limited an amount as possible."

EPA continues to carefully monitor BP?s use of dispersant in the Gulf. Dispersants are generally less toxic than oil and can prevent some oil from impacting sensitive areas along the Gulf Coast. EPA believes BP should use as little dispersant as necessary and, on May 23, Administrator Jackson and then-Federal On-Scene Coordinator Rear Admiral Mary Landry directed BP to reduce dispersant usage by 75 percent from peak usage. EPA and the Coast Guard formalized that order in a directive to BP on May 26. Over the next month BP reduced dispersant use 68 percent from that peak.

Before directing BP to ramp down dispersant use, EPA directed BP to analyze potential alternative dispersants for toxicity and effectiveness. BP reported to EPA that they were unable to find a dispersant that is less toxic than Corexit 9500, the product currently in use. Following that, EPA began its own scientific testing of eight dispersant products on the National Contingency Plan Product Schedule (NCP-PS). Those dispersant products are: Dispersit SPC 1000, Nokomis 3-F4, Nokomis 3-AA, ZI-400, SAF-RON Gold, Sea Brat #4, Corexit 9500 A and JD 2000. Today?s results represent the first stage of that effort.


EPA tested these eight products for endocrine disrupting activity and potential impacts on small fish and mysid shrimp. The testing found:

• None of the eight dispersants tested displayed biologically significant endocrine disrupting activity.
• While all eight dispersants alone ? not mixed with oil ? showed roughly the same effects, JD-2000 and Corexit 9500 proved to be the least toxic to small fish, and JD-2000 and SAF-RON GOLD were the least toxic to the mysid shrimp.

The next phase of EPA?s testing will assess the acute toxicity of multiple concentrations of Louisiana Sweet Crude Oil alone and combinations of Louisiana Sweet Crude Oil with each of the eight dispersants for two test species.

To view the first round of test results please visit: www.epa.gov/bpspill/dispersants




For information about the response effort, visit www.deepwaterhorizonresponse.com.

http://www.deepwaterhorizonresponse.com/go/doc/2931/731363/

 

[LaMenchos]

Re: Toxicity study of the oil dispersant Corexit 9527 on Prawns - Macrobrachium rosenbergii (de Man) egg hatchability by using a flow-through bioassay technique

More on the topic of dispersant test results in: http://www.flutrackers.com/forum/showthread.php?p=361821