Mysid shrimp bioassay

The mysid shrimp, Mysidopsis bahia, is the test organism for the liquid and suspended particulate phases. This species has been shown to be exceptionally sensitive to toxic substances and is considered to be a representative marine organism for bioassay testing by EPA. An LCj, is determined the suspended particulate phase (SPP) bioassay tests.  [c.685]

Mud Toxicity Test. Presently, the only toxicity test for drilling fluids having an EPA approval is the Mysid shrimp bioassay. The test was developed in the mid-1970s as a joint effort of the EPA and the oil industry.  [c.683]

The most significant change in the regulations on discharges of drilling fluids and cuttings in the Gulf of Mexico occurred in July 1986 when a new toxicity-based limit was placed on disposal (167). The specific toxicity limit is based on a 96-h bioassay test in which the drilling fluid is diluted with nine parts seawater and mixed well, the suspension is allowed to settle for one hour, and the suspended particulate phase (SPP) is decanted for testing. Mysid mjsidopsis bahid) shrimp are exposed to a range of SPP concentrations and the lethal concentration to 50% of the shrimp (LC q) is calculated from the observed shrimp mortaUty at the end of 96 hours.  [c.184]

Standard Handbook of Petroleum and Natural Gas Engineering Volume 1 (1996) -- [ c.683 , c.684 ]