2. Resource components 



Organism availability 

 Laboratory availability 

 Expertise required 

 Expense and time required 



3. Standardization components 



Approved standard methods 



Reference data base 



Interlaboratory validation 



Quality assurance and control criteria 



Verification components such as ecosystem relevance, sensitivity, and 

 discriminatory ability are so critical that multiple species and end- 

 points should be incorporated in testing programs for sediment toxicity 

 assessments, according to Burton (1991). Therefore we measured the 

 relative toxicity of the sediment porewater with a battery of bioassays 

 that included the following test organisms: the marine bacterium, Photo- 

 bacterium phosphoreum (Microtox''^), the freshwater alga, Selenastrum 

 capricornutum, the rotifer, Branchionus calyciflorus, the daphnid, 

 Ceriodaphm'a dubia, and the sphaerid clam, Musculium transversum. The 

 Microtox''^ assay measures the luminescence of P. phosphoreum (Bulich et 

 al . 1981). Inhibition of this luminescence is considered a toxic re- 

 sponse. The 5. capricornutum assay measures the inhibition of photosyn- 

 thetic activity of an algal culture as a measure of toxicity (Ross et 

 al . 1988). The rotifer assay is a mortality test (Snell and Personne 

 1989). The C. dubia assay was the standard USEPA (1985) acute assay 

 (48-hour mortality). The sphaerid or fingernail clam assay is based on 

 measuring changes in filtering rates. The dilution water used in the 

 toxicity tests and for maintaining the organisms was Perrier'^ bottled 

 water. 



17 



