The Mytilus edulis larvae test appears to have relatively high sensitiivity, 

 precision, and discriminatory power; it has been sufficiently developed to warrant 

 its use in screening studies of sediment toxicity; but the influence of sediment texture 

 and organic carbon content should be evaluated in controlled laboratory experiments. 



A quick procedure for accurately counting the number of M. edulis embryos inoculated 

 into the test chambers at the initiation of the tests should be developed to help 

 reduce the variance in the end-point of survival. 



Many of the whole-embryo Strongylocentrotus purpuratus test end-points appear to be 

 less sensitive than those measured with M. edulis, but the cytogenetic/ mitotic end- 

 points should be evaluated further as indicators of mutagenicity in environmental 

 samples. 



The relatively highly tested and developed Rhepoxynius abronius test is very 

 sensitive and the influence of fine-grained sediments upon the organism has been 

 quantified in controlled laboratory expeiments; the test should be used further in 

 assessments of sediment quality. 



The relatively new test with Ampelisca abdita appears to be less sensitive than some 

 of the others including that with R. abronius, but appears to be particularly suitable 

 for testing the toxicity of fine-grained sediments; it should be used in assessments of 

 sediments known or suspected to be highly contaminated; and a source of non-toxic 

 native sediments should be located for use as controls. 



In both the R. abronius and A. abdita tests, emphasis should be placed upon the 

 survival end-point; the avoidance end-point has very high within-sample variance, 

 resulting in relatively low sensitivity; and the reburial end-point with R. abronius is 

 insensitive and should be discontinued. 



Better methods of extracting sediment pore water that reduce the amount of organic 

 contaminants that are removed from the pore water should be developed to enhance 

 the utility of pore water tests; other tests of reproductive success such as that 

 measured with Dinophilus gyrociliatus should.be developed. 



More emphasis should be placed upon the development of sediment toxicity tests in 

 which mutagenicity is determined and in which reproductive success is determined. 



The benthic community samples from the Oakland Inner Harbor site should be 

 analyzed to determine if the composition data confirm the toxicity test data. 



The survey of sediment quality performed in San Francisco Bay with the profiling 

 photography should be repeated at selected sites where it appeared that the 

 sediments and benthic communities were in transition to determine temporal trends. 



The cytochrome P-450 measures and micronuclei counts, together, appear to provide a 

 suite of sensitive indicators of both exposure to and effects of certain hydrocarbons, 

 including those that may be readily metabolized and not detected in fish; the 

 enzymes may reflect recent expsoures to toxicants, whereas the micronuclei may 

 integrate the effects of exposures over periods of several months; they should be used 

 in assessments of marine environmental quality where the presence of hydrocarbons 

 is known or suspected. 



96 



