Sea urchin fertilization assay: an evaluation of assumptions related to sample salinity adjustment and use of natural and synthetic marine waters for testing.
Most industrial effluents discharged into the marine coastal environment are freshwater in nature and therefore require manipulation prior to testing with marine organisms. The sea urchin fertilization test is a common marine bioassay used for routine environmental monitoring, investigative evaluations, and/or regulatory testing of effluents and sediment pore waters. The existing Canadian and U.S. Environmental Protection Agencies test procedures using sea urchin (and sand dollar) gametes allow for sample salinity adjustment using either brine or dry salts. Moreover, these procedures also allow for the use of either natural or synthetic marine water for culturing/holding test organisms and for full-scale testing. At present, it is unclear to what extent these variables affect test results for whole effluents. The test methods simply state that there are no data available and that the use of artificial dry sea salts should be considered provisional. We conducted a series of concurrent experiments aimed at comparing the two different treatments of sample salinity adjustment and the use of natural versus synthetic seawater in order to test these assumptions and evaluate effects on the estimated end points generated by the sea urchin fertilization sublethal toxicity test. Results from these experiments indicated that there is no significant difference in test end points when dry salts or brine are used for sample salinity adjustment. Similarly, results obtained from parallel (split-sample) industrial effluent tests with natural and artificial seawater suggest that both dilution waters produce similar test results. However, data obtained from concurrent tests with the reference toxicant, copper sulfate, showed higher variability and greater sensitivity when using natural seawater as control/dilution water.
Jonczyk
E
E
BEAK International, Brampton, Ontario, Canada.
Gilron
G
G
Zajdlik
B
B
D000818:Animals; D002170:Canada; D004784:Environmental Monitoring / Q000331:legislation & jurisprudence / Q000379:methods*; D005260:Female; D005306:Fertilization / Q000502:physiology; D019015:Geologic Sediments; D006077:Government Agencies; D007220:Industrial Waste / Q000032:analysis* / Q000331:legislation & jurisprudence; D008297:Male; D008954:Models, Biological; D012617:Sea Urchins / Q000502:physiology*; D012623:Seawater / Q000032:analysis*; D012965:Sodium Chloride; D013084:Sperm-Ovum Interactions / Q000502:physiology*; D014481:United States; D014484:United States Environmental Protection Agency; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D007220:Industrial Waste; D014874:Water Pollutants, Chemical; D012965:Sodium Chloride