Methodological basis for the optimization of a marine sea-urchin embryo test (SET) for the ecological assessment of coastal water quality

The Distribution of the MusselMytilusSpecies Along the Norwegian Coast

“…Detailed descriptions of methods and applications are available for bivalves (Woelke, 1961;Thain, 1991;His et al, 1999) and sea-urchins (ASTM, 1995;Carr, 1998;Saco-Álvarez et al, 2010). Gametes are obtained from mature adults either by stripping or thermally induced spawning, fertilized in vitro in a measuring cylinder and delivered into the experimental samples.…”

“…Some threshold toxicity values for seaurchin and bivalve embryos are available in the literature (Knezovic et al, 1996), but further research is strongly needed on this topic. For NH3 Saco-Álvarez et al (2010) obtained an EC10 of 68.4 µg/L and a NOEC/LOEC of 40/80 µg/L using Paracentrotus lividus.…”

“…Their identification even depends on the position of the larva under the microscope. An alternative endpoint for the sea-urchin test was recently proposed by Saco-Álvarez et al (2010), who measure the size increase in 48 h. This avoids lengthy and subjective microscopical inspection, speeding up test readings, makes automatic reading feasible, and allows a more than twofold increase in sensitivity compared to the classical morphological endpoint.…”

“…When using this quantitative approach with seaurchins, larval length after 48 h, or even better, size increase from fertilized egg after 24 h, is preferred to percentage of normal larvae. This is because size increase is a more sensitive -and thus more discriminant-response than morphologically normal development (Saco-Álvarez et al, 2010).…”

“…This is particularly important in the case of pore waters from highly reduced sediments, which broadly depart from those values. In the case of sea urchins Saco-Álvarez et al (2010) described the optimal range for salinity from 31 to 35, and from 7.0 to 8.5 for pH.…”