The depuration kinetics of the domoic acid from three body parts (i) digestive gland, (ii) adductor muscle+gonad+kidney+foot and (iii) gills+mantle of the scallop Pecten maximus was studied over 154 days. The scallops, which had accumulated the toxins during a Pseudo-nitzschia australis outbreak, were obtained from a natural bed and hung from a mussel raft in two locations (front and centre) and at
three depths (2, 6 and 10 m). The time course of the depuration of domoic
acid (DA), as well as the environmental variables, were monitored throughout the
experiment. The whole body depurated the toxin very slowly (ca 0.007
day−1) decreasing its concentration from ca. 3200 µg DA g−1.
Its kinetics was driven mostly by the digestive gland, which accounted for
ca. 95% of the total toxin burden from the start of the experiment.
Suspending the scallops from a raft increased the depuration rate of the
whole body and digestive gland (ca. 30%) and of the edible tissues
(15%). Increases of the depuration rate of domoic acid seem to be related
to the pair of covariating variables temperature-salinity. Food amount does
not seem to have a significant effect.