TEMPERATURE EFFECTS ON UPTAKE AND RETENTION OF CONTAMINANT RADIONUCLIDES AND TRACE-METALS BY THE BRITTLE STAR OPHIOTHRIX FRAGILIS

Recent revelations of extensive dumping of radioactive wastes in Arcti c seas emphasize the need to understand the processes affecting accumu lation of contaminants in polar marine food webs. Little is known, how ever, about the effects of low temperatures on bioaccumulation of radi onuclides and toxic metals. To address this question, we examined the effects of temperature on uptake and retention of 11 dissolved radiois otopes (including both nuclear waste components and required, and toxi c metals) by the brittle star Ophiothrix fragilis, typical of species which dominate Arctic benthic communities. Lower temperatures signific antly reduced uptake rates of all elements examined, but had little ef fect on loss rates. These results raise questions about the validity o f extrapolating previous work on biological dynamics of dissolved cont aminants, largely carried out at temperate zone temperatures, to polar ecosystems. This work suggests that the effects of low Arctic tempera tures may need to be taken into consideration in order to understand t he potential for food chain accumulation of nuclear wastes and toxic m etals in high-latitude seas. Copyright (C) 1996 Elsevier Science Ltd.