Mechanism of radium-226 transfer from sediments and water to marine fishes.

Radiometric age confirmation and growth of a deep-water marine fish species: The bank rockfish, Sebastes rufus

“…Porntepkasemsan and Nevissi (1990) noted that 226 Ra levels were five times higher for pelagic species (chum salmon, Oncorhynchus keta and coho salmon, Oncorhynchus kisutch; Jenkins, 1969) than for several benthic marine fishes. Based on this comparison, they concluded that 226 Ra is most likely taken up by fish through water and food, not the sediments from which it originates, and that the higher 226 Ra activities found in salmon were probably due to their high metabolic rate.…”

“…Use of the 210 Pb/ 226 Ra technique to age fishes is based on the incorporation of 226 Ra (half-life 1622 years) into otolith material as a calcium analogue (Porntepkasemsan and Nevissi, 1990;Smith et al, 1991), and the subsequent decay to its daughter product 210 Pb (half-life 22.3 years). Because of the short half-lives of the intermediary radionuclides involved in the series ( 222 Rn, 218 Po, 214 Pb, 214 Bi, 214 Po, cumulative decay half-lives < 4 days), 226 Ra can be thought to decay directly to 210 Pb.…”

Radiometric age validation of golden redfish (Sebastes marinus) and deep-sea redfish (S. mentella) in the Northeast Atlantic

“…As metabolic rates of pelagic redfish are not known, this effect could not be evaluated in this study. Furthermore, Porntepkasemsan and Nevissi (1990) investigated Ra contents in the fish body, which is subject to other uptake rates as observed in otoliths (Campana, 1999). The high 226 Ra values measured in the sample S1, containing whole otoliths of 0-group redfish, could point to elevated levels of Ra uptake in the very early life stages, apart from environmental influences (Andrews et al, 1999a).…”

“…The mechanisms of Ra uptake by marine fishes were examined by Porntepkasemsan and Nevissi (1990), noting that 226 Ra levels previously found in Pacific salmon were five times higher than the values they found in several demersal species in Puget Sound off the Eastern US coast. Since salmon are pelagic, a coincidence of their findings with the elevated 226 Ra activities in pelagic redfish is plausible.…”

Determination of concentration factors for Cs-137 and Ra-226 in the mullet species Chelon labrosus (Mugilidae) from the South Adriatic Sea

“…Concentration factors (CFs) for transfer of cesium and radium from water to fish were also determined (Porntepkasemsan and Nevissi, 1990;Hameed et al, 1997;etc. ), and showed a considerable ability for fish to accumulate some radionuclides from water even when they were present in very small concentrations.…”