An experimental study on the Dioaccumulation and turnover of polonium-210 and lead-210 in marine shrimp

Abstract

The experimental accumulation of 210Po and 'lOPb from seawater alone and from seawater and food was studied in the laboratory with the benthic shrimp Lysrnata seticaudata. Shrimp accumulated both radionuclides from water for 21 d, reaching whole body concentration factors [CF = (Bq g-' of shrimp wet wt)/(Bq ml-' filtered water)] of 139 k 28 for "OPo and 682 + 149 for 'l0Pb. When uptake was from water only, tissue analyses revealed that radionuclide accumulation was mainly due to external adsorption. Accumulation in internal tissues also occured through the intake of seawater for osmotic regulation. Exposure of shrimp to radionuclides dissolved In water and labelled food produced a noticeable accumulation of 210Po in internal tissues which was not accompanied by an identical accumulation of 210Pb. It is concluded that in shrimp 210Po was mainly accumulated from food, whereas 210Pb was largely taken up from the fraction dissolved in seawater. A much higher digestive assimilation efficiency for 210Po, about 5-fold that of ''Opb, was observed in L. seticaudata. This difference can account for the enhancement of 2'oPo:210Pb ratios observed in the lower trophic levels of marine food chains. Turnover of 2'0Po in shnmp tissues is much slower than for 2'0Pb, a fact which also contributes to the enhanced 2'o~o:2'0Pb concentration ratios observed in marine crustaceans.

Comparative bioaccumulation studies of colloidally complexed and free‐ionic heavy metals in juvenile brown shrimp Penaeus aztecus (Crustacea: Decapoda: Penaeidae)

“…Ionic species are probably adsorbed onto shrimp exoskeletons through chelation by functional groups on organic surfaces as seen with other divalent metals (Carvalho and Fowler 1993). One of our shrimp in the free-ion treatment molted shortly before the animal was to be sacrificed for sampling, and although this animal was not included in our analysis, it provided some data on the activities of the intact exoskeleton.…”

“…Results indicated that it contained a substantial proportion (Ba 9%, Sn 14%, Cd 16%, Hg 18%, Ag 21%, Fe 48%, Mn 56%, Zn 70%, and Co 72%) of the total animal activity, although we do not know how much of this activity was due to surficial adsorption. Carvalho and Fowler (1993) found that after 21 d of uptake via solution, the exoskeleton of the caridean shrimp Lysmata seticaudata accounted for 27.5 and 36% of total activity of 210 Po and 210 Pb, respectively. Only three of our animals molted, and there was no evidence that any of the animals we sampled and used for final analysis had molted.…”

“…Carvalho and Fowler (1993) found that accumulation of 210 Pb and 210 Po by the L. seticaudata was linked to intake of water for osmotic regulation and that the hemolymph of penaeid shrimp was hypo-osmotic to seawater (35 psu). To compensate for water loss by osmosis, shrimp can drink seawater.…”

“…Dissolved or suspended metals can degrade water quality and become available to plankton, nekton, and benthic filter and deposit feeders. Aquatic organisms can acquire trace elements from food, from suspended particles, or directly from the water (Luoma 1989;Luoma et al 1992;Carvalho and Fowler 1993). Uptake of dissolved metals from solution through permeable surfaces into the bodies of marine invertebrates is generally considered to be a passive process (Williams 1981), while metals associated with macroscopic particles are taken up via active ingestion.…”

Levels of Petroleum Hydrocarbons and some Heavy Metals in Tissues of <i>Tympanotonus fuscatus</i> periwinkles from Warri river of Niger Delta Area of Nigeria

“…Aquatic organisms can acquire trace elements from food, suspended particles or directly from the water (Carvalho and Fowler, 1993). Many of these pollutants are nonbiodegradable compounds and dangerous due to their innate ability to constantly remain within the ecosystem (Hernandez-Hernandez et al, 1990).…”