Effects of chronic metal exposure and sediment organic matter on digestive absorption efficiency of cadmium by the deposit-feeding polychaete Capitella species I
- Roskilde Univ. (Denmark). Dept. of Life Sciences and Chemistry
- Univ. of South Carolina, Columbia, SC (United States). Dept. of Environmental Health Sciences
Organic matter such as humic acid and bacterial slime exopolymer are common in estuarine and coastal sediments, where they are ingested by animals that process particulate detritus. Both humic acid (HA; refractory) and exopolymer (EPS; easily digestible) bind metals and therefore might represent a source of particulate-bound metals to deposit-feeding organisms. This study examined how cadmium preexposure, gut passage time (GPT), and quality and quantity of the organic coating on sediment particles interact to determine cadmium absorption efficiency (Cd-AE) in Capitella sp. I. Pulse-chase experiments using [sup 109]Cd and [sup 51]Cr were used to determine Cd-AE in individual worms. Worms were given a pulse of carbon-cleaned, HA-coated or EPS-coated sediment particles. The third treatment was divided into three EPS concentrations (high, medium, and low). A 5-d preexposure to cadmium did not affect the egestion rates during either the preexposure period or the chase phase. Worms given a pulse of carbon-cleaned particles exhibited higher egestion rates during the chase phase than worms given a pulse of organic-coated particles, and no differences were seen in egestion rate between worms exposed to HA- and high-EPS-coated particles. Egestion rates decreased with increasing EPS concentration. The presence of refractory organic material decreased the absorption efficiency of cadmium from sediment relative to Cd-AE from carbon-cleaned sediment but not relative to Cd-AE from sediment coated with a high concentration of EPS. The Cd-AE increased linearly with increasing exopolymer coating on sediment particles. Overall, Cd-AE increased with increasing gut passage time in worms that were not preexposed, although Cd-AE from HA-coated particles was independent of gut passage time. Preexposure to cadmium reversed the relationship between gut passage time and cadmium absorption efficiency. Thus, the implications are that sedimentary organic matter and worm physiology might be especially important in controlling metal bioavailability in deposit-feeding organisms and should be considered in sediment quality approaches.
- OSTI ID:
- 6479835
- Journal Information:
- Environmental Toxicology and Chemistry, Vol. 18:6; ISSN 0730-7268
- Country of Publication:
- United States
- Language:
- English
Similar Records
Geochemical influences on assimilation of sediment-bound metals in clams and mussels
Effects of development mode, contaminated sediments, and maternal characteristics on growth and reproduction in the polychaetes Streblospio benedicti (Spionidae) and Capitella sp. I (Capitellidae)
Related Subjects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BIOLOGICAL AVAILABILITY
CADMIUM
CHRONIC EXPOSURE
HUMIC ACIDS
INTESTINAL ABSORPTION
SEDIMENTS
WATER POLLUTION
ABSORPTION
ELEMENTS
METALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
POLLUTION
SORPTION
UPTAKE
540320* - Environment
Aquatic- Chemicals Monitoring & Transport- (1990-)
560300 - Chemicals Metabolism & Toxicology