Sentinel organisms

In addition to its broad occurrence under contrasting conditions, easy collection, relatively long life span, and resistance to the accumulation of toxic chemicals, zebra mussels provide a link between the pelagic and benthic food webs, possibly creating a rapid pathway for contaminant transfer from sediments to predators such as common carp (Cyprinus carpio) and, occasionally, humans [32, 42—4-7]. Consequently, zebra mussel has been considered a potential sentinel organism for assessing Hg redistribution from point sources in the Ebro River and the degree of bioavailability to river and wetland food webs. 

The use of terrestrial invertebrates as sentinel organisms has been suggested for monitoring lead. The spider Araneus umbricatus, for example, contained lead body burdens that correlated with that in a lichen (Lecanora conizaeoides) that is used to monitor atmospheric lead (Clausen 1984). Similarly, the woodlouse (Porcellio scaber) seems to reflect lead concentrations in adjacent soil or leaf litter (Hopkin et al. 1986). 

It is probable that these species are not representative of unusually sensitive or endangered species, but they can be considered appropriate sentinel organisms for many species of free-living wildlife. 

Coastal water, sediment, and sentinel organism (i.e., mussel-watch program) PCDDs/DFs, coPCBs, PCBs, OCPs, PAHs etc. 1999- MOMAFe Kim et al., 2002b Oh et al., 2003 Hong et al., 2006... 

Endpoint Selection As with other medical products, preclinical development can be conducted using selected toxicological endpoints (e.g., in-life, serum chemistry, hematological, urinalysis, and target and sentinel organ his-... 

Albalat, A., Potrykus, J., Pempkowiak, J., Porte, C. Assessment of organotin pollution along the Polish coast (Baltic Sea) by using mussels and fish as sentinel organisms. Chemosphere 47, 165-171 (2002)... 

Natural organisms can provide information pertaining to the chemical state within an environment, not through their presence or absence, but through their ability to concentrate heavy metals within tissues. For example, sentinel organisms, which include bivalves, have been used to monitor the concentrations of bioavailable metals and toxicity in aquatic ecosystems (Lau et al., 1998 Hall et al., 2002 Byrne and O Halloran, 2001). Bivalves have been used to monitor heavy-metal pollutants from gold-mine operations in Sarawak Malaysia (Lau et al., 1998). 

Define and discuss sentinel organisms as ecosystem monitors. What are advantages of using this method ... 

Morcillo, Y., Borghi, V., and Porte, C. 1997. Survey of organotin compounds in the western Mediterranean using molluscs and fish as sentinel organisms. Arch. Environ. Contam.Toxicol., 32, 198-203. 

The popularity of bivalve molluscs such as oysters and mussels as sentinel organisms for passive and active samphng of contaminants in waterbodies relates to the good match of these organisms with the above criteria. These and other organisms which are immobile or unlikely to venture far from the point of sampling are the most commonly used organisms. A wide variety of plants and animals have been used in this manner to sample contaminants in the environment (for examples and techniques see Ref. 20-24). 

Fish are considered as sentinel organisms in the aquatic ecosystem to assess the environmental contamination of water by several compounds. Fish can be chronically exposed to different pollutants and can bioaccumulate by direct exposure or through the food chain. 

Among sensitive species of terrestrial invertebrates, earthworms show disrupted enzyme activities at whole body concentrations as low as 28.5 mg Cu/kg DW. Soil copper concentrations between 53.0 and 100.0 mg/kg DW kill soil nematodes and soil faunal communities and cause a reduction in cocoon production of earthworms. Diets that contain between 50.0 and 63.0 mg Cu/kg ration inhibit development and reproduction in gypsy moths and oribatid mites. The wood louse (Porcellio scaber), an isopod, is proposed as a bioindicator of copper contamination in terrestrial ecosystems because whole body concentrations seem to reflect copper loadings in the isopod s immediate environment. More research is recommended on isopods and other sentinel organisms. 

Burns KA (1976) Hydrocarbon metabolism in the intertidal fiddler crab Ucapugnax. Mar Biol 36 5-11 Burns KA, Smith JL (1981) Biological monitoring of ambient water quality the case for using bivalves as sentinel organisms for monitoring petroleum pollution in coastal waters. Estuar Coast Shelf Sci 13 433-443... 

---