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The assimilation and elimination of cesium by freshwater invertebrates

dc.contributor.authorTostowaryk, Tracy M., author
dc.contributor.authorWhicker, F. Ward, advisor
dc.contributor.authorRowan, David, advisor
dc.contributor.authorClements, W. H. (William H.), committee member
dc.contributor.authorHinton, Tom, committee member
dc.date.accessioned2007-01-03T04:30:31Z
dc.date.available2007-01-03T04:30:31Z
dc.date.issued2000
dc.descriptionDepartment Head: Daniel E. Binkley.
dc.description.abstractFreshwater invertebrates are important vectors of radioactive cesium 134Cs and 137CS) in aquatic food webs, yet little is known about their cesium uptake and loss kinetics. This study provides a detailed investigation of cesium assimilation and elimination by freshwater invertebrates. Using five common freshwater invertebrates (Gammarus lacustris, Anisoptera sp. nymphs, Claassenia sabulosa and Megarcys signata nymphs, and Orconetes sp.), a variety of food types (oligochaete worms, mayfly nymphs and algae) and six temperature treatments (3.5 to 30°C), the following hypotheses were tested: 1) cesium elimination rates are a positive function of water temperature; 2) cesium elimination rates increase with decreasing body size; 3) assimilation efficiencies range between 0.6 and 0.8 for diet items low in clay. Cesium loss exhibited first order, non-linear kinetics, best described by a two component exponential model. Cesium assimilation efficiencies were higher for invertebrates fed oligochaetes (0.77) and algae (0.80) than those fed mayfly nymphs (0.20). Cesium elimination rate constants ranged from 0.002 to 0.125 d-1 across taxa and temperatures. Within each taxon, linear regressions of the natural logarithm of cesium elimination rate constants on temperature yielded positive, significant relationships. As temperature coefficients were not significantly different across taxa, the data were combined into a general model of cesium elimination by freshwater invertebrates as a function of temperature, body size and a categorical variable for thermal optima (warmwater and cool-water adapted taxa). Cesium elimination rate constants were found to increase with temperature, decrease with body size, and be much lower for warmwater adapted invertebrates than cool-water adapted invertebrates. Both the cesium assimilation efficiencies and general model of cesium elimination rate constants for freshwater invertebrates are in excellent agreement with those for fish. Quantification of cesium assimilation efficiencies and elimination rate constants for freshwater invertebrates allows, for the first time, development of dynamic aquatic food web models for .risk assessments, and it enables the in situ quantification of invertebrate feeding rates and other bioenergetic parameters.
dc.format.mediummasters theses
dc.identifier2000_Fall_Tostowary_Tracy.pdf
dc.identifierETDF2000100001ECOL
dc.identifier.urihttp://hdl.handle.net/10217/37344
dc.languageEnglish
dc.language.isoeng
dc.publisherColorado State University. Libraries
dc.relationCatalog record number (MMS ID): 991010545719703361
dc.relationQL365.365.T677 2000
dc.relation.ispartof2000-2019
dc.rightsCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.
dc.titleThe assimilation and elimination of cesium by freshwater invertebrates
dc.typeText
dcterms.rights.dplaThis Item is protected by copyright and/or related rights (https://rightsstatements.org/vocab/InC/1.0/). You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).
thesis.degree.disciplineEcology
thesis.degree.grantorColorado State University
thesis.degree.levelMasters
thesis.degree.nameMaster of Science (M.S.)

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