THE ROLE OF ROAD SALT DEICER AND RESOURCE BIODIVERSITY ON AQUATIC CONSUMER FEEDING DYNAMICS

dc.contributor.advisorSwan, Christopher
dc.contributor.authorMcDonald, Lauren N
dc.contributor.departmentGeography and Environmental Systems
dc.contributor.programGeography and Environmental Systems
dc.date.accessioned2022-09-29T15:38:01Z
dc.date.available2022-09-29T15:38:01Z
dc.date.issued2021-01-01
dc.description.abstractRoad salt deicer is a growing pollutant of concern in the United States as urbanizationand human expansion continues at a rapid rate. Deicer infiltrates surface waters through stormwater runoff and increases chloride concentrations in freshwater ecosystems. The purpose of this study was to evaluate the effects of road deicer on a critical function of freshwater ecosystems - leaf litter breakdown. I hypothesized that increased chloride concentrations would decrease breakdown rates through decreased invertebrate consumer activity. To examine the impacts of chloride breakdown rates, a multi-factorial laboratory experiment was designed to test the effect of chloride on aquatic consumer feeding rates and examine the role of heterogeneous leaf litter under these conditions. Leaf litter and aquatic invertebrates (Gammarus sp.) were collected from headwater streams in Maryland (USA). Microcosms were inoculated with stream water and subjected to a chloride treatment (0 or 600mg/L), a leaf litter treatment (F. grandifolia, A. rubrum, or "mixed”), and an invertebrate treatment (presence or absence). After 28 days, mass loss rate was calculated for all treatments. In the single-species litter treatments, mass loss increased under the presence of chloride in both the presence and absence of the invertebrate consumer. Regardless of invertebrate presence, chloride only decreased mass loss in the mixed leaf litter assemblages. Further, the results showed a diversity effect between the single and mixed-species litter treatments but only in the invertebrate absent treatments. Therefore, the presence of an invertebrate eliminated the diversity effect regardless of chloride concentration. In short, increased chloride concentrations altered feeding rates though differently than predicted while a diversity effect was observed only in the absence of the invertebrate. The results suggest a complex interaction between chloride, heterogeneous leaf litter, and aquatic consumers that requires additional research to further understand the relationship between these factors.
dc.formatapplication:pdf
dc.genretheses
dc.identifierdoi:10.13016/m2hsnr-cnbd
dc.identifier.other12475
dc.identifier.urihttp://hdl.handle.net/11603/25995
dc.languageen
dc.relation.isAvailableAtThe University of Maryland, Baltimore County (UMBC)
dc.relation.ispartofUMBC Geography and Environmental Systems Department Collection
dc.relation.ispartofUMBC Theses and Dissertations Collection
dc.relation.ispartofUMBC Graduate School Collection
dc.relation.ispartofUMBC Student Collection
dc.rightsThis item may be protected under Title 17 of the U.S. Copyright Law. It is made available by UMBC for non-commercial research and education. For permission to publish or reproduce, please see http://aok.lib.umbc.edu/specoll/repro.php or contact Special Collections at speccoll(at)umbc.edu
dc.sourceOriginal File Name: McDonald_umbc_0434M_12475.pdf
dc.subjectChloride
dc.subjectFreshwater streams
dc.subjectInvertebrate consumers
dc.subjectLeaf litter breakdown
dc.subjectRoad deicer
dc.titleTHE ROLE OF ROAD SALT DEICER AND RESOURCE BIODIVERSITY ON AQUATIC CONSUMER FEEDING DYNAMICS
dc.typeText
dcterms.accessRightsDistribution Rights granted to UMBC by the author.
dcterms.accessRightsAccess limited to the UMBC community. Item may possibly be obtained via Interlibrary Loan thorugh a local library, pending author/copyright holder's permission.

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