Environmental and biological characteristics of lagoons on the southwest coast of Ireland

dc.check.date10000-01-01
dc.check.embargoformatE-thesis on CORA onlyen
dc.check.entireThesisEntire Thesis Restricted
dc.check.infoIndefiniteen
dc.check.opt-outNot applicableen
dc.check.reasonThis thesis is due for publication or the author is actively seeking to publish this materialen
dc.contributor.advisorJansen, Marcel A.K.en
dc.contributor.advisorChapman, Deborahen
dc.contributor.authorLettice, Susan Noreen
dc.contributor.funderIrish Research Council for Science Engineering and Technologyen
dc.date.accessioned2015-08-17T12:26:23Z
dc.date.issued2014
dc.date.submitted2014
dc.description.abstractCoastal lagoons are defined as shallow coastal water bodies partially separated from the adjacent sea by a restrictive barrier. Coastal lagoons are protected under Annex I of the European Habitats Directive (92/43/EEC). Lagoons are also considered to be “transitional water bodies” and are therefore included in the “register of protected areas” under the Water Framework Directive (2000/60/EC). Consequently, EU member states are required to establish monitoring plans and to regularly report on lagoon condition and conservation status. Irish lagoons are considered relatively rare and unusual because of their North Atlantic, macrotidal location on high energy coastlines and have received little attention. This work aimed to assess the physicochemical and ecological status of three lagoons, Cuskinny, Farranamanagh and Toormore, on the southwest coast of Ireland. Baseline salinity, nutrient and biological conditions were determined in order to provide reference conditions to detect perturbations, and to inform future maintenance of ecosystem health. Accumulation of organic matter is an increasing pressure in coastal lagoon habitats worldwide, often compounding existing eutrophication problems. This research also aimed to investigate the in situ decomposition process in a lagoon habitat together with exploring the associated invertebrate assemblages. Re-classification of the lagoons, under the guidelines of the Venice system for the classifications of marine waters according to salinity, was completed by taking spatial and temporal changes in salinity regimes into consideration. Based on the results of this study, Cuskinny, Farranamanagh and Toormore lagoons are now classified as mesohaline (5 ppt – 18 ppt), oligohaline (0.5 ppt – 5 ppt) and polyhaline (18 ppt – 30 ppt), respectively. Varying vertical, longitudinal and transverse salinity patterns were observed in the three lagoons. Strong correlations between salinity and cumulative rainfall highlighted the important role of precipitation in controlling the lagoon environment. Maximum effect of precipitation on the salinity of the lagoon was observed between four and fourteen days later depending on catchment area geology, indicating the uniqueness of each lagoon system. Seasonal nutrient patterns were evident in the lagoons. Nutrient concentrations were found to be reflective of the catchment area and the magnitude of the freshwater inflow. Assessment based on the Redfield molar ratio indicated a trend towards phosphorus, rather than nitrogen, limitation in Irish lagoons. Investigation of the decomposition process in Cuskinny Lagoon revealed that greatest biomass loss occurred in the winter season. Lowest biomass loss occurred in spring, possibly due to the high density of invertebrates feeding on the thick microbial layer rather than the decomposing litter. It has been reported that the decomposition of plant biomass is highest in the preferential distribution area of the plant species; however, no similar trend was observed in this study with the most active zones of decomposition varying spatially throughout the seasons. Macroinvertebrate analysis revealed low species diversity but high abundance, indicating the dominance of a small number of species. Invertebrate assemblages within the lagoon varied significantly from communities in the adjacent freshwater or marine environments. Although carried out in coastal lagoons on the southwest coast of Ireland, it is envisaged that the overall findings of this study have relevance throughout the entire island of Ireland and possibly to many North Atlantic coastal lagoon ecosystems elsewhere.en
dc.description.statusNot peer revieweden
dc.description.versionAccepted Version
dc.format.mimetypeapplication/pdfen
dc.identifier.citationLettice, Susan N. 2014. Environmental and biological characteristics of lagoons on the southwest coast of Ireland. PhD Thesis, University College Cork.en
dc.identifier.urihttps://hdl.handle.net/10468/1915
dc.language.isoenen
dc.publisherUniversity College Corken
dc.rights© 2014, Susan N. Lettice.en
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/3.0/en
dc.subjectWater Framework Directiveen
dc.subjectHabitats Directiveen
dc.subjectIrish habitaten
dc.subjectCoastal lagoonen
dc.subjectCoastal habitaten
dc.subjectDecompositionen
dc.subjectMacroinvertebrate communityen
dc.subjectNutrientsen
dc.subjectSalinityen
dc.subjectChlorophyll aen
dc.subjectWater monitoringen
dc.subjectCoastal managementen
dc.subjectDiversityen
dc.subjectTidalen
dc.subjectClassificationen
dc.thesis.opt-outtrue
dc.titleEnvironmental and biological characteristics of lagoons on the southwest coast of Irelanden
dc.typeDoctoral thesisen
dc.type.qualificationlevelDoctoralen
dc.type.qualificationnamePhD (Science)en
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