Year: 2011
Type: dissertation
Abstract: Coastal ecosystems, including estuaries, provide a range of services to humans, \nmediated by the species within these ecosystems. Microphytobenthos (MPB) play a \nvital role in many key processes within estuarine ecosystems, and provide a food \nsource for higher trophic levels. Anthropogenic activity is already causing changes to \necosystems, through pollution, overexploitation and, more recently, climate change. \nIncreasing temperature and carbon dioxide levels, and altered biodiversity, are likely \nto affect species, and their interactions, within these ecosystems. Much ecological \nresearch has focused on the effects of a single stressor on specific species or \necosystems, with relatively little work examining the effects of multiple stressors. \nThe research in this thesis investigates the effects of altered environmental variables \n(light, tidal regime, temperature and carbon dioxide) and different macrofaunal \ndiversity on primary production (MPB biomass) through a series of manipulative lab-based mesocosm experiments. This work also examines the temporal variability of \nenvironmental stressors on species across two trophic levels. Results demonstrate how \nmultiple environmental stressors interact in a complex and non-additive way to \ndetermine an ecosystem response (MPB biomass, nutrient concentration), and the \neffects of altered biodiversity were underpinned by strong species effects. Temporal \nvariation of stressors had a strong effect on ecosystem response. In marine coastal \necosystems, environmental changes through ocean acidification will have economic \nand social repercussions, directly impacting the human services and livelihoods that \nthese systems provide. As such, future research should be focused on identifying and \nmitigating the inevitable multiple effects that future global change may have on \ncoastal ecosystems.
Author: Natalie Hicks
Language: English
Subfield: Oceanography
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1592819674