Responses of Jellyfish to Environmental Change
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Author(s)
Primary Supervisor
Pitt, Kylie
Other Supervisors
Carroll, Anthony
Year published
2016
Metadata
Show full item recordAbstract
Worldwide, marine ecosystems are being impacted by a suite of anthropogenic stressors. Jellyfish are distributed worldwide and often proliferate rapidly to form conspicuous and problematic blooms. Jellyfish are considered robust to a range of environmental stressors and, as a consequence, there is concern among researchers that changing environmental conditions could facilitate jellyfish populations. There is, however, a paucity of robust evidence to support these claims because few manipulative experiments have been done to establish causative mechanisms that may allow jellyfish to proliferate under environmental stress. ...
View more >Worldwide, marine ecosystems are being impacted by a suite of anthropogenic stressors. Jellyfish are distributed worldwide and often proliferate rapidly to form conspicuous and problematic blooms. Jellyfish are considered robust to a range of environmental stressors and, as a consequence, there is concern among researchers that changing environmental conditions could facilitate jellyfish populations. There is, however, a paucity of robust evidence to support these claims because few manipulative experiments have been done to establish causative mechanisms that may allow jellyfish to proliferate under environmental stress. The overall aim of this thesis was to use manipulative experiments to test hypotheses about the influence of local, regional and global scale stressors on jellyfish. To assess the potential interactive effects of environmental stressors that occur episodically and on a local scale, I investigated the potential interactive effects of reduced salinity and a photosystem II herbicide (atrazine) on symbiotic medusae of Cassiopea sp. during a simulated rainfall event (Chapter 2). Medusae exposed to reduced salinity and high concentrations of atrazine individually exhibited negative effects. Medusae survived and recovered from conditions that mimicked mild and moderate rainfall events, but exposure to conditions that mimicked a heavy rainfall event (i.e. reduced salinity and high concentrations of atrazine in combination) caused medusae to die. These findings suggest that although symbiotic medusae can tolerate mild and moderate rainfall events, medusae may not survive heavy rainfall events that typically expose biota to high levels of herbicide runoff and reduced salinity.
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View more >Worldwide, marine ecosystems are being impacted by a suite of anthropogenic stressors. Jellyfish are distributed worldwide and often proliferate rapidly to form conspicuous and problematic blooms. Jellyfish are considered robust to a range of environmental stressors and, as a consequence, there is concern among researchers that changing environmental conditions could facilitate jellyfish populations. There is, however, a paucity of robust evidence to support these claims because few manipulative experiments have been done to establish causative mechanisms that may allow jellyfish to proliferate under environmental stress. The overall aim of this thesis was to use manipulative experiments to test hypotheses about the influence of local, regional and global scale stressors on jellyfish. To assess the potential interactive effects of environmental stressors that occur episodically and on a local scale, I investigated the potential interactive effects of reduced salinity and a photosystem II herbicide (atrazine) on symbiotic medusae of Cassiopea sp. during a simulated rainfall event (Chapter 2). Medusae exposed to reduced salinity and high concentrations of atrazine individually exhibited negative effects. Medusae survived and recovered from conditions that mimicked mild and moderate rainfall events, but exposure to conditions that mimicked a heavy rainfall event (i.e. reduced salinity and high concentrations of atrazine in combination) caused medusae to die. These findings suggest that although symbiotic medusae can tolerate mild and moderate rainfall events, medusae may not survive heavy rainfall events that typically expose biota to high levels of herbicide runoff and reduced salinity.
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Thesis Type
Thesis (PhD Doctorate)
Degree Program
Doctor of Philosophy (PhD)
School
Griffith School of Environment
Copyright Statement
The author owns the copyright in this thesis, unless stated otherwise.
Item Access Status
Public
Subject
Jellyfish ecology
Jellyfish, Environmental conditions
Jellyfish, Environmental stressors