Thesis
Influence of climate change on the fish fauna of the Swan-Canning and Peel-Harvey estuaries
Masters by Research, Murdoch University
2024
Abstract
South-western Australia is a climate change hotspot, with marked declines in rainfall leading to marinization of estuaries. This study on the extensively sampled Swan-Canning and Peel-Harvey estuaries used multiple sources of historical and contemporary data to investigate how the fish fauna had changed over time. A systematic literature review yielded records of 224 fish species, with 209 and 134 in the Swan-Canning and Peel-Harvey, respectively. The far larger number of species in the former estuary is likely due to its deeper waters and the greater vertical structure present within the lower reaches. Compared to previous species lists, the number of recorded species in the Swan-Canning Estuary increased from 110 (1979) to 135 (1987) to 209 (current study). Sixty of the 74 newly recorded species were marine stragglers and another four were non-native. Data on the fish community in shallow and deeper water from the Peel-Harvey Estuary in 2023 were compared to studies conducted in the 1990s and 2000s. Species accumulation curves demonstrated that overall species richness for the shallow waters of the Peel-Harvey Estuary had increased markedly mainly driven by the marine straggler species and underwent a shift in community composition. Although in the deeper waters there was no increase in the number of marine stragglers, the abundance of several marine estuarine-opportunist species increased. Monthly sampling using gill and seine nets was conducted in the lower Swan-Canning Estuary in 2022/23, which showed a reduction in the species richness and diversity during the winter months. Preliminary BRUV sampling throughout the entrance channel of the estuary provided insight into the presence of marine species not recorded by the gill or seine nets. From these multiple lines of evidence, it is clear that the species present in the Swan-Canning and Peel-Harvey estuaries are influenced by declining freshwater flow and marinization.
Details
- Title
- Influence of climate change on the fish fauna of the Swan-Canning and Peel-Harvey estuaries
- Authors/Creators
- Annika E Weibel
- Contributors
- James Tweedley (Supervisor) - Murdoch University, Centre for Sustainable Aquatic EcosystemsEssie Rogers (Supervisor)
- Awarding Institution
- Murdoch University; Masters by Research
- Identifiers
- 991005687462107891
- Murdoch Affiliation
- Centre for Sustainable Aquatic Ecosystems; School of Environmental and Conservation Sciences
- Resource Type
- Thesis
- Note
- Accelerated Research Masters with Training
Metrics
133 File views/ downloads
169 Record Views