Thesis
The impact of plastic pollution on detrital dynamics in current and future climates
Southern Cross University
Doctor of Philosophy (PhD), Southern Cross University
2024
DOI:
https://doi.org/10.25918/thesis.406
Appears in Recent Southern Cross PhD Theses
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Abstract
The world’s oceans are increasingly polluted with plastic waste, which impacts marine ecosystems and detrital dynamics. This thesis used mesocosms to investigate how various plastics affect the decomposition of marine macrophytes: Sargassum vestitum, Ecklonia radiata, and Zostera muelleri. Chapter 2 examined the effects of common consumer plastics on Sargassum vestitum. Results indicated that plastics generally slowed decomposition and nutrient release, with variations depending on the type of plastic. Chapter 3 assessed the impact of lost fishing gear, finding that recreational fishing lures had a less pronounced effect on the decomposition of Ecklonia radiata compared to commercial-grade fish netting. Chapter 4 investigated the influence of single-use and reusable masks, which increased pollution during the COVID-19 pandemic, on Zostera muelleri. It was found that disposable masks significantly accelerated eelgrass decomposition, while reusable masks had minimal impact. The study also considered the roles of ocean warming and acidification. Ocean warming consistently enhanced decomposition rates and nutrient release across all macrophytes, whereas ocean acidification had little effect. Chapter 5 included a field experiment with low-density polyethylene, confirming that plastics slowed the decomposition of kelp (Ecklonia radiata) but not seagrass (Zostera muelleri). In conclusion, plastics generally hinder marine macrophyte decomposition, with the extent of impact varying by plastic type and macrophyte species. Ocean warming accelerates decomposition and nutrient cycling, while acidification has limited influence. These findings highlight the complex interactions between plastic pollution and environmental stressors, with implications for coastal detrital dynamics, productivity, nutrient cycling, and blue carbon sequestration.
Details
- Title
- The impact of plastic pollution on detrital dynamics in current and future climates
- Creators
- Sebastian G. Litchfield
- Contributors
- Brendan Kelaher (Supervisor) - Southern Cross UniversityKai G Schulz (Supervisor) - Southern Cross University
- Awarding Institution
- Southern Cross University; Doctor of Philosophy (PhD)
- Theses
- Doctor of Philosophy (PhD), Southern Cross University
- Publisher
- Southern Cross University
- Number of pages
- xvii, 127
- Identifiers
- 991013221312502368
- Copyright
- © Sebastian G. Litchfield 2024
- Academic Unit
- Faculty of Science and Engineering; National Marine Science Centre
- Resource Type
- Thesis