Insights into the dynamic world of the marine prokaryotic Plastisphere
Date
2023
Authors
Silva, Lokugan Hewage Vinuri Yasara
Editors
Advisors
Gillanders, Bronwyn
Pérez, Vilma
Pérez, Vilma
Journal Title
Journal ISSN
Volume Title
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Thesis
Citation
Statement of Responsibility
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Abstract
Plastic pollution has resulted in various detrimental impacts worldwide, with some of it ending up in our oceans. Plastic that enters our oceans undergoes rapid colonisation by the marine microbial community. This diverse yet unique community found on marine plastic, has been documented across the world and is identified as the plastisphere. Though the plastisphere has raised concern regarding its ability to transport pathogens and antibiotic resistant genes in our oceans, its succession, trends and dynamics are not well understood. To narrow research gaps on plastisphere dynamics, I explore the effects of various factors on the plastisphere. The factors investigated in this thesis are: effects of plastic type, temporal and spatial effects and the influence of plastic size. First, I investigate the impact of plastic type on the plastisphere by exploring five types of plastic. Here, I find that the PVC plastisphere differs from four other plastic polymers during the first four weeks of colonisation. In a long term (12 months) exposure experiment, I investigate the temporal patterns of three polymers finding that the PVC community converges with the other polymers over time. This was followed by an in situ experiment conducted at seven locations along the coastline of Adelaide, South Australia. This investigates the spatial dynamics of the plastisphere at local scales. Here, a trend of higher diversity in locations with lower latitudes was observed, despite the study being conducted within a <33 km scale. I also observed greater abundance of nitrifiers in the estuarine locations indicating potentially elevated ammonia levels in the water. Finally, a comparison of the plastisphere between microplastic and macroplastic found that microplastic tended to have higher diversity and a different composition. This thesis concentrates on enhancing knowledge on the dynamics and trends of the marine plastisphere. It further unveils the extraordinary capability of the plastisphere to form across various environmental factors, that inherently makes it a novel ecological habitat in the oceans.
School/Discipline
School of Biological Sciences
Dissertation Note
Thesis (Ph.D.) -- University of Adelaide, School of Biological Sciences, 2024
Provenance
This electronic version is made publicly available by the University of Adelaide in accordance with its open access policy for student theses. Copyright in this thesis remains with the author. This thesis may incorporate third party material which has been used by the author pursuant to Fair Dealing exceptions. If you are the owner of any included third party copyright material you wish to be removed from this electronic version, please complete the take down form located at: http://www.adelaide.edu.au/legals