Plastics in the environment
In May of 2021, five members of the Gillanders Aquatic Ecology Lab were lucky enough to receive an Association of Commonwealth Universities Blue Charter Knowledge Exchange Grant. The aim of the grant was to produce a knowledge exchange tool to better engage key stakeholders in research.
Completing the Blue Charter Knowledge Exchange Training Programme was the first step for Nina Wootton, Vinuri Silva, Nikita Pring, Solomon Ogunola and Sophie Dolling to help guide their research outputs to the public and start a conversation, benefiting the community and the environment. Public knowledge and perception of plastic pollution and its impacts are relatively poor, so it was decided that a video highlighting the various areas of plastic pollution research occurring in the Gillanders Aquatic Ecology Lab would be an excellent educational outreach tool to promote and boost knowledge exchange. Only by communicating the presence and impacts of plastic pollution in our marine environments will we be able to create change.
To find out more about each of our researcher’s projects and their progress we provide a brief summary below.
Fishing for solutions (Nina Wootton, @nina__marina)
Nina’s PhD research focused on the extent and type of plastic in seafood, particularly fish. After gathering all the current global literature investigating microplastic in fish, she discovered that the Oceanic region was vastly understudied compared to other world-wide locations. Consequently, she sampled over 1000 fish from Australia and Fiji to find 38% had ingested microplastic. Recognising that this may have negative impacts on the seafood industry she spoke to fishers and fishmongers to create some supported management strategies to lower plastic use and impact within the seafood industry. Positively, she found a real willingness to incorporate plastic-free alternatives into seafood and fishing businesses, and she hopes to further educate and collaborate with fishers in this space in the coming year. All of the papers from Nina’s PhD are now published, with links to the publication available under the ‘publications’ and ‘publications 2021’ tabs of the Gillanders Lab page website.
Image: Thirty eight percent of fish from Fiji and Australia were found to have ingested plastic.
Contaminated crustaceans? (Solomon Ogunola)
Solomon’s PhD research focuses on microplastics in Australian prawns and crabs, sampled from fish markets across Australia. These benthic species were chosen because they play key ecological roles but are also an important fishery and loved by consumers across Australia. King, banana and tiger prawns as well as blue-swimmer and mud crabs were collected from five states (Western Australia, South Australia, New South Wales, Queensland and Northern Territory) and analysed. Additionally, Solomon is comparing microplastics in crustaceans collected in the wild and aquaculture in Australia and abroad. He will also investigate if biomagnification of microplastics across food webs (i.e., if microplastics can accumulate and be transferred from lower to higher trophic organisms in the marine food webs) is occurring. Lastly, Solomon will investigate if bivalve molluscs reflect the abundance and characteristics of microplastics present in the South Australian coastal waters and if they can be used to monitor microplastic contamination.
Image: Right - Solomon in the field. Below - Prawns and crabs from Australian fish markets were sampled and analysed for plastics.
Hidden in the mangroves (Nikita Pring)
Nikita’s PhD focuses on marine debris and microplastics in coastal habitats. Plastics are a major component of marine debris in our coastal habitats and may affect plants and animals in a multitude of ways. Nikita’s research investigates how mangrove forests and seagrass meadows trap plastics through their branches, leaves and sediment. The roots of mangroves and seagrasses filter the water and trap sediment and nutrients within, and due to the structure of a mangrove tree with its twisting branches and roots that sit above ground, they are likely to be natural traps for plastic contamination. Food wrappers, plastic bags and fishing nets are likely trapped through the branches, whereas microplastics are within the sediment.
The final part of Nikita’s research is about the characteristics of sediment and microplastic. The sediment in our coastal habitats vary in size, type and characteristics; some are so fine they’re soft to walk on, and some are rocky. Does this have an impact on the accumulation of microplastic in certain coastal habitats? Stay tuned to find out more!
Life on the plastisphere (Vinuri Silva, @SilvaVinuri)
The “Plastisphere” is the community that marine microbes such as bacteria form on plastics. Despite the uniqueness of this diverse community, it is understudied in Australia. Vinuri’s PhD focuses on identifying the types of bacteria that comprise the plastisphere in our waters. Certain types of bacteria may breakdown plastic, and Vinuri is on the lookout to discover if such bacteria exist in our waters. Finding a plastic-degrading bacteria that naturally exists in our oceans could lead to a natural solution to the ever-growing plastic pollution problem.
However not all documented plastisphere bacteria are “good”. Some pathogenic bacteria such as the Vibrio bacteria, have been found to “hitch hike rides” on plastic debris in other parts of the world. Pathogens can cause diseases in seafood with the Vibrio bacteria being responsible for vibriosis – a prevalent fish disease. Vinuri’s work will also focus on identifying pathogenic bacteria that colonize the plastisphere in Australia.
Toxic transporters of the sea (Sophie Dolling, @sophdolling)
Plastic pollution is one of the greatest threats facing our marine environments and could be causing more harm than first thought. Plastics are known to adsorb ‘hydrophobic’ or ‘water-repellent’ chemicals from the water column. This can cause concentrations of chemical pollutants to be up to 5000x higher on the plastic surface than the surrounding water column. Many chemical pollutants are thought to act in this way, including plasticisers, pharmaceuticals, pesticides, PFAS (per and poly-fluoroalkyl substances) and endocrine disrupting agents.
If chemical pollutants are present in such high concentrations on plastic pollution, could they be carried into marine food webs? This is the question that Sophie aims to answer in her PhD. Sophie is currently using an analytical chemistry approach to identify a method to detect these chemical pollutants both on the surface of plastics as well as in the tissues of seafood species. Using this method, Sophie is analysing various plastic and tissue samples to try and uncover the link between plastics and chemical pollution ending up in our seafood.
Thank you to Dr Flynn Slattery, Dr Tullio Rossi and the team at Animate Your Science for their hard work on the video.
Near Calperun Station, SA
Giant Australian cuttlefish