The paper, “Classification of marine microdebris: A review and case study on fish from the Great Barrier Reef, Australia” was published in Scientific Reports by researchers from the Australian Institute of Marine Science.
The paper reveals the diverse and prevalent nature of ingested debris in coral trout from the Great Barrier Reef (GBR) World Heritage Area. Marine debris, including small amounts of microplastics, was found in 95% of the fish collected. CEO of Seafood Industry Australia (SIA), Jane Lovell, responded by saying that “this research is a cause for concern, but ultimately more research needs to be done.”
In the paper, the marine debris ingested by 20 coral trout were examined using methods such as Fourier-Transform Infrared Spectroscopy. The debris was classified into three categories: synthetic, semi-synthetic and naturally-derived.
Synthetics include all microplastics, such as nylon, polyethylene, polypropylene, polystyrene, polyester and polyurethane. Semi-synthetic materials are manufactured synthetically from one or more substances of natural origin (e.g. rayon derived from cellulose) or a composite of both naturally-derived and synthetic materials. Naturally-derived materials include natural fibres derived from plants or animals.
Marine debris was found in 19 of the 20 trout analysed, with a total of 172 individual items collected from the fish. Of these items, 52% were classified as semi-synthetic, 42% as naturally-derived, and 6% as synthetic. These results correlate well with other literature on ingested microdebris in fish. Studies revealed a prevalence of semi-synthetic and naturally-derived fibres, which are often incorrectly reported as microplastics.
The authors point out that in GBR offshore waters, both land-based sources as well as oceanic and shipping sources have been suggested as potential sources for the marine plastic pollution.
The source of textile fibres detected in juvenile coral trout, however, is currently unclear and could be from domestic, land-based and shipping-based sewage discharges. Alternatively, international, unknown sources that deliver fibres to the GBR area through oceanic or atmospheric transport could be the cause.
Ms Lovell says the report “needs to be seen as a call to the community to be really conscious of the amount of plastics they are consuming, how they are consuming it and most importantly how they are disposing of it.”
“People need to take responsibility for their own consumption of plastics and take the steps to make changes, irrespective of plastic-bans and legislative enforcements. Just like the broader community, Australia’s professional fishers care about the health of Australia’s oceans and environment, and we encourage others to do the same.”
The authors note that effects of the ingestion of marine debris on wild fish populations are currently unknown and require further investigation. “We’d like to see more research done looking at what the long-term effect, if any, of ingesting plastics is on spawning and fish mortality,” says Ms Lovell.
The debris was found in the gut of the fish, which is removed prior to human consumption.
– Larissa Fedunik