Microplastics have been detected in wild-caught fish from the Great Barrier Reef World Heritage Area, researchers report.
A study conducted by the Australian Institute of Marine Science (AIMS) in Townsville is the first study to report the detection of man-made fibres in the intestines of coral trout, a commercially important reef fish, in the first sign marine debris is entering the animals’ food chain.
The research published in Nature found 115 items of waste in the gut of 19 juvenile coral trout caught at Lizard, Orpheus, Heron and One Tree Islands on the Great Barrier Reef.
AIMS marine ecologist Frederieke Kroon said the long-term effects of the pollution were unclear at this stage.
“In our study, the condition of the coral trout did not appear to be affected by the abundance of ingested microdebris,” she said.
Dr Kroon said the effect of the ingested plastics on spawning rates and viability of the fishery was unknown at this point.
“We do not know whether there could be any longer-term effects on coral trout reproduction or mortality.”
The quota for commercial fishing of coral trout was recently restored to pre-2014 levels, when an alarming decline in stocks led to a reduction in the total allowable catch figure by the Queensland Government.
The findings of the study will be used to improve knowledge of exactly what microplastic fibres are commonly ingested by fish, with evidence showing semi-synthetic fibres like rayon found more often than wholly artificial fibres like polyester.
Source of microplastics not known
The origin of the plastics has not been confirmed, meaning it could be land-based or from shipping traffic through the Great Barrier Reef.
The plastic-free movement has led to the removal of single-use items like cutlery from many coastal businesses in recent months, with Plastic Free Noosa claiming to have recently removed 1.4 million items from circulation in 2018 through a voluntary program to replace plastics with compostable material.
While the process has been welcomed by environmental groups, the Australian Marine Conservation Council (AMCS) wants legislation to enforce such change.
Great Barrier Reef campaign director Imogen Zethoven said the Federal Government should work to reduce the estimated 5 trillion pieces of plastic in the oceans.
“AMCS would like to see the Australian Government introduce a 70 per cent reduction of plastic pollution entering our waterways and reaching our oceans by 2020, commencing immediately with a ban on single-use plastics by 2023,” she said.
“[The research] is a great concern. More research needs to be done to examine the consequences of the pollution on human health and the long-term effects on the coral trout.”
Campaigns to move away from single use plastic are active in developed nations like Australia, with conservationists adamant reducing their use will assist in cutting plastic waste flowing to the coastline.
AMCS has also welcomed the expansion of 10 cent container recycling incentives, recently rolled out in New South Wales and Queensland.
“We expect the rate of recycling of these containers to increase up to 50 per cent, reaching similar rates like in South Australia where the return rate is over 80 per cent,” Ms Zethoven said.
Seafood Industry Australia has been contacted for comment.