A Newcastle-based ecologist has raised major concerns about a project that aims to clean up plastic in the Pacific Ocean.
The Great Pacific Garbage Patch is among the most alarming examples of plastic pollution in the world.
An organisation called The Ocean Cleanup is planning to remove this garbage in a $45 million project.
The work required to do so has been dubbed "the largest cleanup in history".
Dr Vincent Raoult, of the University of Newcastle, said it was simplistic to believe that "you can solve the problem by cleaning plastic in the ocean".
"It's a global issue that's very complicated to solve," said Dr Vincent Raoult, of the University of Newcastle.
The Ocean Cleanup has dubbed the patch "the largest accumulation zone of plastic in the world".
It was spread across an area "three times the size of France or twice the size of Texas".
Dutch inventor Boyan Slat, 25, founded the non-profit organisation at age 18, with a mission to "rid the world's oceans of plastic".
A spokeswoman for the Ocean Cleanup said: "We have done extensive scientific research into the nature of the plastic problem".
"Plastic pollution is a legacy problem: most of the plastic in the garbage patch has been there for decades and is very slowly disintegrating into smaller and smaller pieces."
Once they become microplastics [less than 10 millimetres], they would be "increasingly difficult" to remove from the water.
Research shows that most of the plastic that ends up in the ocean comes from 10 rivers - the Yangtze, Yellow, Hai, Pearl, Amur, Mekong, Indus and Ganges Delta in Asia and the Niger and Nile in Africa.
These rivers generally have high populations nearby - in some cases, hundreds of millions of people.
"Certainly there's a lot of plastic in the oceans and it's very widespread, but it's definitely worse in some areas than others," Dr Raoult said.
"Instead of going out and cleaning the oceans, it would make a lot more sense to prevent more plastic from getting into the oceans."
He said the affected rivers were in countries that "don't have appropriate waste-processing facilities".
"The only solution for people who live there is to dump stuff in the river."
They have no other options, he said.
"We're lucky in Western countries that we have waste services and you put your stuff in the bin and it disappears. But they don't have that luxury."
He said the money available for conservation was finite and the $45 million could be better spent.
The Ocean Cleanup spokeswoman said it was "imperative that the supply of plastics into the oceans" was stopped.
"That is why we are also doing extensive scientific research into river plastic pollution," she said.
However, she said more than 80,000 tonnes (the equivalent of 500 jumbo jets) of plastic was floating in the Pacific garbage patch.
This plastic, in an ocean area between California and Hawaii, would "break down over time, entering the food chain".
"This is a problem that needs solving. We never said it was easy but that is our mission."
Dr Raoult said the Ocean Cleanup was designed to catch floating plastic.
"But we know the vast majority of plastic ends up at the bottom of the ocean, or deeper down in the water column. So it's basically a band-aid," he said.
Another massive problem is the recycling industry.
A lot of Australia's plastic garbage ends up in south-east Asia. Some of this plastic goes to landfill and some is illegally burnt or dumped, polluting land, air and water in poorly-regulated countries, Greenpeace says.
Some may push the argument that the manufacture of plastic should be banned, but Dr Raoult said it was a "pretty unique substance".
"You think about how much plastic is involved in food preservation and your average hospital. You can make it sterile, it's waterproof and it lasts a while, which is important for storing things.
"By and large, the inside of your car is plastic. What are they going to make cars with?"
Some advocate for the use of reusable bags and cups to reduce plastic use.
The problem, he said, was the energy needed to make a reusable bag was much more than a cheap plastic bag.
"So unless you're using that bag thousands of times, it's not actually a net benefit to the environment.
"Eliminating plastic use would be fantastic, but unfortunately in our current society, there's not really a whole lot of alternatives."
