A team of international researchers from countries including France, the Netherlands and the United States say the amount of mercury entering the ocean due to man-made activities has risen by as much as 150 per cent.
Their findings suggest that levels of mercury, a toxic trace metal that accumulates in aquatic organisms, have more than tripled in surface waters and increased by 150 per cent overall in the upper layers of the ocean.
Dr Erik van Sebille an Oceanographer from the University of NSW, says mercury is highly toxic, but small amounts which naturally occur in the ocean don't pose a problem.
It's the rapid rise that has occurred with industrialisation which he says is cause for concern.
"There has been ways that these organisms have been able to adapt to tiny amounts of mercury, that are naturally occurring in seawater. The problem is that with the rapid rise of mercury, because of the burning of coal, all of these organisms that live near the surface of the ocean, they are certainly experiencing much higher concentrations of mercury."
The researchers measured mercury levels during several recent trips to the Atlantic, Pacific, Southern and Arctic oceans.
The information gained will increase scientific understanding of how inorganic mercury is converted into toxic methyl mercury and incorporated into marine food webs.
Dr Erik van Sebille says what the scientists have done is look at how mercury moves around the ocean.
"Because the ocean circulation is almost a three dimensional, almost a roller-coaster ride where water sinks in some regions and goes back to the surface in some regions, it takes the mercury with it."
"By looking all over the ocean where they find high amounts of mercury and where they find low amounts of mercury, they've been able to map out how this three dimensional circle works."
SBS reporter Peggy Giakoumelos speaks with Dr Erik van Sebille.
Dr Erik van Sebille says it's really hard to tell exactly how this research may affect the current guidelines about the human consumption of fish.
He says consumers of fish would be best to follow guidelines set by the World Health Organisation about safe consumption levels.
"In limited amounts people are able to cope with it and they have been ever since the dawn of the first organisms two billions years ago. It's really the World Health Organisation and medical scientists that really have to now think about what is safe and what is not. But I am sure that there are very good monitoring programs in place. "
