IT is arguably one of Australia's most stunning coastal locations and the beating heart of the nation's seafood industry.
But fishermen and environmental experts are warning Port Lincoln's harbour could be transformed into a toxic "red tide" of algae that will choke fish and could put human health at risk if plans to ship iron ore from the port go ahead.
Within weeks, Port Lincoln will learn if it will become the next embarkation point for iron ore destined for the Chinese market, raising fears of an ecological and public relations disaster for the city's "clean and green" image.
Planning Minister Paul Holloway is expected to approve plans later this month by Centrex Metals to upgrade the Port Lincoln wharf to handle exports of up to 2 million tonnes of ore each year for the next seven years.
The Australian Southern Bluefin Tuna Industry Association opposes the plan, saying it would be a disaster for the $300- million-a-year local fishing industry.
Centrex has hit back, saying there has never been a toxic algal bloom in Port Lincoln and has accused the fishing industry of "misrepresenting the facts" and of "scaremongering".
The tuna association commissioned CSIRO research which found that even a minute amount of iron in local waters could cause toxic phytoplankton blooms, contaminating and killing fish and potentially harming humans.
Association research manager David Ellis told the Sunday Mail there were types of algae which, if they took up iron, could release toxins that kill fish.
"And some shellfish like mussels take this up so when you eat them you end up with paralytic shellfish poisoning, amnesia or diarrhoeic poisoning," he said.
The concern has been shared by the state's Environment Protection Authority which has recommended rejecting Centrex Metal's plans, on health grounds, to the Development Assessment Commission which in turn recommends to the minister either approval or refusal.
The EPA warned that adding additional iron to Boston Bay could act as a nutrient for phytoplankton bloom growth
In May, Mr Holloway granted Centrex Metals a 10-year lease to mine iron ore at Wilgerup, near Lock. The mine is expected to turn over $70 million a year, with 135 people employed at the mine site and 10 at the port.
In an emailed response to the Sunday Mail, Centrex managing director Gerard Anderson accused the tuna association of "selectively interpreting" the CSIRO data to "give the impression" that algal blooms would occur.
He said a large amount of iron was being poured into the harbour already through fishing and urban run-off without any impact on the marine environment.
Barry Stott, tug master at Port Lincoln Tugs, supported Centrex's plan, saying his workload had fallen sharply because of a downturn in the amount of grain being exported through Port Lincoln.
"Providing they (Centrex) do the world's best practice I can't see a problem with it," he said. The fishing industry's environmental concerns were "a fallacy", he said.
