Irate commercial fishermen and shop owners have joined forces to sue the Queensland government for more than $20 million.
The group of about 60 people are seeking compensation for businesses losses associated with a fish disease outbreak in Gladstone Harbour.
They are claiming the $70 billion port development at Gladstone Harbour contributed to the outbreak and impacted on their livelihoods.
Gladstone Harbour is being developed to make way for massive liquefied natural gas and coal seam gas projects.
Shine Lawyers partner Rebecca Jancauskas says Gladstone Ports Corporation has failed to comply with conditions set by the state government to compensate affected businesses.
Ms Jancauskas said she will lodge legal proceedings on Monday morning against the state government.
"We are asking the courts to order financial compensation for these impacted businesses," Ms Jancauskas told ABC Radio.
She said some fishing businesses had been forced to close.
"We have retail seafood outlets that have no fish that they can sell; the safe food regulations prohibit fishermen and retailers from selling fish they believe may be diseased," Ms Jancauskas said.
"That could result in criminal prosecution.
"We have got fishing vessels that are lying idle and there are concerns, given the length of this dredging project on a scale we have never yet seen in this state, these businesses will never be viable again."
Fishing was banned for three weeks in Gladstone Harbour last year, when barramundi and other fish turned up with cloudy eyes and discolouration.
Most fishermen blame a large-scale dredging operation but the government says last summer's floods caused the problems.
-AAP