Marlborough Sounds residents and recreational fishers warn that scallops could disappear from the area unless tougher constraints are placed on commercial dredgers.
The Kenepuru and Central Sounds Residents' Association, Pelorus Boating Club and the Marlborough Recreational Fishers Association said the current management system for scallops was not working.
They warned that unless urgent steps were taken the scallop resource would not recover.
The Residents' Association vice president, Andrew Caddie, said the commercial scallop industry wanted to harvest 34 tonnes this year and the figures showed that that was not sustainable.
He said Ministry for Primary Industries (MPI) stock assessment data recorded a serious decline in the scallop resource from overfishing by commercial operators. The catch has gradually dropped from more than 100 tonnes in 2009 to just 22 tonnes last year.
Mr Caddie said if it kept going on its current path the industry would soon be finished.
"I'd say a maximum two years but that's optimistic. If the industry persists in pushing for the 34 tonnes it's seeking this year, it will be the end of commercial dredging."
Mr Caddie said dredging was an invasive form of fishing. Although the recreational sector also had to take some responsibility, he sympathised with those who had to "take some pain" for a situation largely imposed by the commercial sector.
"I tend to agree we have to look at practices, because we want to save the resource, but that can only happen by putting in place a more sustainable regime."
The Marlborough Sounds scallop fishery is managed by the Challenger Scallop Enhancement Company under a Memorandum of Understanding with MPI.
In May each year, Challenger commissions the National Institute of Water and Atmospheric Research (NIWA) to carry out a scallop biomass survey. A harvest plan is proposed based on the survey report, and is then passed on to MPI.
The Minister reviews the harvest plan in consultation with MPI, and commercial dredging begins around late August.
Mr Caddie said this year's survey results revealed the biomass was at an "all time low".
Challenger declined to comment, but a spokesperson for Primary Industries Minister Nathan Guy said the fishery's sustainability would be the main consideration in an assessment of the commercial dredger's harvest plan.
"Having received the scallop harvest plan, the Minister has asked MPI officials to review it and provide advice to him, which it will do in due course."