Fishermen have been ordered not to scare off birds eating their mussels.
Fishermen say eider ducks are a threat to the mussel fishery
A government inspector has backed a decision by English Nature banning electronic wailers used to stop eider ducks from eating the young shellfish.
English Nature said the noise could disturb ducks and other waterfowl in the mussel beds bordering Lincolnshire and Norfolk.
Fourteen fishermen had applied for permission to use 22 scarers at the site, but the request was denied.
They said huge flocks of ducks were eating up the area's mussel stocks.
A public inquiry held in June at Boston Borough Council rejected an appeal by the fishermen under the Wildlife and Countryside Act.
It concluded the bird scarers were of "only limited effectiveness".
Ken Bagley of the Wash Fishermans' Association said the decision would mean the end of mussel industry in the area.
"We are fed up with buying mussel seed (baby mussels) and having the ducks eat them all," he said.
He said the mussel industry in the area was being "sold down the river" by the government and English Nature.
"They don't want us to catch fish and they don't want us to catch mussels."
The ducks can consume up to 2.5kg each time they visit the mussel beds.
English Nature said surveys have shown 3,000 birds use the mussel beds.
The Wash is the most important wetland in the UK for waterbirds supporting an average population of more than 400,000 over winter.
Sarah Dawkins, the species policy officer at the RSPB, commented: "The Wash is incredibly important for water birds, as it is for industry, and this has been acknowledged by the Secretary of State.
She added: "We do not think shellfishing should stop, only that it should return to a sustainable level so that fishermen and wildlife can co-exist. The Wash is not suitable for industrial-level fishing. It is the UK's best water bird site and so it should stay."