Plans to classify the River Severn as coastline could see council taxpayers in Somerset and Gloucestershire paying thousands to help fishing communities.
The Devon and Severn Inshore Fisheries and Conservation Authority (IFCA), which manages the exploitation of sea fisheries, is being reorganised.
It now says part of the Bristol Channel and Severn Estuary is designated as "seashore" so should be included.
Both North Somerset and Gloucestershire County Council will oppose the move.
'Tooth and nail'
The IFCA will use the money to make sure inshore fisheries are properly looked after, protecting the marine environment and ensuring fishing is done in a sustainable way.
But the deputy leader of North Somerset Council, Elfan Ap Rees, said it was unclear how many jobs they would be funding, what the salaries would be, how many vessels would be used and what their running costs would be.
He said he would be fighting "tooth and nail" to stop the authority from having to fund it.
He said: "We have no objection to Devon wanting to continue to manage its sea fishery resources or the wider principle, but are totally opposed to being part of this quango which will have no benefit to North Somerset.
"As a council we are having to look at ways we can save up to £42m over the next four years and I suggest that supporting Devon's fishing industry is very low on the agenda.
"IFCA needs to cast its net elsewhere for the funding it says is needed and not expect our council taxpayers to stump up the cash," he added.
'Absolutely no benefit'
Councillor Stan Waddington, from Gloucestershire County Council, said the council was "very annoyed" at the proposals - especially at a time when the council was having to make cuts resulting in one in six of its workforce losing their jobs.
He said the council had been imposed with a bill for £130,000 "for something the county will get absolutely no benefit" from as "we have no sea fishing here".
The Devon IFCA has been in existence for more than a century to manage the exploitation of sea fishery resources off the Devon coast but is being reorganised to include the Bristol Channel and Severn estuary.
This means local authorities including North Somerset, Bristol, South Gloucestershire and Gloucestershire will now have to pay a levy. towards the IFCA.