As fishers gear up for the upcoming marron season in Western Australia, some experts say more investment is needed or parts of the fishery could be closed-off to the public.

Key points: Marron stocks are declining steadily in WA's fisheries

Marron stocks are declining steadily in WA's fisheries Fishers say much more could be done to protect the marron

Fishers say much more could be done to protect the marron There are no plans to close fisheries, but it could be a future option

While marron catch numbers have been stable over the past couple of years, annual reports from the WA Department of Primary Industries and Regional Development show a steady decline in recreational marron catch — from almost 103,000 in 2010 to 52,699 in 2017.

Since the sixties, the Department said it had restricted marron catch from about 100 tonnes a year to fewer than 10 tonnes.

About 7,000 baby marron are set to be released into Harvey dam, north of Bunbury. ( ABC South West: Jacqueline Lynch )

The decline in stock is thought to be largely due to environmental factors and a drying climate.

It prompted a research project, largely funded by the Commonwealth, that looked at the future of WA's marron fishery.

As part of the project 7,000 Pemberton-bred baby marron are being released into Harvey dam, north of Bunbury, ahead of the month-long marron season starting on January 8.

While they won't be big enough to be caught this year, head researcher Andrew Matthews said the project would help maintain stock into the future.

"We're basically looking at improving the amenity, so more people go," Mr Matthews said.

More should be done

But Mr Matthews, who works as a flora and fauna consultant, said the State Government needed to do more to ensure the sustainability of the marron fishery into the future.

"There are going to be fewer and fewer places for people to go and I think you'll find that eventually it will be reduced to an irrigation dam only fishery," he said.

He said this would mean the closure of some popular marron hotspots, in particular rivers.

Lead researcher Andrew Matthews says more needs to be done to protect marron stock. ( ABC South West: Jacqueline Lynch )

Mr Matthews is calling on the State Government to invest more money into monitoring and stocking the WA marron fishery.

"I think a couple of hundred thousand would go a long way in starting up a breeding program," he said.

"There will need to be some investment in maintaining the sustainability of the fisheries going forward."

WA's peak body for recreational fishers said while there were not serious concerns about stock numbers, more could be done to protect the South West marron population.

Recfishwest Fishing Development officer Matthew Gillett said there was always a risk of some parts of the fishery being shut.

But he said investment would stop this happening.

"Into the future, due to things like climate change, we may have to manage marron differently which will include projects such as stocking — like we're doing here in Harvey.

"We do have capability to go even bigger and better."

State to consider all measures to protect fishery

WA's Department of Primary Industries and Regional Development, which manages the fisheries, said while there are no plans to close off any of the fisheries, anything is on the table when it comes to ensuring the sustainability of marron stocks in the future.

The State says it will consider measures such as a larger breeding program to protect the fishery. ( ABC South West: Jacqueline Lynch )

Director of Aquatic Resource Management Nathan Harrison said WA was already investing a significant amount into the fishery.

"Maintaining marron stocks in the South West and having a viable, sustainable fishery is certainly a priority for the department," he said.

But he said the Department regularly looked at fresh ways to protect the fishery.

"We will consider the appropriateness of re-stocking as a strategy, we'll look at what has actually happened as part of this trial and certainly through that grants program there is the opportunity to consider the appropriateness of extending and potentially expanding that program if necessary."

Recommendations from the trial about future management of the fishery are expected to be released later this year.