Dozens of jobs are expected to be lost at a key port in Western Australia's south after a series of blows to the state's mining sector.

Expressions of interest for voluntary redundancies are being sought at Esperance Port where staff are awaiting clarity on their employment.

While the port authority said it was too early to quantify the redundancies, the ABC understands about 30 full-time equivalent operational roles could be axed.

It comes after two of the port's biggest customers — First Quantum Minerals' Ravensthorpe Nickel Operation and Mineral Resources' Yilgarn iron ore project — announced their closures.

Last week, Arcadium Lithium announced its Mt Cattlin mine near Ravensthorpe would also be mothballed.

The triple blow will significantly impact the port's export volume in 2025.

"It is clear that our labour demand in operations and maintenance will need to reduce in line with our adjusted trade volumes as we prepare for a new trade outlook in 2025," said Southern Ports chief executive Keith Wilks.

"We will continue to work closely with our workforce and union over the coming months to plan a way forward."

Urgent meetings about the redundancy process have been held this week between Southern Ports and the Maritime Union of Australia. 

'Toughness' an inspiration

According to its 2023 annual report, Esperance Port has about 150 staff and is the region's second-largest employer.

Last year it exported about 12.6 million tonnes of commodities, more than half of which were iron ore.

Assistant branch secretary of the Maritime Union's WA branch Jeff Cassar said while far from "a party atmosphere", Esperance Port employees were getting on with the job.

"I've watched these workers push through enormous difficulty during the COVID pandemic to ensure trade continued, as requested by the [former] premier," he said.

"There's a toughness amongst these workers that inspires.

'At a crossroads'

Mr Cassar implored the state government to offer "modest concessions" to various "junior" mining companies, which he said could help fill some of the export void left by the closure of the Yilgarn iron ore operation.

"They have sufficient mineral ore deposits to ensure high volumes of export for several decades," he said.

"We find ourselves at a crossroads now, and down one path there's an exciting future for communities all the way down from the Yilgarn, through the Goldfields region, right down to Esperance."

Ports Minister David Michael said the state government was in active consultation with the junior iron ore sector.

"We appreciate the concern of the Maritime Union of Australia for its members at the Port of Esperance and share their interest in developing new trade growth," he said.