Western Australia has introduced new protocols for seafarers looking to disembark from ships at its ports following a spike in reported Covid-19 cases.

Over the past few weeks, the state that is home to some of the countries largest commodity ports has seen several vessels arriving with Covid-19 cases aboard.

“We have now implemented new protocols in Western Australia requiring all crew members, Australian-based or international who disembark from international maritime journeys in Australia, to undergo two weeks of quarantine in a state-run hotel,” state premier Mark McGowan said.

“Previously, national guidelines had considered time spent on the ship at sea as quarantine, provided that ship had been at sea for at least two weeks.”

McGowan, who said Western Australia was the nation's first state to change this requirement, had earlier claimed that ships arriving with the virus on board were one of the state’s “weakest links” and the “biggest risk to our way of life”.

Western Australia state premier Mark McGowan visits a hotel, where ship crews are going through quarantine. Photo: Mark McGowan

Under the new guidelines, Australian crew members wishing to disembark a vessel to enter the country through Western Australia can now only do so at Perth or be immediately transferred to the city by a prearranged and approved charter flight. They then must serve a full 14 days in hotel quarantine.

“This is an important and necessary change to keep our community safe from the increasing cases of Covid-19 that we are seeing on board these vessels,” McGowan said.

Separately, Australian authorities said the 25 confirmed Covid-19 cases from the 12,900-dwt livestock carrier Al Messilah (built 1980), as well as all other non-essential crew from the vessel, are now in hotel quarantine.

A skeleton crew remains on the vessel to perform required tasks and a deep cleaning of the Al Messilah is now said to be underway.

Meanwhile, NYK Line’s 83,400-dwt bulker Key Integrity (built 2011) has seen a second crew member test positive for Covid-19 after all members of the ship’s crew were tested.

The remaining 18 crew members have all tested negative. The two positive cases are still isolating in their cabins aboard the vessel.