Sealink advises that effective from Saturday, April 4, ferry schedules to and from Kangaroo Island will be reduced.
Coach connection and on-island shuttle services will still operate twice daily.
SeaLink's ferry and coach services are deemed as essential services, moving freight, emergency services, residents, landowners and Australia Post mail.
Kangaroo Island Council meanwhile has urgently asked the State Government's emergency controllers to close Kangaroo Island to non-essential travel, which may further impact on SeaLink services.
SeaLink meanwhile regardless of any new coronavirus restrictions will move to a one-ferry operation due to reduced demand.
"This move has of course been brought about by the COVID-19 situation, the cancellation of hundreds of bookings and the diminished number of forward travel bookings. At this stage we are just looking at the month of April," SeaLink SA general manager Peter Abbott said.
"We will move to a one ferry operation from Saturday, April 4, with the Spirit of Kangaroo Island ferry being the sole vessel to operate for the month.
"The SeaLion 2000 will be brought back to service if there are specific freight needs for the Spirit of Kangaroo Island, or as required. We are constantly reviewing the current situation and may need to make further amendments to our services through the month."
SeaLink will be contacting all customers affected by any of these changes and rebook them if necessary.
SeaLink's on-island shuttle which provides a public service each way between Kingscote, American River and Penneshaw will still depart twice daily, in the morning and afternoon with the only change at this stage being that the afternoon service will now depart Kingscote at 3pm instead of the usual 5.30pm.
Australia Post in Kingscote have been advised of the earlier mail collection time; however, some collections and deliveries may be affected by these changes.
Ferries will be scheduled to depart Penneshaw at 7.30 AM, 10.30 AM, 1.30 PM and 4.30 PM and return from Cape Jervis at 9.00 AM, 12.00 PM, 3.00 PM and 6.00 PM Monday to Friday. There may be less departures on the weekend depending on demand.
The SeaLink Connection coach which provides a public service each way between Adelaide and Cape Jervis and connects with morning and evening ferries, will still depart twice daily, in the morning and afternoon with the only change at this stage being the afternoon service from Cape Jervis which will now depart at 5.30pm instead of 8.30pm.
Mr Abbott added that SeaLink will also be advising these changes via an eNewsletter to Kangaroo Island residents and Premier Club members (landowners), who are on their newsletter database.
For anyone wishing to find out more about these changes please visit the Timetable page on the SeaLink website, or residents can call 8551 7222 and Premier Club members and other customers can call 13 13 01.