Shetland’s inter-island ferry service will move to a restricted timetable from Sunday morning.
Shetland Islands Council says the decision has been taken in order to preserve the overall resilience of the service.
The bus timetable has also been amended so that key workers can, if required, meet the appropriate ferry run.
The new timetables are expected to be in place until at least the end of January.
All ferries should be booked either by phone or online.
A similar approach was taken earlier this year, and the system has been slightly amended to deal with specific Covid-19 risks.
Chairman of the Environment and Transport Committee Ryan Thomson said: “We’ve taken this decision to preserve the overall reliability of the service.
“Should any of our crews be required to isolate due to contact tracing for Covid-19, this timetable allows for that to happen with the lowest possible impact on the wider service.
“I would like to remind folk that, under the current Tier 3 guidelines, our ferries and buses should be used for essential travel only.
“I understand that this may inconvenience some in the community, but it is important that we all do what we can to limit transmission of the virus, and protect our essential services.”