The shift supervisor of a cargo ship that ran aground in a pristine marine reserve near the French Mediterranean island of Corsica last year was given a suspended sentence today for sleeping on the job.

The 90-metre Rhodanus, transporting 2,650 tonnes of steel coils, failed to heed repeated calls from traffic controllers over a period of 50 minutes to change course, and smashed into the Bonifacio Strait nature reserve in the early morning hours.

Even a helicopter was sent out to raise the alarm, to no avail.

"I sat down on the couch, made a coffee, and fell asleep. The sound of a crash woke me up," the 44-year-old shift supervisor told investigators after the accident last October. 

There were no injuries nor pollution as a result of the crash.

The supervisor and the sailor at the helm, both Russians, were given six-month suspended sentences Friday by a court in Marseille in southern France, as well as a fine of €3,000 each.

They were also prohibited from sailing in French waters for three years.

Neither were present in court.

Prosecutor Franck Lagier pointed out a series of "failings and negligence" on board the vessel he said was operating like a "ghost ship without a commander".

With his supervisor asleep, the sailor on duty had deactivated a "dead man switch" - which activates an alarm after prolonged human inactivity - because the noise bothered him.

The supervisor had failed to set an alarm to rouse him from his sleep for the passage through the sensitive marine reserve area.

The ship got lodged in sand without tilting, and did not shed any oil.

The Bonifacio Strait reserve, stretching over 80,000 hectares, is a scuba divers' paradise with several small islands in the strait separating Corsica from Italy's Sardinia.