A cetacean, believed to be a harbour porpoise, was spotted in the River Trent at Bole on Wednesday 29 February.
Harbour porpoises are occassionally sighted in tidal parts of the River Trent, as a few miles north of Gainsborough the river branches into the Humber Estuary and out to the North Sea.
We don't know who saw it, but a recording was made to the Nottinghamshire Biological and Geological Record Centre and then to the County Mammal Recorder.
Did you see it? We'd love to hear from you if you did.
Unfortunately there is no photo that we know of, so this one was borrowed from the Manx Whale and Dolphin Watch website.