Most northerly bottlenose dolphin population 'stable'
The world's most northerly resident population of bottlenose dolphins is "stable", according to new research.
Almost 200 dolphins are found in the North Sea and the animals are frequently seen in the Moray Firth.
Scottish Natural Heritage (SNH) commissions a report on the health of the population every six years.
Researchers from the University of Aberdeen, drawing on about two decades of studies, have deemed the numbers to be stable, or increasing.
The latest research work was carried out in the Moray Firth Special Area of Conservation (SAC).
Wildlife spotters who come to the shores of the firth to see and photograph the bottlenose dolphins contribute an estimated £4m to Scotland's economy a year, according to other work by the university.
Morven Carruthers, SNH policy and advice officer, said: "We can say with some confidence that the population of bottlenose dolphins on the east coast of Scotland is stable or increasing.
"And the number of dolphins using the Moray Firth SAC between 1990 and 2010 appears to be stable.
"However, this population is considered vulnerable due to being small and isolated from other populations."
She added: "The east coast bottlenose dolphins are a special part of Scotland's nature and wildlife and a major tourist attraction, and it is encouraging to see that the population is currently stable."
The Moray Firth SAC extends from the inner firth to Helmsdale on the north coast and Lossiemouth on the south coast.
Bottlenose dolphins are protected under the European Union Habitats Directive.