Camera footage shows otters on the River Brain in Witham
The otter population has increased in Essex say the Essex Wildlife Trust who have been tracking them for 20 years.
The trust said the otters started in a small part of north Essex and were now spreading throughout the county.
Using a monitoring raft and camera, volunteer Sue has seen the mammals on a stretch of the River Brain in Witham.
"We knew we had otters because we had surveyed each of the bridge points at either end of the river," said river search volunteer, Sue.
The camera has picked up some remarkable footage of otter activity on the river.
"Each time I see the footage it is a huge wow factor for me," said Sue.
"It's so exciting to see them in my garden, almost, and on this stretch of the water. It's just magnificent."
The footage shows a dog otter on his own and a female with two cubs.
"If we carry on monitoring as long as possible we might be able to see the story as it unfolds with this family," said Sue.
Witham Town council has been involved in improving the area around the River Brain since talking over the management of the river walk from Braintree District Council.
"We've been aware of the need to make it as diverse as possible for the benefit of not only the public in the town, but for the local town's wildlife," said Councillor, Barry Fleet.
"Obviously, we wanted to enhance the work we've done here, and I think it has proved the point really.
"The more diverse the habitat, the more you benefit from wildlife moving in," he added.