Elver fishermen say that the cold weather has delayed the start of the annual migration of baby eels up the River Severn.

The traditional way of fishing is to lower a hand net into the water. This year the River Severn is two degrees colder than normal. Millions of eels should be making their way upstream, but, says elver fisherman Wayne Dalton, it is simply too cold for them.

It's terrible. The water is too cold. The season ends in May. No one is going to catch any.

During the elver season the Environment Agency mounts nightly patrols, both on the river bank and in boats to make sure that anyone fishing for the tiny eels has a valid permit to do so.

With elvers fetching up to £150 per kilo, poachers may be tempted to fish illegally, but the patrols are equipped with state of the art technology: image intensifiers through which they can see using only the light from stars, and thermal imaging scopes which makes fishermen easy to spot as they appear to glow in the darkness because of their body heat.

An elver fisherman at night. Credit: ITV News West Country

Every year we prosecute some people for either fishing without a licence or fishing the wrong way. We have to make sure people are using the right equipment, for instance, if they were stringing illegal nets across the river they could catch thousands and thousands, and that would jeopardise stocks.

Environment Agency on patrol. Credit: ITV News West Country