A SPECIES of rare and protected fish has been spotted in the region's rivers following improvements in river water quality.

The Environment Agency, working with local angling groups and Natural England, has been surveying North-East rivers searching for lamprey.

So far one spawning site on the River Wear and spotted a total of 20 adult sea lampreys have been counted.

In North Yorkshire, Natural England has a project underway in search for sea lampreys on the River Ouse.

River and sea lampreys are also expected to return to spawning grounds on the lower River Wharfe, Swale, Nidd and Ure.

Experts say the rare, jawless fish are a good indication of the high quality of the river water and scientists are continuing to search for more lampreys on the Wear and the Ouse river catchments.

Paul Frear, Environment Agency fisheries officer, said: “We welcome the return of the lampreys back to Yorkshire and the North East. The lampreys are like swallows. They return to the same spot to spawn within the same few days every year.

“These illusive fish are extremely selective with their spawning sites and will only nest where the water quality is good. Their appearance is a ringing endorsement of the water quality in these areas.”

Scientists say lamprey are extremely unusual. The most primitive fish in the world, it uses its mouth like a suction-cup to attach itself to the skin of a fish and rasp away tissue with its sharp probing tongue and teeth.

They outwardly resemble eels because they have no scales and an adult lamprey can range anywhere from 13cm to 100cm. They have large eyes, one nostril on the top of their heads, and seven gill pores on each side.

Claire Horseman, from Natural England, said: “We are hoping that the lamprey projects being undertaken by Natural England and the Environment Agency will help us better understand the migratory behaviour of these primitive species and the challenges that they face along their migratory route. With this increased understanding we can work towards restoring lamprey populations to their former status.”

During the Middle Ages lampreys were widely eaten by the upper classes throughout Europe, especially during fasting periods, because their taste is much meatier than that of other fish.

The deaths of two English kings, King Henry I and King John, are said to have been from overindulging on the fish.