SOPHISTICATED equipment has been installed to monitor the impact of the proposed new Tyne Tunnel on salmon.

The river, once heavily polluted, is now considered one of the country's cleanest, but there are fears that work on the £139m crossing, near Jarrow, could disturb migrating fish.

The country's most sophisticated monitoring equipment, including video cameras and a fish trap, has been installed at Riding Mill, near Hexham, in Northumberland.

It has been put in place by the Tyne and Wear Passenger Transport Authority and their consultants Arup and will be operated by the Environment Agency.

Sarah Peaty, ecological appraisal team leader from the Environment Agency, said: "With such a significant development, measures must be taken to minimise the impact of pollution upon the River Tyne and mitigation put in place to protect aquatic life.

"This facility is one of a number of measures that the agency believes are necessary to effectively manage any environmental impacts of the proposed tunnel.''

Arup director Richard Thurlow said: "This was a fascinating project that required solutions to a number of problems - not least how to video fish at night when they tend to move up the river and how to encourage them to swim into the trap."

Work on the crossing could start in 2004, finishing three years later, if it gets the go-ahead following a public inquiry.

It will entail deep dredging of the river to accommodate pre-fabricated sections.

Environmental and fisheries organisations had been concerned that work on the tunnel could affect the river's fish populations.