Water firm uses DNA test on pond water to detect newts

Ecologists can use the eDNA analysis on pond water to see if great crested newts are living there

A water firm has started using a new test on pond water to detect the presence of great crested newt DNA where building work is planned.

The method was approved by Natural England in March and has been used since then by Wessex Water.

Ecologist Jamie Bowkett said the ability to test for the presence of the newts would "probably halve our costs".

So far the tests have been used for sewer building in Frome Valley, Somerset and South Gloucestershire.

'Less intrusive'

As great crested newts are a European protected species their habitats cannot be destroyed or damaged.

The technique known as eDNA analysis involves taking water samples from ponds and sending them off to government approved labs for trace testing of newt DNA.

Mr Bowkett said: "Traditionally newt surveying would mean visiting all ponds within 250 metres of a new development at least four times searching for newts during night with torch lights and using bottle traps for live capture.

"Using eDNA analysis is much less intrusive and means only one visit to a pond is required, saving time and resources."

The traditional method would cost around £2,000 to test five or six ponds, compared to a £700 eDNA test for five or six ponds, he added.

The tests can only be carried out between April and October when newts are active.

If the samples come back positive further site visits can then be made to establish the size of the colony and see if it is a breeding site.

The firm revealed that due to the success of its tests on the new 5km sewer between Frampton Cotterell and Bradley Stoke and the Frome Valley Relief Sewer, the method will be used again from April next year for its planned projects.