THOUSANDS of Australian fly fishers who make an annual pilgrimage to New Zealand can leave their felt-soled wading boots behind. 

This follows NZ's Conservation Minister agreeing in principle with a Fish and Game New Zealand submission to ban felt-soled wading boots for freshwater fishing.

A statement by Bryce Johnson, chief executive of Fish and Game NZ, said that, if approved, the ban would be effective from October 1 and would apply to freshwater anglers in all NZ waterways, except those within the Taupo fishery.

Felt-soled boots are considered a high-risk vector or carrier of microscopic aquatic organisms such as Didymo (Didymosphenia geminata), which is also known "rock snot'' by Kiwi anglers.

Didymo was first seen on NZ's South Island in 2004.

Preventing the spread of Didymo is an important aspect of ban. It is believed that felt soles carry are an effective vector for pest organisms.

Mr Johnson said that some opposing the ban cited the safety provided by felt-soled boots. Because felt, or fibrous, soles provide a good grip on slippery boulders, they are popular with anglers.

Australia's Department of Agriculture, Fisheries and Forestry has listed Didymo as a serious pest.

While not in Australia, it has invaded rivers and lakes in Europe, Asia, North America and New Zealand.

Didymo comprises millions of microscopic cells that can't be seen until a large colony has formed - by which stage it is almost impossible to eradicate. A single live cell is all that is required for Didymo to establish and spread.

DAFF says there is a significant risk that Didymo could enter, establish and spread in Australia via fishing equipment used in freshwater lakes, streams or waterways overseas.

The department advises that before bringing fishing equipment back to Australia, it should be cleaned, dried and presented to a quarantine officer for inspection upon arrival.

For more information, visit www.aqis.gov.au/icon