didymo algae update new zealand

The samples sent for analysis from Ohau and Tekapo rivers came back negative.
Thus far, only a small number of rivers have been confirmed
Oreti, Mararoa , upper and lower Waiau in southland
Hawea river and Clutha river catchment in Otago
Buller river on West coast / NW Nelson

Thing is, a bloom is the exception rather than the rule. Didymo is present in many North american and BC rivers whrere it has not bloomed. Dont get me wrong, this is a very serious threat to our clean green image, and the health of our rivers.
Rivers with a lot of fine stream bed material such as Mataura may not be that badly affected if didymo is found there eventually, as with the small stones / gravel / silt making up the streambed didymo will have trouble establishing itself, due to the constantly moving riverbed. Growth may be smothered, or may not establish at all. Didymo prefers large stones / stable structure on which to establish, so that meay be a positive for us.

Please, anyone visiting any river / stream in NZ, be careful of moving from catchment to cathment. Please decontaminate all equiptment before visiting other waters with a 2% bleach solution, or 5% detergent, antiseptic or salt solution (2 large cupfuls per 10l water) or ensure gear is completley dry for 48 hours before future use. Remember that this 48 hour period begins AFTER the gear / clothing is COMPLETLEY dry.

Otago regional council are proposing to close UNAFFECTED waters to prevent the spread, but I cant see this going through, not without a large battle.

If the government could reactso quickly and efficiently to the recent foot and mouth scare on waiheke island, why havent similar resources been thrown into the didymo debacle? All this action / proposals now, but remember, it was confirmed in mararoa and lower waiau LAST october, and known about 3 years before that!

Heres hoping the new zealand public, and touring anglers / outdoors entheusiests are well informed of the controlls needed to help prevent further contamination of our rivers / lakes

will keep you all posted

Chris



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Mataura river fly fishing
http://www.troutsafaris.co.nz