kiwibird
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Big fish die off in Whangamarino wetland
NZPA
February 11, 2011, 5:47 pm
The deaths of thousands of fish over the past week in Waikato's Whangamarino wetland have been caused by very low levels of dissolved oxygen in the water, says the Department of Conservation (DOC).
...
"The drought at the end of 2010 exposed large areas of the wetland and rapid plant growth occurred in areas usually under water," Mr Hutchinson said.
"High rainfall in January compounded by the baked dry ground in the catchment meant water rapidly ran off into the wetland and water levels remained consistently high for about three consecutive weeks."
The decomposing plant matter started a bacterial process which depleted oxygen in the water. The warm humid weather experienced over summer had kept water temperatures high, thus enhancing bacterial growth.
....
Full story: http://nz.news.yahoo.com/a/-/top-stories/8819959/big-fish-die-off-in-whangamarino-wetland/
Tests by staff of the DOC had confirmed the lack of oxygen.
NZPA
February 11, 2011, 5:47 pm
The deaths of thousands of fish over the past week in Waikato's Whangamarino wetland have been caused by very low levels of dissolved oxygen in the water, says the Department of Conservation (DOC).
...
"The drought at the end of 2010 exposed large areas of the wetland and rapid plant growth occurred in areas usually under water," Mr Hutchinson said.
"High rainfall in January compounded by the baked dry ground in the catchment meant water rapidly ran off into the wetland and water levels remained consistently high for about three consecutive weeks."
The decomposing plant matter started a bacterial process which depleted oxygen in the water. The warm humid weather experienced over summer had kept water temperatures high, thus enhancing bacterial growth.
....
Full story: http://nz.news.yahoo.com/a/-/top-stories/8819959/big-fish-die-off-in-whangamarino-wetland/
Tests by staff of the DOC had confirmed the lack of oxygen.