Video | Business Headlines | Internet | Science | Scientific Ethics | Technology | Search

 


DCD may have unintended effects on aquatic environment


DCD may have unintended effects on aquatic environment: Otago research

University of Otago researchers have discovered that run-off of the agrichemical DCD may adversely affect some aquatic eco-systems by disrupting natural processes.

The recently-withdrawn chemical had been spread on many New Zealand paddocks to block high rates of microbial nitrification thus reducing greenhouse gas emissions and nitrate leaching into waters.

Findings from the Otago study, which is the first to investigate ecological impacts of DCD residues in aquatic eco-systems, are published this month in the international Journal of Agriculture, Ecosystems and Environment.

The study, led by Department of Zoology researcher Dr Marc Schallenberg, detected DCD residues in streams in Otago’s lower Taieri Plain in concentrations that cause natural nitrogen transformation processes to be disrupted in aquatic ecosystems.

Dr Schallenberg conducted laboratory experiments showing that in a wetland system, the presence of DCD inhibits the processes of nitrification and denitrification, two natural processes that help to purify and detoxify waters of ammonium by converting it to nitrate and inert nitrogen gas, respectively.

“While DCD’s inhibition of nitrification on land is desirable as it reduces the amount of nitrate entering streams, its similar inhibitory effects within aquatic environments is undesirable, as this could lead to ammonia toxicity in fish and other species, or increased incidences of algal blooms.”

Dr Schallenberg says research on downstream impacts of DCD should contribute to a more complete cost-benefit analysis of DCD use, should the DCD withdrawal by Fonterra be reversed in the future.

© Scoop Media

 
 
 
 
 
Business Headlines | Sci-Tech Headlines

 

China Shopping: NZ-China FTA Upgrade Agreed Among Slew Of New Deals

New Zealand Prime Minister Bill English and China Premier Li Keqiang signed off a series of cooperation deals spanning trade, customs, travel and climate change and confirmed commencement of official talks on an upgrade to the nine-year old free-trade agreement between the two countries. More>>

ALSO:


Media: TVNZ Flags Job Cuts To Arrest Profit Decline

Chief executive Kevin Kenrick said the changes were aimed at creating "a sustainable future video content business for TVNZ in an ever-changing media market." More>>

ALSO:

Reserve Bank: Wheeler Keeps OCR At 1.75%

Reserve Bank governor Graeme Wheeler kept the official cash rate unchanged at 1.75 percent, as expected, and reiterated his view that the benchmark rate doesn't need shifting for the foreseeable future. More>>

ALSO:

Trade Plans: Prime Minister's Speech To International Business Forum

"The work to improve public services, build infrastructure, and solve social problems is possible only because we have enjoyed sustained, solid economic growth. A big reason for that is the Government’s consistent agenda of economic reform, and our determination to open up more opportunities for trade with the world." More>>

ALSO:

Get More From Scoop

 
 
 
 
 
 
 
 
Sci-Tech
Search Scoop  
 
 
Powered by Vodafone
NZ independent news