Why is it that a product line
used for decades is only getting this sort of fundamental testing now? Or was it tested in house and the results simply
fudged.
We have been looking for a
smoking gun on the loss of frog populations for as long. Now we have an awfully good one and maybe it
is not Roundup.
Impacting the environment with
chemicals has been ongoing for half a century.
It is time to do a broad study on environmental health just about everywhere
to determine the general impact of modern agricultural practices. We need to particularly uncover what is
cumulative out there.
It will take a century for natural
methods to fully take over the biome again and this can be sped by determining
those agents that are clearly a problem
Common fungicide wreaks havoc on freshwater ecosystems
by Staff Writers
Chlorothalonil, one of the world's most common fungicides used
pervasively on food crops and golf courses, was lethal to a wide variety of
freshwater organisms in a new study, University of South Florida researchers
said Wednesday.
Biologists Taegan McMahon and Jason Rohr, co-authors of the study
published in the journal Ecology Letters, report that chlorothalonil killed
amphibians, snails, zooplankton, algae, and aquatic plants below estimated
environmental concentrations previously deemed safe by the U.S.
"Some species were able to recover from the chemical assault, but
the ecosystem was fundamentally changed after its exposure to
chlorothalonil," Rohr said.
The four-week study was conducted in a series of 300-gallon tanks used
to mimic pond conditions. It follows a 2011 laboratory study conducted by
McMahon and Rohr that found that ecologically-relevant concentrations of
chlorothalonil killed four species of amphibians.
"Although our new study is the only reported community- and
ecosystem-level experiment on chlorothalonil, our results are consistent with
several direct toxicity studies conducted in the laboratory and with
observations in the field," McMahon said.
Chlorothalonil kills molds and fungus by disrupting cellular respiration,
an essential process for most multicellular organisms on the planet. Like the
infamous DDT, chlorothalonil is a member of the organochlorine chemical family.
Fifty years after the book "Silent Spring" led to a ban on
most forms of the pesticide DDT, chlorothalonil is one of a few organochlorine
pesticides still registered for use in the U.S. ,
Europe and Australia
"In addition, to reducing biodiversity and altering ecosystem
functions, chlorothalonil reduced the decomposition of waste, an important
service that freshwater ecosystems provide to humans," McMahon added.
"Interest in the relationship between biodiversity and ecosystem
functions stems at least partly from the concern that anthropogenically-driven
declines in biodiversity will reduce or alter the benefits offered by
ecosystems," Rohr said. "Surprisingly, however, this is one of the
first studies to actually manipulate an anthropogenic factor and link it to
changes in ecosystem functions mediated by declines in biodiversity."
"This is important because many species in ecosystems might
contribute little to ecosystem functions or are functionally redundant with
other species, and thus declines in biodiversity do not always affect the
functions and services of ecosystems," Rohr said.
McMahon and Rohr encourage further research on effects of anthropogenic
factors on ecosystem functions in systems with complex food webs and the
re-evaluation of the safety of chlorothalonil.
No comments:
Post a Comment