The Good, the Bad, and the Algae
NASA Science News for July 2, 2015
June 26, 2015: Algae are complicated. The little plants can be both good and
bad.
Single-celled algae called phytoplankton are a main source of food for fish
and other aquatic life, and account for half of the photosynthetic activity
on
Earth-that's good.
But certain varieties such as some cyanobacteria produce toxins that can
harm
humans, fish, and other animals. Under certain conditions, algae populations
can grow explosively -- a spectacle known as an algal bloom, which can cover
hundreds of square kilometers. For example, in August 2014, a cyanobacteria
outbreak in Lake Erie prompted Toledo, Ohio, officials to ban the use of
drinking water supplied to more than 400,000 residents.
With support from NASA, the EPA has developed an app to track algae that can
threaten fresh water supplies.
http://science.nasa.gov/science-news/science-at-nasa/2015/26jun_algae/
In the United States alone, freshwater degradation from "bad" algae costs
the
economy about $64 million a year.
NASA, the U.S. Environmental Protection Agency (EPA), National Oceanic and
Atmospheric Administration, and U.S. Geological Survey are doing something
about it. NASA has long used Earth observing satellites to locate algal
bloom
outbreaks in the ocean. But now, this unique satellite data will be
routinely
produced in a form that helps US water quality managers monitor our
freshwater. Water quality managers will soon, with a peek at their cell
phones, have an answer to "how's the water?"
The four agencies are working on a joint project, sponsored by NASA, to
transform satellite data into an indicator of cyanobacteria outbreaks in our
freshwater supply. The data will be integrated into an EPA Android smart
phone
application so environmental officials can see - at a glance - the condition
of a specific water body.
"With our app, you can view water quality on the scale of the US, and zoom
in
to get near-real-time data for a local lake," explains the EPA's Blake
Schaeffer, Principal Investigator for the project. "When we start pushing
this
data to smartphone apps, we will have achieved something that's never been
done - provide water quality satellite data like weather data. People will
be
able to check the amount of 'algae bloom' like they would check the
temperature."
Here's how it works:
A harmful species of cyanobacteria emits chlorophyll and fluorescent light
at
various points in their life cycles. Landsat and NASA's Moderate Resolution
Imaging Spectroradiometer (MODIS) can detect these "ocean color" signals,
which reveal the location and abundance of cyanobacteria. The project team
will collect this data for freshwater bodies and convert it into a form
accessible through web portals and the EPA mobile app. In addition to MODIS,
they'll draw data from the European Space Agency's Sentinel-2 and Sentinel-
3.
With early warning about a developing bloom, officials at water treatment
plants will be better able to determine when, where, and how much to treat
the
water to keep consumers safe. That means unnecessary -- and expensive --
overtreatment may be avoided. The data will also help park managers alert
swimmers, boaters, and other recreational users to hazardous conditions.
Says NASA Administrator Charles Bolden: "We're excited to be putting NASA's
expertise in space and scientific exploration to work protecting public
health
and safety."
The project will also help scientists understand why "bad" algae outbreaks
occur. By comparing the color data with landcover change data, they'll
learn
more about environmental factors that spur algal growth. The result: better
forecasts of bloom events. So we'll know when an algae bloom is safe or
harmful.
Regards,
Roger
--- D'Bridge 3.99
* Origin: NCS BBS - Houma, LoUiSiAna (1:3828/7)
|
