Watermark Limnological Weighted Secchi Disc
- Silk screened with black and white quadrants
- Stainless steel hardware
- Built-in 24 oz. zinc sounding weight
|77912||Limnological weighted secchi disc|
|Usually ships in 3-5 days|
- 20 cm diameter secchi disc
- 24 oz. zinc sounding weight
- (1) Stainless steel hardware secchi disc
- (1) Built-in 24 oz. zinc sounding weight
In The News
Lake Tahoe is one of the clearest lakes in the United States, helped by the relatively small size of its surrounding watershed and the granitic basin it sits in.
Around 1968, the first year that its clarity was measured by Secchi disk, Tahoe’s blue waters were even clearer than they are today. Measurements at that time show an average yearly clarity of more than 100 feet. But such clarity was never reported again as its waters began a decline that lasted well into the 1990s.
At that point, the decline of average annual clarity measurements leveled out and stabilized, which is better news than it sounds.Read More
A monitoring initiative named for Secchi disks encourages people across the world to test the water nearby from the end of June through mid-July.
It’s called the Secchi Dip-in and its organizers want anyone with the means to test their local water to do so and report back. The database is open to contributions from June 29 through July 21.
Volunteers, monitoring groups and professionals alike can contribute data to the Secchi Dip-in database. Turbidity data is the main information Secchi Dip-in organizers want to see, but they won’t turn down any kind of water quality data people contribute.
They encourage interested environmentalists to go out with someone who is experienced in testing for water quality to ensure data is accurate.Read More
Each year in Germany, as many as 450,000 living fish undergo live animal experiments to test how fish-friendly hydroelectric power plants in the country are. The idea is to discover how readily the fish can move through hydroelectric turbine installations in order to ultimately reduce mortality rates.
Of course, subjecting live fish to a potentially deadly test to save others is a bitter irony. And it's one that a team of scientists from the RETERO research project hopes to eventually mitigate with a robotic fish for testing.
EM corresponded with Olivier Cleynen and Stefan Hoerner from the University of Magdeburg about the complex flow conditions that set the parameters for the project.Read More