Thursday, October 02, 2014
Friday, May 16, 2014
BY Yereth Rosen, Anchorage Daily News
Rock snot, a slimy-looking algae that vexes salmon and salmon fishermen, is not an alien invader but a homegrown threat gaining strength in changing water conditions, according to a new study by scientists from Dartmouth and Environment Canada.
Officially known as Didymosphenia geminata, which scientists shorten to didymo, it has existed in portions of Alaska for some eight centuries, said the study published online last week in the journal BioScience.
Only recently, though, has the nuisance algae been noticed, even in sites considered pristine, thanks to aggressive growth that spreads rock snot stalks in lakes, rivers and streams.
"It's in Patagonia. It's in Tierra del Fuego. It's in Alaska," said study co-author Brad Taylor of Dartmouth College. It is also in British Columbia, New York and various northeastern U.S. states. Sweden, Poland and Colorado see it, too.
Alaska officials have waged a crusade against rock snot. Alaska is among several states that ban felt soles in fishermen's waders; the state Department of Fish and Game cites felt's ability to absorb and transport a plethora of unwanted organisms to new places. The Alaska House this year passed a bill that allows state officials to mount a rapid response to eradicate invasive aquatic species and establishes a fund to pay for it; the bill died, however, without Senate action.
Explosion linked to phosphorus
But when it comes to combating rock snot in Alaska, anti-invader strategies may do little, according to Taylor's study. Core samples at Naknek Lake show that rock snot has been there since the year 1200, the study notes. As long as the didymo did not bloom, Taylor said, it went mostly unnoticed.
"Unless you scrubbed a rock and looked in a microscope, you would never know it's there," he said. "Absence of evidence was used as evidence of absence."
Wednesday, May 07, 2014
Spotted salamander is solar-powered - vertebrate/algae symbiote
Plants make food using photosynthesis, absorbing light to power a chemical reaction that converts carbon dioxide and water into glucose and releases oxygen. Corals profit from this reaction by housing photosynthetic algae inside their shells.
Spotted salamanders, too, are in a long-term relationship with photosynthetic algae. In 1888, biologist Henry Orr reported that their eggs often contain single-celled green algae called Oophila amblystomatis. The salamanders lay the eggs in pools of water, and the algae colonise them within hours.
By the 1940s, biologists strongly suspected it was a symbiotic relationship, beneficial to both the salamander embryos and the algae. The embryos release waste material, which the algae feed on. In turn the algae photosynthesise and release oxygen, which the embryos take in. Embryos that have more algae are more likely to survive and develop faster than embryos with few or none.
Then in 2011 the story gained an additional twist. A close examination of the eggs revealed that some of the algae were living within the embryos themselves, and in some cases were actually inside embryonic cells. That suggested the embryos weren't just taking oxygen from the algae: they might be taking glucose too. In other words, the algae were acting as internal power stations, generating fuel for the salamanders.
To find out if that was happening, Erin Graham of Temple University in Philadelphia, Pennsylvania and colleagues incubated salamander eggs in water containing radioactive carbon-14. Algae take up the isotope in the form of carbon dioxide, producing radioactive glucose. Graham found that the embryos became mildly radioactive – unless kept in the dark. That showed that the embryos could only take in the carbon-14 via photosynthesis in the algae.
The algae do not seem to be essential to the embryos, but they are very helpful: embryos deprived of algae struggle.
"Their survival rate is much lower and their growth is slowed," says Graham.Source: NewScientist
Tuesday, June 18, 2013
Source: Water Headlines
Sunday, March 10, 2013
To create the algae façade, the building is covered in bio-reactive louvers that enclose the algae. These louvers allow the algae to survive and grow faster than they would otherwise while also providing shade for the interior of the building. Additionally, the bio-reactors trap the heat energy created by the algae, which can then be harvested and used to power the building. Once the building is completed, it will be evaluated by scientists and engineers to allow for future research and adaptation for future building projects.
Read more: World's First Algae-Powered Building by Splitterwerk Architects Opens This Month in Germany | Inhabitat - Sustainable Design Innovation, Eco Architecture, Green Building
Source: Kristine Lofgren, Inhabitat