Sentences with phrase «diatoms in»

The Cretaceous also saw the first radiation of marine diatoms in the oceans.

A new mechanism for emplacement and concentration of diatoms in subglacial deposits.

Diatoms in South Pole ice: Implications for eolian contamination of Sirius Group deposits.

Unlike most regions of the global ocean which do not contain sufficient nitrogen or phosphorus for sustained phytoplankton growth, diatoms in the remote waters of McMurdo Sound were starving from lack of iron and deficiency of vitamin B12.

Domoic acid, a neurotoxin that causes amnesic shellfish poisoning in humans, is produced by marine diatoms in the genus Pseudo-nitzschia.

Not exact matches

The smoking — or in this case, oozing — gun is a layer of siliceous microfossils called diatoms.

Scherer would later find dozens of crushed diatom shells in his samples — possible remnants of microscopic aquatic organisms from when the site of Lake Whillans was a shallow seafloor.

As an IIE - SRF fellow at the University of Gothenburg, Al - Handal is again able to use his expertise in taxonomy of marine diatoms, a type of microalgae, with the added advantage of direct access to a scanning electron microscope, which he didn't have in Iraq.

The aim of my PhD is to use the distribution of diatom species preserved in sediment cores across the Scotia Sea to reconstruct the position of major ocean boundaries and water masses through time.

The diatoms also have proliferated in places like New Zealand and the Delaware River.

Previously, many water managers in the region had believed that the algae blooms of the diatom Didymosphenia geminata — which resemble blobs of wet toilet paper or shag rugs — resulted from an invasive species problem starting in the mid-2000s that could be fixed by regular washing of fishing gear and other sanitation measures.

At that time, there were lots of nutrients in the ocean water there, because small organisms called diatoms, which have silica shells, were able to thrive.

This will improve our ability to reconstruct ocean conditions from the fossil diatoms preserved in the ocean sediments.

During this cruise we are looking at the diatom species currently living in the surface waters in order to develop our understanding of their habitats.

Bacteria and diatoms inhabit those liquid veins, and Hajo Eicken, a glaciologist at the University of Alaska at Fairbanks, suspects that similar habitats could exist in the lower, warmer layers of ice on Europa, and perhaps on the other moons as well.

Worms writhe in the goo, clams bask in the bacteria, herds of sea cucumbers dine on diatoms and sea stars scurry across the pitch black landscape.

He spotted the glassy shards of ancient diatom shells — the remains of microscopic phytoplankton that lived here at warmer times in the past, when a shallow sea covered much of West Antarctica.

To bury carbon at sea requires promoting particular species in the bloom, such as diatoms — shelled algae.

Dumping iron into the ocean stimulates blooms of diatoms that pull down carbon dioxide in the atmosphere — but only under the right conditions

Biologists from the University of Geneva (UNIGE), Switzerland, have succeeded in establishing a water quality index based solely on the DNA sequences of the diatoms present in the samples, without needing to identify each species visually.

In a presentation at a recent ocean acidification conference, Tatters reported that the more CO2 and the less silicate, the higher the diatom's toxin production — more than doubling at the level of dissolved CO2 scientists expect the oceans to reach by 2100.

But he notes that others have not seen as dramatic a decrease in copepod reproductive success during diatom blooms elsewhere and warns that the Adriatic's heavy pollution may have enhanced the effect.

Then in 1997 and 1998, they and their colleagues sampled copepods in the Adriatic Sea during diatom blooms in winter, when the copepods feast primarily on diatoms, and during the summer, when diatom numbers are down and copepods eat a more mixed diet that includes other algae.

Ecologist Adrianna Ianora and neurobiologist Antonio Miralto of the Naples Zoological Station first noticed a diatom - related drop in copepod hatching rates in laboratory studies.

Back in the laboratory, the group isolated three compounds called aldehydes produced by the diatoms.

Out of the vast diversity of plankton in the oceans, the worst offenders are a few species of diatoms, dinoflagellates and cyanobacteria, collectively called harmful algae.

Some researchers say that the ice sheet must have melted during the Pliocene, allowing trees to cover the mountains and diatoms to thrive in the seas.

Diatoms exist in both fresh and brackish environments.

As the temperature and acidity of a test tank climb, diatoms that dominate the cold northern oceans fall off steeply in number — an ominous sign, given that they currently support by far the richest fisheries in the world.

Another person, brought in to work on a project on unicellular algae, had «never looked at diatoms before he came here,» explains Gibby, but «he was very good at diving... he had to be able to dive to collect the specimens.»

Some diatoms can even be found in moist rocks, soils, and bark.

Beginning about 7,850 years ago, the variety and number of diatoms and water fleas found in the sediment change in a way that indicates the water was becoming shallower and murkier.

Diatoms are a favorite tool among ecological and evolutionary researchers because their hard silica shells are often well preserved — and they have been found in virtually every type of water body on Earth, both fresh and salt, from oceans to farm ponds, from the Great Lakes to the West African coast.

In turn, the crustacean primarily feeds on diatoms that grow directly on or under the sea ice.

Few diatoms grew in Smetacek's bloom because he fertilized waters that had low levels of silicon, which is required for their shells.

But biogeochemist Kenneth Coale, director of Moss Landing Marine Laboratories in California, estimates that the silicon - rich southern part of the Southern Ocean would deliver up to twice as much potential carbon sequestration as the northern area Smetacek fertilized, in large part because of the diatoms and associated ecosystem dynamics.

They compared isotope measurements on the silica skeletons of diatoms, which store environmental signals from the ocean's surface, with isotope signals from radiolarians, which live in deeper water layers.

But silicon (an element that has properties both of metals and non-metals) seems to occur only in bioinorganic compounds, such as those in the silica shells of the single - celled algae diatoms.

The most distinct trend was a decline in the abundance of large - sized, filamentous diatoms and an increase in small diatoms.»

This could likely have implications for the zooplankton that usually graze on larger diatoms and in turn the fish that eat those zooplankton.

In a word, diatoms.

One beneficiary of this young researcher exchange program was Matthew Julius, who studies the evolution of diatoms, a group of microscopic algae, now at St. Cloud State University in Minnesota.

Diatoms are unicellular algae that are native in many waters.

So many diatoms died, in fact, that they overwhelmed any natural systems for decay and fell in large numbers below 500 meters in depth.

In tropical countries like India with an abundance of sunlight, biofuel - producing solar panels containing local diatoms could be placed in every villagIn tropical countries like India with an abundance of sunlight, biofuel - producing solar panels containing local diatoms could be placed in every villagin every village.

Scientific analysis of diatom oil has shown that it is very suitable for use as biofuel, says T. V. Ramachandra, a professor of ecological sciences at the Indian Institute of Science (IISc) here who is working on this project with IISc researchers Durga Mahapatra and Karthick Balasubramanian, along with Richard Gordon, a radiology professor at the University of Manitoba in Winnepeg.

Georgia Tech research published online Monday in Nature Communications indicates that diatoms stuff more iron into their silica shells than they actually need.

Among their findings: in streams with the amphetamine addition, the growth of biofilms was significantly suppressed, the composition of bacterial and diatom communities changed, and aquatic insects emerged earlier.

Diatoms would float about in a nutrient - rich water solution and produce oil when exposed to sunlight.

Electron micrograph of an Antarctic sea ice diatom, Amphiprora, with attached bacterial cells, illustrating the association between diatoms and bacteria in the Southern Ocean ecosystem