Sentences with phrase «on diatom»

Our results support the use of short - term manipulative experiments spanning weeks as proxies to understand the potential effects of global change forcing on diatom community structure over longer timescales such as years.

However, elevated atmospheric CO2 concentrations and ocean acidification may also have an adverse impact on diatom growth, causing a decrease in cell size and possible further changes in phytoplankton composition.

«Generally, a polar bear eats things that start feeding on a diatom, and is probably not fed by something that feeds on Prochlorococcus, for example,» Dutkiewicz says.

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.

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.

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

As he and his collaborators put it, «with at least a boundary layer of water on the diatoms, secreted oil droplets would separate under gravity, rising to the top of a tilted panel forming an unstable emulsion, which should progressively separate.

More locally, Moros et al. (2006) record substantial environmental changes in Disko Bugt sediments at w4 ka based on diatoms and sediment physical proxies.

Not exact matches

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.

Bacteria, diatoms, and other organisms spend their winters there, presumably subsisting on a bare minimum of nutrients.

When the weather warms and no ice sits upon the seas, the sediment on the ocean floor is mainly organic: remains of plankton and diatoms.

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.

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.»

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.

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.

A glassy object snapped into focus — a round disk, serrated on the edge, perforated with dimples — the shell of an aquatic microscopic organism called a diatom.

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

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.

A different group of bacteria, also relying on the phytoplankton for food and energy, appear to compete with the diatoms for the precious vitamin, and all three groups of microbes are competing for iron, which, due to the extreme remoteness of the Southern Ocean, is a scarce and consequently invaluable resource.

Neither are fungi, diatoms, nematodes, tardigrades, slime moulds, algae or most other species on the planet.

In 1998, sea lion deaths on the California coast also were associated with domoic acid, which entered the food chain via toxigenic diatoms, which were eaten by anchovies that in turn were eaten by the sea lions.

We incubated a natural diatom community from coastal New Zealand waters in a short - term incubation experiment using a factorial matrix of temperature and CO2, and measured effects on community structure.

We assess atmospheric versus oceanic influences on glacial discharge at this location, using analyses of diatom geochemistry to reconstruct atmospherically forced glacial ice discharge and diatom assemblage ecology to investigate the oceanic environment.

These tiny green diatoms generate nearly half of all the planet's primary production − that is, the food on which all other diners must ultimately depend.

Multi-centennial-scale changes in East Asian typhoon frequency during the mid-Holocene This study reconstructs a record of typhoon frequency over the Korean Peninsula during the mid-Holocene using mineral components and diatom assemblages in deposits of Lagoon Hyangho, located on the east coast of the peninsula.

On the basis of pollen and diatom records, we evaluated past floods, typhoons, and agricultural activities in this area which are sensitive to the hydrological conditions in the western Pacific.

His position: • No evidence of increasing lake clarity as a result of secchi measurements since 1946 • The interplay of stratification and plankton productivity are not «straightforward» • Challenges O'Reilly's assumption on the correlation of wind and productivity - the highest production is on the end of the lake with the lowest winds • A strong caution using diatoms as the productivity proxy (it is one of two different lake modes) • No ability to link climate change to productivity changes • More productivity from river than allowed for in Nature Geopscience article • Externally derived nutrients control productivity for a quarter of the year • Strong indications of overfishing • No evidence of a climate and fishery production link • The current productivity of the lake is within the expected range • Doesn't challenge recent temp increase but cites temperature records do not show a temperature rise in the last century • Phytoplankton chlorophylla seems to have not materially changed from the 1970s to 1990s • Disputes O'Reilly's and Verbug's claims of increased warming and decreased productivity • Rejects Verburgs contention that changes in phytoplankton biomass (biovolume), in dissolved silica and in transparency support the idea of declining productivity.

Global solar irradiance reconstruction [48 — 50] and ice - core based sulfate (SO4) influx in the Northern Hemisphere [51] from volcanic activity (a); mean annual temperature (MAT) reconstructions for the Northern Hemisphere [52], North America [29], and the American Southwest * expressed as anomalies based on 1961 — 1990 temperature averages (b); changes in ENSO - related variability based on El Junco diatom record [41], oxygen isotopes records from Palmyra [42], and the unified ENSO proxy [UEP; 23](c); changes in PDSI variability for the American Southwest (d), and changes in winter precipitation variability as simulated by CESM model ensembles 2 to 5 [43].

Although this upwelling deceases surface pH and provides more CO2, diatoms still rely on bicarbonate transporters and carbonic anhydrase to ensure an adequate supply of CO2 for photosynthesis.

Based on pollen and diatom studies (Kauppila 2002), the MWP was a two - stage event.

Our experiments suggested that warming was a dominant forcing factor on the outcome of interspecific competition between diatoms.

Inter-specific competition was found to be similar in both the unconditioned natural and the conditioned artificial community, suggesting that for diatom communities, short - term manipulative experiments may be used to predict the effects of long - term environmental forcing on community structure.