marine organisms – Lightsources.org

X-ray studies at Berkeley Lab provide evidence for source of exotic assortment of melt debris

Mario Wannier, a career geologist with expertise in studying tiny marine life, was methodically sorting through particles in samples of beach sand from Japan’s Motoujina Peninsula when he spotted something unexpected: a number of tiny, glassy spheres and other unusual objects.
Wannier, who is now retired, had been comparing biological debris in beach sands from different areas in an effort to gauge the health of local and regional marine ecosystems. The work involved examining each sand particle in a sample under a microscope, and with a fine brush, separating particles of interest from grains of sediment into a tray for further study.

Image: Researchers collected and studied beach sands from locations near Hiroshima including Japan’s Miyajima Island, home to this torii gate, which at high tide is surrounded by water. The torii and associated Itsukushima Shinto Shrine, near the city of Hiroshima, are popular tourist attractions. The sand samples contained a unique collection of particles, including several that were studied at Berkeley Lab and UC Berkeley.
Credit: Ajay Suresh/Wikimedia Commons

A research team indicates that diatoms, can directly uptake iron from insoluble iron sediments, and thereby potentially affect atmospheric carbon dioxide level.

A research team from Columbia University indicates that diatoms, photosynthetic marine organisms responsible for as much as 20% of photosynthesis in the world’s oceans, can directly uptake iron from insoluble iron sediments, and thereby potentially affect atmospheric carbon dioxide level. Although iron is often present in the ocean, usually there is insufficient iron for diatoms and other organisms to grow quickly unless this iron is dissolved and in a form that can be used readily. This research establishes that iron from mineral phases can be quite bioavailable, and that the diatoms can use most forms of iron, but appear to have a preference for a specific form of iron, ferrous iron, in the mineral phases. This research is applicable to a wide variety of questions in earth and ocean sciences, including basic biology of nutrient acquisition, the coupling of physical and geological processes such as glaciers to climate and geoengineering.

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Picture: Glacial striations seen near Upsala Glacier, Argentina, where scientists collected glacial samples. This physical scraping produces sediments and dust that can fertilize plankton when it is delivered to the ocean.
Photo by Michael Kaplan/Lamont-Doherty Earth Observatory

Tag: marine organisms

Research on sand near Hiroshima shows fallout debris from A-Bomb blast

X-ray studies at Berkeley Lab provide evidence for source of exotic assortment of melt debris

Direct and Efficient Utilization of Solid-phase Iron by Diatoms

A research team indicates that diatoms, can directly uptake iron from insoluble iron sediments, and thereby potentially affect atmospheric carbon dioxide level.