Whirlpools, or eddies, swirl across the surface of the North Atlantic Ocean sustaining phytoplankton in the ocean's shallower waters. There, the phytoplankton can get plenty of sunlight to fuel their growth, keeping them from being pushed downward by the ocean's rough surface. The result is a burst of spring and summer color atop the ocean's waters. Read more in this news release and photo gallery.
Credit: NASA Earth Observatory
Scientists have discovered that marine diatoms, tiny phytoplankton abundant in the sea, have an animal-like urea cycle, and that this cycle enables the diatoms to efficiently use carbon and nitrogen from their environment. Read more in this news release.
Credit: Alessandra De Martino, Ecole Normale Superieure, Paris
Mario De Stefano at Second University of Naples, Italy, and his collaborators have been studying diatoms--microscopic algae, and they believe the organisms' cellular structure could inspire the design of solar panels. An illustration by De Stefano, a marine biologist, demonstrates the principles of biomimeticism, which involves looking to natural organisms to see our future. Learn more in this news image.
Credit: Mario De Stefano, Antonia Auletta and Carla Langella; Second University of Naples
Microscopic photograph of the large-cell diatom algae Chaetoceros sp., which are part of the annual phytoplankton spring bloom--microscopic algae suspended in water--in the Baltic sea. Learn more in this news image.
Credit: Ulrich Sommer, IFM-GEOMAR Kiel
The Division of Polar Programs of the Directorate for Geosciences manages and initiates NSF funding for basic research and its operational support in the Arctic and the Antarctic. The funds are provided as NSF grants to institutions (mainly U.S. universities), whose scientists perform the research at the institutions or in a polar region, and as cooperative agreements or contracts to support organizations including contractors and the U.S. military.
The seas around Antarctica can, at times, resemble a garden. Large-scale experiments where scientists spray iron into the waters, literally fertilizing phytoplankton, have created huge man-made algal blooms. Such geoengineering experiments produce diatoms, which pull carbon dioxide out of the air. Experts argue that this practice can help offset Earth's rising carbon dioxide levels.
November 4, 2013
Diatom algae populations tell a story about climate change in Greenland
Researchers try to determine how much this "canary in a coal mine" can say about the impact of a warming climate on the Arctic region
With support from the National Science Foundation (NSF), lake ecologist Jasmine Saros and her team from the University of Maine are plying the lake waters of southwestern Greenland, gathering samples of "diatoms" to study how climate change is affecting this Arctic ecosystem. Diatoms are a type of algae that responds rapidly to environmental change and leaves a fossil in lake sediments.
Striking changes in communities of diatoms have occurred over the last 150 years. Diatom species generally associated with warmer conditions are increasing at unprecedented rates in the sediment record.
However, changes in diatom assemblages in lake sediments from west Greenland are different from those in the rest of the Arctic in that they are already rich in these 'warmer' water diatoms throughout the Holocene (the last 11,700 years of geologic time). This difference has raised questions about what diatoms can tell us about environmental change in the Arctic, and suggests the need to clarify the ecological traits of diatoms in order to advance our understanding of drivers of change.
Recent research in alpine regions reveals that key diatom species that are used as indicators of 20th century warming in both arctic and alpine lakes respond specifically to both climate-induced changes in energy (mixing depths) and mass inputs (nutrients) to lake ecosystems. This suggests that spatially- and temporally-variable interactions between climate-induced changes in the physical and chemical structure of lakes may drive diatom community changes, but this is currently untested in arctic lakes.
This research couples comparative lake sampling with both small- and large-scale experiments to provide key ecological information that will enable interpretation of climate-induced ecological changes from several existing diatom records from southwest Greenland. The objective of this project is to determine the effects of climate-driven changes in nutrients and water column stability on the relative abundances of key diatom species, and to apply that information to existing diatom records to determine climate-induced changes in these lake ecosystems.
The research in this episode was supported by NSF award #1203434, an Arctic System Science program award for "Deciphering the ecology of key diatom taxa to understand climate-induced changes in West Greenland lakes."
Any opinions, findings, conclusions or recommendations presented in this material are only those of the presenter grantee/researcher, author, or agency employee; and do not necessarily reflect the views of the National Science Foundation.