New study up-ends conventional wisdom
Phytoplankton—tiny, photosynthetic organisms—are essential to life on Earth, supplying us with roughly half the oxygen we breathe. Like all other life forms, phytoplankton require the element phosphorus to carry out critical cellular activity, but in some parts of the world’s ocean, P is in limited supply. How do phytoplankton survive when phosphorus is difficult to find? (more…)
Gewässertyp des Jahres 2014: Der tiefe nährstoffarme See Norddeutschlands
Über die Hälfte der tiefen und nährstoffarmen Seen Norddeutschlands sind in einem guten ökologischen Zustand und erfüllen damit bereits heute die Ziele der EU-Wasserrahmenrichtlinie. Fast alle Seen dieses Typs sind frei von Schadstoffen und weisen daher einen guten chemischen Zustand auf. Sie eignen sich hervorragend zum Baden und Tauchen. Bekannte Seen dieses Typs sind der Große Stechlinsee und der Wandlitzsee in Brandenburg sowie der Plöner See in Schleswig-Holstein. Aufgrund dieser guten Bewertung kürt das Umweltbundesamt anlässlich des Internationalen Tag des Wassers den „tiefen, nährstoffarmen See Norddeutschlands“ zum „Gewässertyp des Jahres“ 2014. Er kommt im Norddeutschen Tiefland, östlich der Elbe in Sachsen-Anhalt, Brandenburg, Mecklenburg-Vorpommern und Schleswig-Holstein vor. (more…)
The phrase, ‘Eat your vitamins,’ applies to marine animals just like humans. Many vitamins are elusive in the ocean environment.
University of Washington researchers used new tools to measure and track B-12 vitamins in the ocean. Once believed to be manufactured only by marine bacteria, the new results show that a whole different class of organism, archaea, can supply this essential vitamin. The results were presented Feb. 24 at the Ocean Sciences meeting in Honolulu. (more…)
ANN ARBOR — Declines of the food resources that feed lake organisms are likely causing dramatic changes in the Great Lakes, according to a new study.
The study, led by the U.S. Geological Survey and co-authored by three University of Michigan researchers, found that since 1998, water clarity has been increasing in most Great Lakes, while phytoplankton (the microscopic water organisms that feed all other animals), native invertebrates and prey fish have been declining. These food web changes fundamentally affect the ecosystem’s valuable resources and are likely caused by decreasing levels of lake nutrients, and by growing numbers of invasive species such as zebra and quagga mussels. (more…)
At the end of the last Ice Age, as the world began to warm, a swath of the North Pacific Ocean came to life. During a brief pulse of biological productivity 14,000 years ago, this stretch of the sea teemed with phytoplankton, amoeba-like foraminifera and other tiny creatures, who thrived in large numbers until the productivity ended—as mysteriously as it began—just a few hundred years later.
Researchers have hypothesized that iron sparked this surge of ocean life, but a new study led by Woods Hole Oceanographic Institution (WHOI) scientists and colleagues at the University of Bristol (UK), the University of Bergen (Norway), Williams College and the Lamont Doherty Earth Observatory of Columbia University suggests iron may not have played an important role after all, at least in some settings. The study, published in the journal Nature Geoscience, determines that a different mechanism—a transient “perfect storm” of nutrients and light—spurred life in the post-Ice Age Pacific. Its findings resolve conflicting ideas about the relationship between iron and biological productivity during this time period in the North Pacific—with potential implications for geo-engineering efforts to curb climate change by seeding the ocean with iron. (more…)
Combined research efforts by scientists involved in the Gulf of Maine Toxicity (GOMTOX) project, funded by NOAA’s Ecology and Oceanography of Harmful Algal Blooms (ECOHAB) program, and administered by the National Centers for Coastal Ocean Science (NCCOS), have led to enhanced understanding of toxic algal blooms on Georges Bank. This new information, coupled with an at-sea and dockside testing protocol developed through collaboration between GOMTOX and U.S. Food and Drug Administration (FDA) investigators, has allowed fishermen to harvest ocean quahogs and surf clams in these offshore waters for the first time in more than two decades.
The shellfish industry estimates the Georges Bank fishery can produce up to 1 million bushels of surf clams and ocean quahogs a year, valued $10 – 15 million annually. “There is a billion dollars’ worth of shellfish product on Georges Bank that is property of the United States but that can’t be harvested because of the threat of toxicity, and 99.9% of the time, it is good wholesome product,” says Dave Wallace of North Atlantic Clam Association and a GOMTOX participant. “In an unusual and unique partnership, we worked with GOMTOX scientists, the FDA, and the states of Massachusetts, Rhode Island, New Jersey and Delaware and now that huge resource can go into commerce, which helps the entire country.” (more…)
All living organisms rely on iron as an essential nutrient. In the ocean, iron’s abundance or scarcity means all the difference as it fuels the growth of plankton, the base of the ocean’s food web.
A new study by biogeochemists and glaciologists at Woods Hole Oceanographic Institution (WHOI) identifies a unexpectedly large source of iron to the North Atlantic – meltwater from glaciers and ice sheets, which may stimulate plankton growth during spring and summer. This source is likely to increase as melting of the Greenland ice sheet escalates under a warming climate. (more…)
Cheating is a behavior not limited to humans, animals and plants. Even microscopically small, single-celled algae do it, a team of UA researchers has discovered.
Humans do it, chimpanzees do it, cuckoos do it – cheating to score a free ride is a well-documented behavior by many animals, even plants. But microscopically small, single-celled algae? Yes, they do it too, biologists with the University of Arizona’s department of ecology and evolutionary biology have discovered.
“There are cheaters out there that we didn’t know of,” said William Driscoll, lead author of a research report on the topic who studied an environmentally devastating toxic alga that is invading U.S. waters as part of his doctoral research in the lab of Jeremiah Hackett, an assistant professor of ecology and evolutionary biology. (more…)
