SOURCE:
BBC News Online: http://news.bbc.co.uk/1/hi/sci/tech/4806146.stm
Article by: Rebecca Morelle, BBC News Science Reporter

2) Warming Waters Will Disrupt Ocean Food Chains

Warming ocean temperatures could cause drastic shifts in populations of the tiny plants that are the foundation of many ocean food chains, according to a new Dutch study published in the journal Nature. At issue are deep-water bands of phytoplankton, often found in tropical and subtropical oceans at depths that balance access to sunlight and to nutrients from deeper waters. Fish, seabirds and other organisms feed on the microscopic plants, whose populations are considered relatively stable, with minor seasonal variations based on available light. But climate modeling by researchers at the University of Amsterdam suggests that calmer ocean currents--which are predicted as waters warm—could change the location and timing of plankton blooms, with unknown consequences for ocean food chains. The effect is noticeable at "the lower end of the realistic range" of predicted ocean warming, the authors note.

SOURCE:
Lauren Morello, E&E News PM, 19 January 2006.

REFERENCE:
Jef Huisman, Nga N. Pham Thi, David M. Karl and Ben Sommeijer: Reduced mixing generates oscillations and chaos in the oceanic deep chlorophyll maximum. Nature 439 (7074):322; 19 January 2006; http://www.nature.org

3) Increasing Acidity of Oceans Could Cause Mass Extinction

Increased carbon dioxide emissions are rapidly making the world's oceans more acidic and, if unabated, could cause a mass extinction of marine life similar to one that occurred 65 million years ago when the dinosaurs disappeared. Author Ken Caldeira wrote, in a report delivered at the meeting of the Ocean Sciences Meeting in February, "The next centuries may bring changes in ocean carbonate mineral saturation states that have not been experienced in for several tens of millions of years."

For this report and others from the 2006 Ocean Sciences Meeting, go to: http://www.agu.org/meetings/os06/

REFERENCE:
Caldeira, K: Carbon Dioxide and Ocean Chemistry Change: What Does the Geologic Record Tell Us About the Future? Eos Trans. AGU, 87(36), 2006. Ocean Sciences Meeting Supplement, Abstract OS14B-06.

Related News:

A study published in the Letters section of the journal Nature reports that rivers are delivering increasing amounts of fresh water to the ocean. The cause seems to be decreased evaporation caused by higher concentrations of atmospheric carbon dioxide, which cause plants to close their stomata (surface pores).

For more, go to: http://www.nature.com/nature/journal/v439/n7078/full/439793a.html

REFERENCE:
N. Gedney, P.M. Cox, R.A. Betts, O. Boucher, C. Huntingford, and P.A. Stott: Detection of a direct carbon dioxide effect in continental river runoff records. Nature 439:835-838, 16 February 2006.

4) Greenland's Icebergs Melting Two Times Faster Than Thought

Greenland's glaciers are melting into the sea twice as fast as previously believed, says a new report published in the journal Science. The Greenland data are mirrored by findings from Bolivia to the Himalayas, scientists said, noting that sea-level rise threatens widespread flooding and severe storm damage in low-lying areas worldwide. The scientists said they did not understand the mechanism causing glaciers to flow and melt more rapidly, but they said the changes in Greenland were unambiguous--and accelerating: In 1996, the amount of water produced by melting ice in Greenland was about 90 times the amount consumed by Los Angeles in a year. Last year, the melted ice amounted to 225 times the volume of water that Los Angeles uses annually. While sea-level increases of a few feet may not sound like much, they could have profound consequences on flood-prone countries such as Bangladesh and trigger severe weather around the world. The study also highlights how seemingly small changes in temperature can have massive effects.

To read the full report, go to:

http://www.sciencemag.org/content/vol311/issue5763/index.dtl

SOURCE:
Shankar Vedantam: Glacial-melt rate quickens, accelerating sea changes. The Washington Post, 17 February 2006. http://seattletimes.nwsource.com/html/nationworld/2002810749_glacier17.html

REFERENCE:
Rignot and Pannir Kanagaratnam: Changes in the Velocity Structure of the Greenland Ice Sheet. Science 311: 986-990, 17 February 2006. DOI: 10.1126/science.1121381].

5) Climate Change Leading to Parasite-Induced Collapse of Amphipod Populations, Says Study

The coastal mud-shrimp Corophium volutator is widespread in coastal soft-bottom habitats on both sides of the North Atlantic, with densities often approaching 100,000 individuals per square meter. However, according to a recent study in the journal Oecologia, such dense populations are at risk because of the effects of climate change.

According to the study, by Kim Mouritsen of the University of Aaarhus in Denmark and colleagues, due to its abundance and burying activity, C. volutator “significantly alters the stability of coastal sediments, influencing benthic community structure ....” It also functions as secondary intermediate host for a number of trematode parasites that in European waters use the mud-snail Hydrobia ulvae as first intermediate host and shorebirds as definitive hosts. Mouritsen and colleagues note that, “The system appears very sensitive to climatic fluctuations, because the transmission rates of larval parasites from snails to amphipods and the rate of parasite-induced amphipod mortality are strong positive functions of temperature. Hence, under a climate warming scenario the population of C. volutator is likely to decline.”

Indeed, modeling by the study’s authors showed that at an increase of 3.8 degrees C—the level predicted for the Wadden Sea by 2075—the modeled amphipod population barely escaped extinction; and for greater increases, the population became extinct. “The most realistic model we can construct using the best available data predicts that it is not a matter of whether dense populations of C. volutator will crash due to parasite effects, in the face of increasing temperatures, but when,” they write.

They conclude: “C. volutator is unlikely to disappear entirely from the Wadden Sea region. Rather, dense assemblages of the amphipods may tend to disappear along with a general population decline as temperatures are rising. This scenario may have important ecological ramifications due not only to the amphipod’s importance as prey for benthic invertebrates, fish and birds, but also to their stabilizing effect on non-cohesive sediments. The disappearance of such amphipod beds will result in significant sea-bed erosion and, in turn, structural changes to the benthic animal and microflora community.”

SOURCE:
Mouritsen, K.N., et al. 2005. Climate warming may cause a parasite-induced collapse in coastal
amphipod populations. Oecologia 146: 476–483

For more information, go to: http://seaweb.org/secure/newsletter-ocean-update.php#Vol11No3_2

6) Setting High Standards: EE Builds a Home in Teacher Education Accreditation

The article features the work being done by the North American Association for Environmental Education to have environmental education incorporated into the accreditation of teacher preparation programs. It’s the first in a series of articles that the Environmental Education and Training Partnership has commissioned on current work in environmental education.

For the full report, go to: http://eetap.org/media/pdf/accreditation.pdf

SOURCE:
Environmental Education and Training Partnership. Article by Michele Archie.