Environment

Microbial symbionts live in the guts of animals, the interiors of corals, and the roots of plants. They help plants take up nutrients and help cows break down cellulose, but they can also be harmful to their hosts. Stan Faeth wants to understand the relationship between symbionts, their hosts, and their role in everything from conservation to cancer cures. --by Margaret Coulombe

Historians aren't known for interdisciplinary collaborations. But Paul Hirt is getting environmental historians out into the field and working with anthropologists, ecologists and geographers. He hopes to increase their understanding of the complex interactions between humans and the landscape. --by Adelheid Fischer

The sky islands borderlands of the Southwest is a unique area harboring such a broad range of life that Conservation International has designated it a hotspot of global diversity. Once sparsely settled, the sky islands borderlands are now undergoing economic, ecological, and social upheavals. Environmental historian Paul Hirt is looking at the region's past to help citizens, businesses and governments manage its present and future. --by Adelheid Fischer

Nitrogen pollution from agricultural and urban runoff is a serious threat to ocean ecosystems. Nitrogen, in the form of nitrates, could generate algal blooms, create oceanic "dead zones" and kill coral, fish and shellfish in coastal zones. Researchers have discovered that small organisms in streams and rivers can filter out excess nitrogen before it reaches the oceans. However, overloading streams with too many nitrates reduces their filtering ability. --by Margaret Coulombe

To humans, trichloroethene (TCE) is a dangerous pollutant, one that recently forced two Phoenix-area municipalities to shut down their water supplies. But to a group of bacteria called dehalogenerators, TCE is like oxygen. These microorganisms take in TCE and remove the chlorine, leaving harmless ethene behind. Now a team of scientists has developed a specialized water treatment system that employs the bacteria to make water supplies safer. --by Joe Caspermeyer

Imagine a planet where everyone and everything is named Bob. Things would get confusing pretty fast! The "unbelievably sexy" Hugh Downs narrates this laugh-out-loud video explaining the nature of taxonomy--the system for naming and classifying species--and why it's important.

When you visit the beach, the ocean always looks the same--but that doesn't mean it isn't changing. A new study has taken a comprehensive look at human impacts on marine ecosystems, including coral reefs, estuaries, and pelagic waters. The results show that none of Earth's oceans have escaped human influence. Now, oceanic maps from the study can help policy makers determine where human activities are most likely to cause negative effects. (Read the full story) --by Margaret Coulombe

Researchers have cracked the genetic code of a bacterium that harvests far-red light by making a rare form of chlorophyll (chlorophyll d). The bacterium, Acaryochloris marina, uses light from a part of the spectrum that few other organisms can use. Understanding how it works could help drive advances in agriculture and bioenergy. --by Skip Derra

The majority of people on Earth will soon live in megacities--urban areas with populations of 10 million or more. What will these future cities look like? And how will their populations meet the unique environmental challenges of the megacity? --by Margaret Coulombe

ASU researchers are using bacteria and sunlight to generate hydrogen, a clean fuel that produces no greenhouse gases. The biohydrogen project aims to harness the energy in sunlight using microbial photosynthesis to produce hydrogen. --by Skip Derra