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Las tuberías que transportan petróleo crudo a puertos en Columbia Británica pueden significar malas noticias para el salmón, según un nuevo estudio liderado por la Universidad de Guelph. La exposición a un producto de arenas bituminosas (betún diluido) que deteriora la capacidad para nadar y cambia las estructuras del corazón de los salmones jóvenes. La investigación será publicada en la revista Environmental Toxicology and Chemistry, y está disponible en línea.

There was a period during the last ice age when temperatures in the Northern Hemisphere went on a rollercoaster ride, plummeting and then rising again every 1,500 years or so. Those abrupt climate changes wreaked havoc on ecosystems, but their cause has been something of a mystery. New evidence published this week in the leading journal Science shows for the first time that the ocean's overturning circulation slowed during every one of those temperature plunges - at times almost stopping.

"People have long supposed this link between overturning circulation and these abrupt climate events. This evidence implicates the ocean," said L. Gene Henry, the lead author of the study and a graduate student at Columbia University's Lamont-Doherty Earth Observatory.

Engineers at Oregon State University have created a new computer modeling package that people anywhere in the world could use to assess the potential of a stream for small-scale, “run of river” hydropower, an option to produce electricity that’s of special importance in the developing world.

The system is easy to use; does not require data that is often unavailable in foreign countries or remote locations; and can consider hydropower potential not only now, but in the future as projected changes in climate and stream runoff occur.

Scientists at MIT and elsewhere have identified the "first fingerprints of healing" of the Antarctic ozone layer, published today in the journal Science.

The team found that the September ozone hole has shrunk by more than 4 million square kilometers -- about half the area of the contiguous United States -- since 2000, when ozone depletion was at its peak. The team also showed for the first time that this recovery has slowed somewhat at times, due to the effects of volcanic eruptions from year to year. Overall, however, the ozone hole appears to be on a healing path.

The authors used "fingerprints" of the ozone changes with season and altitude to attribute the ozone's recovery to the continuing decline of atmospheric chlorine originating from chlorofluorocarbons (CFCs). These chemical compounds were once emitted by dry cleaning processes, old refrigerators, and aerosols such as hairspray. In 1987, virtually every country in the world signed on to the Montreal Protocol in a concerted effort to ban the use of CFCs and repair the ozone hole.

Climate change is already affecting inland fish across North America -- including some fish that are popular with anglers. Scientists are seeing a variety of changes in how inland fish reproduce, grow and where they can live, according to four new studies published today in a special issue of Fisheries magazine.

Fish that have the most documented risk include those living in arid environments and coldwater species such as sockeye salmon, lake trout, walleye, and prey fish that larger species depend on for food.

Climate change can cause suboptimal habitat for some fish; warmer water, for example, can stress coldwater fish. When stressed, fish tend to eat less and grow less. For other fish, climate change is creating more suitable habitat; smallmouth bass populations, for example, are expanding.