The world’s oceans face multiple threats, explains Carl Zimmer for Discover. “That extra carbon (9.2 billion tons in 2009 alone) is acidifying the ocean, warming it, and possibly even stripping it of oxygen,” he writes.
The ocean’s pH levels slowly drop as it struggles to absorb more of the carbon pumped into the atmosphere. Joe, captain of F/V St Jude, was a mathematician before heading out to sea. The pH scale is a logarithmic scale. Logarithms are shorthand for exponents – as in exponential growth. A small change of one level is magnified 10 times. The changes we see in communities and habitats take place at a faster and faster pace. Migrating species are especially hard hit. We see it with some species of tuna – like the blue-fin Atlantic. And we see it at the bird feeder.
For years, in June, a friend in Connecticut would report with joy how an indigo bunting couple would stop by the feeder, staying just a week or two before moving on to Canada. The brilliant birds have a lifespan of about 4 to 11 years, but their offspring follow the path in travels from South America to Canada.
The buntings have not been seen in recent years.
Another study suggests that some species of fish will head to cooler waters as the ocean temperatures warm and habitats change, explains John Timmer for Arstechnica.com.
Photo of indigo bunting courtesy of hart_curt and Wikimedia Commons.