Climate change is having a dramatic affect on the oceans -- rising sea levels, warming temperatures, increased acidity -- all of which will take its toll on sea life. The clownfish will have a particularly hard time surviving, as scientists have discovered that rising CO2 levels in the oceans alter their sense of smell, preventing them from evading predators and finding shelter.
Researchers at James Cook University simulated CO2 levels within the range predicted for the end of the century with clownfish larvae. The experiments tested their behavior at increasing concentrations. At 550 ppm of CO2, the current concentration, larvae were able to detect a predator and swim in the opposite direction, but as the concentrations rose to 700 ppm, only half the larvae swam away, with the other half swimming toward a predator.
At the highest concentration, 850 ppm, their sense of smell was completely askew and all larvae swam toward the predator.
The same researchers carried out experiments last year that showed that rising CO2 levels also prevented baby clownfish from being able to find their way home.
The researchers think that the CO2 could be affecting the fishes' neurons and confusing how they perceive threats and interpret smells and that other fish will likely be similarly affected.
written by environmental services, July 08, 2010
written by Alice, July 12, 2010
|< Prev||Next >|