(Here it is: Tuesday. Which is sort of like Monday. And therefore time, once again, for Science News & Wisdom from the esteemed Dr. Possum. Said News & Wisdom appearing here every Monday. Or on some day like a Monday.)
The time has arrived one more time. Time for more science talk. New discoveries, new takes on old knowledge, and other bits of news are all available for the perusing in today’s information world. Over the fold are selections from the past week from a few of the many excellent science news sites around the world. Today’s tidbits include carbon dioxide is driving fish ‘crazy’, harp seals on thin ice, most distant dwarf galaxy detected, genetic analysis shows tortoise species thought to be long extinct to be alive today, and the first physical evidence of tobacco in a Mayan container. Pull up that comfy chair and grab a spot near the fireside. There is always plenty of room for everyone. Another session of Dr. Possum’s science education, entertainment, and potluck discussion is set to begin.
Rising carbon dioxide concentrations from human activity may be damaging the central nervous systems of fish and endangering their ability to survive the future.
Prof. Munday and his colleagues began by studying how baby clown and damsel fishes performed alongside their predators in CO2-enriched water. They found that, while the predators were somewhat affected, the baby fish suffered much higher rates of attrition.
“Our early work showed that the sense of smell of baby fish was harmed by higher CO2 in the water—meaning they found it harder to locate a reef to settle on or detect the warning smell of a predator fish. But we suspected there was much more to it than the loss of ability to smell.”
The team then examined whether fishes’ sense of hearing—used to locate and home in on reefs at night, and avoid them during the day—was affected. “The answer is, yes it was. They were confused and no longer avoided reef sounds during the day. Being attracted to reefs during daylight would make them easy meat for predators.”
Other work showed the fish also tended to lose their natural instinct to turn left or right—an important factor in schooling behaviour which also makes them more vulnerable, as lone fish are easily eaten by predators.