Ocean Fish in Trouble

Most of the carbon dioxide (CO2) associated with human activity is absorbed by the oceans, which act as a huge carbon sink. In doing so, the oceans help curb global warming by keeping greenhouse gases from trapping heat in the atmosphere but on the downside, CO2 and seawater react to form carbonic acid — which makes the water more acidic.

Among the many potential problems this causes to marine life, a new study found that the increasingly acidic oceans are making fish lose their sense of smell.

Since the Industrial Revolution in the 18th century, oceanic CO2 has risen by 43% and, by the end of the century, scientists predict it will grow by another 250%.

Take us humans, for instance, whose normal blood pH ranges between 7.35 and 7.45. Just a slight drop in blood pH of 0.2-0.3 can cause seizures, comas, and even death.

For some creatures, increasing ocean acidity is worse than in others. Because of lower pH of seawater, carbonate ions bind together, making them less readily available for corals, oysters, mussels, and many other shelled organisms that need them to build shells and skeletons. What’s more, ocean acidification causes coral bleaching by expelling the symbiotic algae living in their tissue, turning them white and subject to mortality.

ZME Science- July 2018

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