We often hear about the dangers to our familiar environment on land caused by rising CO2 emissions but much less about potentially catastrophic changes to our oceans. The changes to the chemistry of the oceans – known as ocean acidification – threatens us as well as everything that lives in the sea.
Oceans have absorbed about a third of all the CO2 produced by human activities, and as CO2 levels have risen, seawater has become more acidic. If we keep growing CO2 emissions, by the end of the century the oceans will be more than twice as acidic as they were in pre-industrial times.
The rate of change to the acidity of the oceans is the fastest for the millions of years. More acidic seas make it more difficult for shellfish to construct and maintain their shells. Corals, sea urchins and a number of other species will also struggle to adjust.
More acidic seas will also negatively affect the behaviour of some fish species and will likely disrupt complex food webs with implications for species ranging from microscopic algae – that provide half the world’s oxygen – right through to top predators such as sharks, marine mammals and seabirds.
Forest & Bird produced this report because we believe New Zealanders need to be aware of the dangers posed by ocean acidification and warming seas to marine life, as well as our economy and wellbeing. The report highlights the only sure way to avoid the worst impacts of ocean acidification is to urgently cut CO2 emissions.
Click on the link below to see the report and find out more about what we know about ocean acidification, what we need to learn and what we need to do.