Greenpeace Foundation
But We’re Changing the Seas.
And we may not have thousands of years, or even hundreds.
Although land creatures, we are very clever when it comes to intentionally killing things in the sea. And we have not cared much when it happens as a by-product of something else we feel like doing.
Most large sea creatures are gone now, having disappeared within the last 60 years. Many which formerly existed in large populations survive only in small remnant groups and in remote areas. Many more are extinct, and that list grows daily.
Our fisheries have overwhelmed natural systems. Nearly all fisheries are entirely depleted or heavily overfished. We’ve wiped out most of the world’s sharks due to a high-priced market in sharkfin soup. Sea turtles are relatively few and far between. Marine mammals like whales, seals, and dolphins are stressed and fragmented populations. We’ve destroyed bottom reef communities with trawling which leaves the sea bottom looking like the lifeless surface of the moon.
We based our fishing activities on money, not nutrition, and there is no inherent limit to how much money a corporation wants. This leads to a “tragedy of the commons” situation, in which fisheries respond to declining catches by fishing ever harder, with more technology, to catch the last fish before someone else does.
Yet the devastation of marine resources was only the first act. We’re now changing the seas in ways which will make them unable to support the sorts of sea life we have depended on, even in principle.
Species are Disappearing Forever
Marine species are already being lost at a “mass extinction” speed, just due to our unrestrained fishing, pollution, and impact of marine habitat.
But now the very chemistry of the seas is being radically changed by the human “carbon pulse”.
Humans have at most a couple centuries worth of oil and coal. We’ve burned through a fair bit of it, and are burning more every year. This “fossil fuel” era will be brief in historic terms. Disasters usually are.
We haven’t appreciated it until recently, but “global warming” isn’t the worst aspect of pumping gigatons of CO2 into the atmosphere. Because decades before it converts rainforest to stubble and farmland to deserts, it will take something vital away from sea life: calcium carbonate skeletons.
This has happened before from time to time in the last billion years, and when it does it isn’t pretty. All animal life which precipitates calcium carbonate to live – coral, plankton, shellfish, a huge percentage of sea life – must get by without it, because with enough CO2 the oceans acidify, and calcium carbonate can’t exist in them.
It’s already happening at high latitudes. Pteropods – known as sea butterflies – a large part of the base of the ocean food chain – are dissolving. They are only the first.
It’s simple chemistry. Everyone knows someone who disbelieves the scientific consensus on global CO2 heating, if they live in the USA. (Because of course dentists and taxi drivers understand planetary science better than NASA does, right?) But there’s nothing to argue about with the simple chemistry of acidification, unless you don’t believe in cola. Put a calcium carbonate antacid into a glass of cola and see what happens. It’s a physical fact: past certain concentrations of CO2 in the atmosphere, acidification of the seas past crucial threshold is inevitable.
And that isn’t just bad news for critters with shells, because all life depends on food webs which depend on tiny simple creatures. If you knock them out of the food chain, you get food webs which no longer support the larger creatures at higher trophic levels.
So just at the time we are “harvesting” sea life far past its ability to rebound, we are setting the stage to end it entirely. This will be locked into inevitability with only several more decades of carbon-burning-as-usual.