Do you ever use a sponge? Of course you have. It absorbs liquids as we clean things the way we like them. The oceans absorb chemicals in a similar way peculiarly carbon dioxide.
CO2 absorption by the oceans is a natural part of the carbon cycle of our planet. When CO2 is absorbed by the oceans it changes their PH making it more acid. Given the huge amounts of carbon human activities have put into the atmosphere since the start of the industrial revolution it only follows that the oceans have absorbed more of it. The oceans of our planet have absorbed one-third of the CO2 we have produced from our activities. With the concomitant increase in the PH what are the changes we’re currently seeing and what will happen in the future unless we stop making the oceans more acidic?
Shellfish like oysters, clams and snails form their shells from calcium carbonate (CaCO3). Making the oceans more acidic has a direct effect on their shell formation. This affects them in all stages of the life cycle from larvae through adult. The oyster larvae start forming their shells while they are still in the water column. This was documented in an oyster hatchery in Tilamook, Oregon which piped in Pacific ocean water for use it the hatchery. The increase in acidity of the ocean water used in the hatchery was found to be the cause. The effects of increased acidity are being seen all over the global in places like Australia, Seattle – Washington, Los Angles – California and Maryland.
The commercial implications are obvious. There will first be and increase in the variability of shellfish with an associated rise in prices. Then the seafood brokers will turn to the hatcheries to make up for the shortfall in natural production and will find they have the same problems. That person we all know will feel that this doesn’t affect him but what he doesn’t understand or chooses to ignore is that there are many of species in the world that eat shellfish besides humans. Bivalves provide a significant link in the food chain, one thing eats another and so on, and with their reduction or loss many or species will be impacted. As examples, the impact of this will affect species like the sea otters which eat abalone, many filter fish which eat the oyster larvae and the base of the food chain plankton.
How fast is this happening? It’s like watching grass grow. Stare at it all day and you won’t see any change, take a picture of the grass once a week for two months and you’ll see significant change. If you ignore it you’ll have trouble finding your yard furniture in a couple of years.
The acidification of the oceans in the coming decades will have a profound impact on how we look at the oceans.
If you’d like a good primer on ocean acidification the following video puts in terms that everyone should find understandable .
Think Global – Act Local!