How Ocean Acidification Could Endanger Hundreds of Marine Species

Scientists are warning that ocean acidification is impacting microorganisms in our ocean known as phytoplankton and, as they pay a key role in ocean habitats, any future loss or change in species numbers could impact marine life in a big way.

Ocean acidification isn’t always mentioned in conjunction with phytoplankton blooms, and the U.S. Government has been slow to link the two, but MIT researchers say acidification of our oceans could impact phytoplankton in a big way, and that will be bad news for our marine life.

Publishing in the journal Nature Climate Change, the scientists say their research shows that ocean acidification–where our oceans absorb gasses like carbon dioxide and sulphor dioxide that are released during the burning of fossil fuels–will increase to such an extent that by 2100 several species of phytoplankton will die out, robbing several larger marine species of a vital food source, while other phytoplankton species will rapidly increase in number, threatening the delicate balance of marine habitats and even potentially threatening the bird populations that depend on marine life.

According to the National Ocean Service (NOAA), phytoplankton are organisms that function in much the same way as the plants we see around us. They contain chlorophyl and depend on sunlight. For that reason they tend to float close to the surface of the water where they can get as much sunlight as possible. They also take in nutrients like nitrates, phosphates and sulfur.

In marine environments phytoplankton play a key role and are a food source for a number of species, from tiny animals like shrimp and snails, all the way up to jellyfish and even whales. 

Stephanie Dutkiewiczprincipal, research scientist at MIT’s Center for Global Change Science and lead author in this most recent study, suggests that while a suspected link between increased acidification and an effect on phytoplankton isn’t new, the researchers in this study found that the effect was more pronounced than other estimates had suggested, and that in turn could impact wider species numbers more heavily than had been estimated.

“I’ve always been a total believer in climate change, and I try not to be an alarmist, because it’s not good for anyone,” Dutkiewicz is quoted as saying. “But I was actually quite shocked by the results. The fact that there are so many different possible changes, that different phytoplankton respond differently, means there might be some quite traumatic changes in the communities over the course of the 21st century. A whole rearrangement of the communities means something to both the food web further up, but also for things like cycling of carbon.”

Taking a broad overview of the research, with more detail available here for those looking to read in-depth, the researchers looked at 96 species of phytoplankton in total. Using an environmental model, which is designed to account for details like ocean currents, temperature and salinity, as well as a model that is designed to approximate how the species of phytoplankton will behave, the researchers found that as acidification levels rose, several species were able to out-compete others in a dramatic way. Over normal evolutionary time this wouldn’t be that concerning but, because it could happen so rapidly, it could leave larger marine species who rely on the out-competed phytoplankton in a state of severe food shortage. Also, the overabundance of other species could alter the food chain in other ways, making larger marine species that feed on those phytoplankton blooms also increase in number, further throwing out the eco-system balance.

What also became apparent through this study was that the phytoplankton are likely to move toward the poles to escape rising sea temperatures. This phenomena is of course expected from other marine life, and the phytoplankton’s movement will bring about similar problems, such as invasive species wiping out native ones, as well leaving those animals that do not migrate short of food.

“If you went to Boston Harbor and pulled up a cup of water and looked under a microscope, you’d see very different species later on,” Dutkiewicz remarks. “By 2100, you’d see ones that were living maybe closer to North Carolina now, up near Boston.”

As above, this isn’t the first time that scientists have highlighted ocean acidification as a problem. We already know that it stands to radically alter a number of marine habits and in particular coral reefs, however this research is quite stark in its findings. It’s also among the first research to say that all phytoplankton species could be affected and not just those that depend on calcium carbonate shells that acidification will weaken and even destroy.

As such, this research is eye-opening and is perhaps one of the starkest reminders that even what might seem like small changes to our marine ecosystems, like the profile of phytoplankton blooms, could have a big impact on the diversity and even density of our marine habitats. Reducing acidifcation through reducing overall greenhouse gasses is therefore a must if we want to preserve the delicate balance of life in our oceans.

Photo credit: Thinkstock.


Mark Donner
Mark Donner2 years ago

I have to repeat this fact from an earlier comment: "They (mega corporations) prefer sociopathic politicians that are not too bright and will do anything they want them to". Most of these global corporations fit the definition of terrorists in every way.

Siyus Copetallus
Siyus Copetallus2 years ago

Thank you for sharing!

Paulinha Russell
Paulinha Russell2 years ago

Thank you

Carole R.
Carole R2 years ago

Very frightening and sad.

Teresa W.
Teresa W2 years ago


Deborah W.
Deborah W2 years ago

Did you really say COULD?

Even SMALL CHANGES to our marine ecosystems DO have a big impact on the diversity and density of our marine habitats. Be nice to try correcting a specific before it too becomes another one of those BIG CHANGES now out of hand.

Herein lies the rub ... "if we want to preserve the delicate balance of life in our oceans" ... do we? Seems no one really gives a shit, at least long-term ... just another raised then lowered idea among the many others unaddressed

Melania Padilla
Melania P2 years ago

Ocean acidification is a very serious issue; we're putting in risk thousands of species living in the oceans and ultimately, us.

Karen H.
Karen H2 years ago

Tony L, I don’t think governments are too lily-livered to do anything. I think the majority of politicians are prostituting themselves to the polluters. Give me money, I’ll vote in favor of your corporation, and I’ll deny climate change.

Tony L - AWAY
Away L2 years ago

Polluters should be made to pay. Sadly the governments are too lily-livered to stand up to the big corporations... or the low tax culture makes the governments too weak to stand up to the powerful corps.

Amy Thompson
Amy Thompson2 years ago

More shocking revelations showing the damage our earth is suffering. I wish more would stop the blatant disregard for the planet that the majority of the population seems to practice.