Most of the news about climate change is about how it affects the atmosphere and land creatures. But we shouldn’t forget the source of life that covers nearly three-quarters of Earth’s surface: the ocean. About a quarter to a third of all carbon dioxide emissions from our cars and factories are absorbed by the Earth’s oceans. Much of it becomes “fixed” and stored in ocean plants like seagrass. Ocean plants absorb carbon just like forests and field grasses do. But, any of the CO2 that is not fixed dissolves into the seawater, altering the chemistry of the waters. The result is ocean acidification.
Over the past 250 years, ocean acidity has increased by 30 percent as oceans absorbed around 530 billion tons of carbon dioxide. (That’s the equivalent of 500 years of CO2 emissions produced in the U.S. at current levels.) The change in pH has troubled researchers in the recent years, as they predict ocean acidity will more than double by 2100 if fossil fuels are burned at today’s rate. The polar regions will be the first to undergo the most dramatic changes, and scientists forecast that the Southern Ocean has the potential to become corrosive with radically lowered pH levels by 2050.
However, species with shells, such as oysters, lobsters and mussels, will be particularly disrupted. And, we are already seeing harm from sudden changes in pH that coincide with seasonal upwhellings in the Pacific Northwest. In these instances, the more corrosive waters start to dissolve the shells of juveniles of various shellfish before they can mature. In Oregon, for example, researchers found that a decreased larval oyster population has already resulted from ocean acidification. The population has dropped to the point that the hatchery owners have determined that the harvested oysters may not longer be economically viable.
Similarly, researchers predict that the dissolving of coral reefs due to our changing the ocean’s chemistry may lead to their extinction in 50 years. Coral reefs are the home for many ocean creatures. The destruction of these reefs, combined with the loss of shellfish would, in turn, affect the entire marine food web.
You may be thinking, “But I don’t even like seafood!” or “I don’t even live near the ocean. How does this affect me?” Believe it or not, all of us have some contact with the ocean, even if we have never even seen it. We rely on the ocean for tourism, fishing, and natural resources such as salt and kelp. The benefits that we derive from the ocean are known as ecosystem services. Remarkably, about one-fifth of the world’s population relies on seafood as their source of protein (yes, nearly 1.5 billion people!). Coastal regions rely heavily on the fishing and harvesting industries. Mollusk sales, for example, make around $750 million per year and account for about 20 percent of total U.S. fisheries revenue. Mollusk harvests are expected to drop 10 to 25 percent in the next 50 years, which would decrease their sales by $75 to $187 million dollars per year if we continue down our current path.
Ultimately, the best solution to combat ocean acidification is to reduce carbon dioxide emissions. Click here for ways to personally reduce your carbon footprint. Creating marine protected areas and halting harmful fishing practices will also boost the resiliency of the ocean and its diverse marine life. There are numerous marine organizations that are addressing ocean acidification, including the Ocean Foundation, which provided helpful background in preparing this report.