The ocean makes up seventy percent of our planet’s surface, ninety-nine percent of its living space, and is a habitat to an estimated fifty to eighty percent of life on Earth. The world is suffering from the effects of rising carbon dioxide emissions, and our oceans are not an exception. Carbon dioxide emissions from the use of fossil fuels are rising exponentially, and the Alaska Ocean Acidification Network reports that approximately half of these emissions are absorbed into the ocean. This means that out of the 4.5 billion tons of emissions in 2017, the ocean took up 2.6 billion tons. As excessive carbon dioxide dissolves into the oceans, the pH levels begin to drop. This phenomenon is referred to ocean acidification, and is detrimental to shelled sea life, especially in Alaskan waters.
What is a pH level?
As described in the United States Geological Survey (USGS), pH is a measure of how acidic or basic water is. Acidity is measured by the relative amount of free hydrogen and hydroxyl in the substance. This further determines the substance’s solubility and biological availability of for example, nutrients for aquatic life. The range of the pH scale is zero to fourteen, with seven being neutral. The lower the pH, the more acidic the substance is, and the higher the pH, the more basic. For reference, safe drinking water would be considered neutral, with a pH between 6.5 and 8.5, while sodas are within the 2.1 to 4.0 range. The graphic below from the USGS illustrates other common items and their pH levels:
How does the ocean acidification affect shelled organisms?
Scientists reported to the Alaska Ocean Acidification Network that the ocean is about 30% more acidic today than it was 300 years ago. The rising acidity of our oceans negatively affects the ability of shelled organisms to build and maintain their shells. This would include organisms such as crabs, clams, mussels, and even urchins and starfish whose growth has been stunted. According to the National Oceanic and Atmospheric Association (NOAA), shelled creatures use calcium dissolved in the water to form their shells. The more acidic the water is, the harder is it for those organisms to take up the mineral. As a result, their growth delays, their shells are built more softly, and they become more susceptible to being eaten by predators.
Chris Long of the NOAA Alaska Fisheries Science Center states, “A lot has to do with the stage in life that a crab is exposed to more acidic conditions (lower pH levels) than normal.” The worst ramifications are in the embryo stages of shelled organisms, where they are unable to tolerate acidic conditions very well. Less are making it to adulthood, which has effects on the ecosystem, the prosperity of the species, and its population. For fishermen, this means less seafood to eat and sell.
Why Alaska?
The focus of ocean acidification discussions has been on Alaska because it has been experiencing the phenomenon the fastest. The Alaska Ocean Acidification Network explains that because of their cold waters and the global circulation patterns, Alaskan waters hold more carbon dioxide than other bodies of water. Thus, Alaska is ahead of the rest of the world in terms of ocean acidification and its effects, therefore it can be used to better prepare for Alaska and the rest of the world’s future. In addition, Alaskan people and employees are reliant on the well-being of their sea life because they rely on the ocean for both their own food and the seafood industry. Almost half of the seafood in the U.S. comes from Alaska, so these effects will additionally harm the food source and economy of Alaska and the rest of the states.
Studies and Experiments
The NOAA cites a study done on blue king crabs, in which scientists observed slower growth rates and higher mortality rates in juveniles exposed to more acidic conditions. In the experiment on the right, courtesy of Eurekalert, three shelled species (hard clam, bay scallop, and
Eastern oyster) were raised in two different environments: one with high (right column) and one with low (left column) carbon dioxide concentration in the water. The species raised in the highly concentrated water took longer to develop and their shells were much weaker than their counterparts. This exemplifies what is beginning to happen in the ocean’s waters and the affect ocean acidification has on shelled species. And, that the cause for stunted growth are acidic conditions.
Can these organisms just adapt?
The rules of natural selection and organisms adapting to their environment have not gone away. This part of nature still plays a role in which survive, and which do not. Though, the problem is not a lack of ability in adapting, but the speed that these organisms are able to adapt. The changes brought by ocean acidification does not occur naturally and are happening too quickly for the organisms to adjust.
So far, there is no concrete answer to this question. However, scientists can confidently claim that ocean acidification is not in the best interest of sea life and humankind. Ocean acidification has detrimental effects on both groups, as do the other side effects of our destructive nature towards the Earth. As years pass, the effects become increasingly irreversible and the only solution in sight is to greatly diminish and ideally halt our excessive emissions of carbon dioxide into the atmosphere.