“Threatening Ocean Life from the Inside Out” by Sarah J. Hardt and Carl Safina discusses the detrimental effect ocean acidification has on sea-life and how the rise in acidity is hurting the oceanic food chain and habitats. Ocean acidification can be defined as too much carbon dioxide in the atmosphere reacting with ocean water and is forming carbonic acid.
This uptake is caused by the CO2 output by humans. The effects of ocean acidification affect the abilities of calcium carbonate dependent sea-life. More simply, ocean acidification is harming corals and animals are having a hard time building skeletons and shells. It is not just the structure of the organism that is being harmed but also the bodily functions like growth and reproduction.
You can see that this is harmful to populations of sea-life, without reproduction some species may fail to exist. The ocean is soaking up our harmful emissions, “the atmospheric CO2 concentration is almost 390 parts per million, but it would be even higher if the oceans didn’t soak up 30 million tons of gas every day. The world’s seas have absorbed roughly one-third of all CO2 released by humans”(68) and are paying the price. An example of how terribly wrong this can be was approximately 250 million years ago when volcanos erupted and doubled the atmospheric CO2. Many species started to die off and now are extinct. The article refers to the ocean as a layered cake, each layer having its own temperature and salinity.
Organisms pass through these different layers, acidities, day to day. This change between layer is harmful to the fish because they have to keep up their internal pH balance. The upkeep of the pH uses energy that they could be using on other processes like reproduction, growth, synthesizing proteins and maintaining the immune system. Even small increases in the ocean’s acidity can harm water-water-creating organisms by making their tissue more acidic.
The issue becomes more acidic because more hydrogen ion being sent into the animals’ bodies. An example of an organism’s fertilization success plummeting. is one of the sea urchins. Although the sea urchin produced many sperms at once when experimenter lowered the seawaters pH fertilization success. Phytoplankton, the base of the food chain, is another concern. The acidification makes it harder for these organisms to absorb iron which helps them grow. When they have a hard time growing, it hinders the food chain and reduces the oxygen we breathe.
The reduced immune function, reproductive success, and growth is a problem but acidity reduces strength. These problems cause population declines that affect species that rely on them for food or upkeep of habitat. A squid, for instance, has no oxygen storage and the less oxygen they have limited their ability to hunt, find mates and stay away from predators. Not all organisms struggle like the spotted wolffish. They have seen to have a tolerance to the acidity due to their extra storage of oxygen in their tissues.
The extra storage of oxygen in their tissue helps them because hydrogen ions that are supposed to hinder their capacity to soak up oxygen from the water, don’t. There were many experiments shared in the article and “the message of lab studies as well as the geologic record is that ocean acidification forces animals to toggle harder, which today they are already doing because of other human-induced stressors such as warming waters, pollution, and overfishing”(72).
Some species could adapt each time they reproduce if they have a short reproduction cycle but adaption seems very unlikely. The future of natural selection seems scary, “unabated acidification could completely restructure marine ecosystems, with cascading effects across the food chain. Some species might thrive on a new combination of plankton while others suffer but there is no telling if the species that we depend on most will be the winners.
The changes could also hurt tourism and erase potential pharmaceutical and biomedical resources”(72). There is another effect ocean acidification has on the planet, not just the ocean. Ocean acidification will throw off the planet’s carbon cycle. Oceans absorb a large amount of CO2 but as the rate slows down, there will result in faster global weather challenges. The first can to start dissolving shells and skeletal structures in the Southern Ocean which is by Antartica.
There is no reverse to ocean acidification but prevention. At the end of the article, the authors suggest a National Ocean Policy that could implement prevention to this impending disaster. They also call for more government intervention and funding for research. For the oceans to have a healthy future there needs to be a new energy economy where fossil fuels are reduced.
- Frontiers in Physiology: Ocean Acidification Effects on Atlantic Cod Larvae Survival and Recruitment to the Fished Population
- Science Magazine: Rising Acidity in the Ocean: The Other CO2 Problem
- NOAA’s National Ocean Service: What is Ocean Acidification?
- Proceedings of the National Academy of Sciences: Ocean acidification causes bleaching and productivity loss in coral reef builders
- NASA: The Ocean Carbon Cycle