Our planet’s ocean ecosystems are started affecting by the acidification of water. The rate of acidification of water is at a faster rate than ever in the last 55 years.It is feared that if greenhouse gases continue to go up, sea water acidity could increase by 120 per cent by 2060 – greater than anything experienced in the past 21 million years.The Copenhagen climate conference termed this issue as ‘underwater time-bomb’ that threatens fish stocks, marine life and coastal communities around the world.
Ocean acidification can be simply defined as an ongoing decrease in the pH of the Earth's oceans, caused as a result of their uptake of anthropogenic carbon dioxide from the atmosphere. Approximately 79 million tons of carbon dioxide (CO2) released into the atmosphere every day, not only as a result of fossil fuel burning but also of deforestation and production of cement . Since the beginning of the industrial revolution, about one third of the CO2 released in the atmosphere by anthropogenic (human-caused) activities has been absorbed by the world’s oceans, which play a key role in moderating climate change.
The Carbon Cycle
The Carbon Cycle is a complex series of processes through which all of the carbon atoms in existence rotate. Carbon exists in the Earth's atmosphere primarily as the gas carbon dioxide (CO2). Although it is a small percentage of the atmosphere (approximately 0.04% on a molar basis, and increasing), it plays a vital role in supporting life.
Carbon is released into the atmosphere in a number of ways like expiration, decay of animals and plants ,production of cement, volcanic eruptions ,combustion of organic materials etc. Burning fossil fuels such as coal, petroleum products, and natural gas releases carbon that has been stored in the geosphere for millions of years.
Trees convert carbon dioxide into carbohydrates during photosynthesis, releasing oxygen in the process. This process is most prolific in relatively new forests where tree growth is still rapid. Forests store 86% of the planet's above-ground carbon and 73% of the planet's soil carbon. Oceans absorb a great amount of CO2 and carbonic acid is formed. In upper ocean areas of high biological productivity, organisms convert reduced carbon to tissues, or carbonates to hard body parts such as shells and tests. These are, respectively, oxidized (soft-tissue pump) and redissolved (carbonate pump) at lower average levels of the ocean than those at which they formed, resulting in a downward flow of carbon.
Impact Of Ocean Acidification On The Ocean Ecosystems.
Oceans absorb approximately one quarter of the carbon dioxide emitted to the atmosphere from the burning of fossil fuels, deforestation, and other human activities. As more and more carbon dioxide (CO2) has been emitted into the atmosphere, the oceans have absorbed greater amounts at increasingly rapid rates.
Marine calcifiers, such as corals and marine snails, play important roles in nearly all oceanic ecosystems. Ocean acidification makes it more difficult for marine calcifiers to build shells and skeletons and will likely threaten ecosystem dynamics in areas where marine calcifiers play dominant roles in the food web. The effects of elevated greenhouse gas concentrations could cause substantial coral reef loss on tropical and sub-tropical reefs by 2050.It is estimated that by 2100 some 70% of cold water corals, a key refuge and feeding ground for commercial fish species, will be exposed to corrosive waters.
What Can We Do About It?
Combating acidification requires reducing CO2 emissions and improving the health of the oceans. Creating marine protected areas (essentially national parks for the sea) and stopping destructive fishing practices would increase the resiliency of marine ecosystems and help them withstand acidification.
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