Carbon Cycle and The Influence Of Marine Animals

Animals inhale oxygen and exhale carbon dioxide at all times as opposed to plants.

Hence, there is a balanced mix of both oxygen and carbon dioxide in the atmosphere. But with the rise in the number of automobiles and factories, the amount of carbon emissions is way more than what the atmosphere could bear. A balancing act that has lasted hundreds of millions of years is now out of balance resulting in a net gain of atmospheric carbon dioxide.

The increasing carbon dioxide has many ramifications including climate change, sea-level rise, and ocean acidification. This causes problems to the entire life system on the planet. There is an urgent need to optimize the carbon cycle and balance our carbon footprint.

Scientists note that the ocean temperatures are rising at the rate of five Hiroshima bombs a second. Studies prove that 80 to 90 percent of the heat from global warming is actually going into the oceans. The oceans are considered to be Earth’s heat bucket, where the most heat winds are trapped as oceans can absorb a thousand times the heat as the atmosphere. 

To counter the increase in carbon emissions in the atmosphere, we need to reduce the use of fossil fuels and increase the capacity of the planet to absorb more carbon by planting trees.

Most of us are aware that trees and other terrestrial plants are a major part of the carbon cycle, but we may not be aware of the fact that more CO2 is absorbed by life in the ocean than on the land. The CO2 absorbed by ocean organisms is called ‘Blue Carbon’. The fish, the mammals, and other marine vertebrates help in keeping coastal habitats healthy, when these species are gone the ocean loses its carbon absorption capacity.

Biomixing Carbon

Influxes of nutrients from whale waste products such as urea can help stimulate phytoplankton growth. As denser particles sink, many nutrients settle down at the bottom of the ocean. Whales and other fish physically mix the water column by swimming throughout the water column providing nutrients to the plants at the surface of the ocean, an effect researchers term Biomixing Carbon. Plants such as phytoplankton play an essential role in absorbing carbon hence optimizing the carbon cycle. 

Whales in Climate Fight

Great whales are the carbon-capture titans of the animal world, absorbing an average of 33 tons of CO2 each throughout their lives. Whales travel thousands of miles, feeding and producing waste matter along the way. The fecal matter of whales stimulates phytoplankton production. Not only that, as whales are large and long-lived, they store a huge amount of carbon in their bodies and when they die, they sink and a lot of carbon in them gets stored for billions of years. So, this carbon gets retired from the carbon cycle.

Some fish such as tuna produce calcium carbonate as a waste product which can potentially offset the effects of ocean acidification. 

Source: Grida.no

Marine vertebrates play a key role in keeping the planet healthy. A lot of international organizations and various governments of countries and independent bodies are taking measures to reduce carbon by preventing illegal fishing, ocean recreation, and establishing marine protected areas. The International Whaling Commission passed two resolutions in 2018 that recognized whales’ value for carbon storage. As science advances in this field, protecting marine vertebrate carbon stocks ultimately might become part of national pledges to fulfill the Paris Agreement.

“Recognizing the role marine life may play in mitigating climate change may help small island developing states, especially those who are large ocean nations, include ocean actions in their Nationally Determined Contributions under the Paris Agreement,” says Ronald Jumeau, Permanent Representative to the United Nations and Ambassador for Climate Change for the Republic of Seychelles.

To help save the ocean’s plants and animals as well as the people who rely on them for their livelihood and food, we need to go zero on new CO2 emissions and need to find ways to remove trillion tons of atmospheric CO2. A process called Ocean Alkalinity Enhancement which accelerates the geologic cycle consuming both carbon dioxide and ocean acidity is in practice today. However, if we reduce our carbon emissions drastically, the oceans and terrestrial plants can help maintain a balance of carbon in the atmosphere.