As more is learned about the ways in which whales sequester carbon dioxide in great quantities; the more scientists and marine biologists are convinced that their protection is vital. The benefits of a healthy whale population is clear as they are helping to fight climate change and their mass slaughter during the 19th and 20th centuries could have exasperated global warming. Research continues, but many stark facts have already emerged…
Climate change is affecting sea temperatures, the dilution of the sea water and acidification. The levels of the oceans is rising and many of the marine habitats are changing. Whales are helping to combat these climate changes, but we need more whales. https://www.good.is/whales-climate-change-study
Whales provide up to 50% of the earth’s oxygen. They deal with a huge quantity of carbon dioxide in a variety of ways. The first way is that their store huge quantities of the gas within their bodies. The CO² remains inside them throughout their lives and when the whale dies, its body sinks to the ocean floor – taking its large store of CO² with it. The gas remains within the carcass on the sea floor for thousands of years. As National Geographic website explains- ‘A study published in 2010 estimated that eight types of baleen whales, including blue, humpback, and minke whales, collectively shuttle nearly 30,000 tons of carbon into the deep sea each year as their carcasses sink. If great whale populations rebounded to their pre-commercial whaling size, the authors estimate this carbon sink would increase by 160,000 tons a year’.
Whales eat huge quantities of carbon when they are feeding as their diet is mainly krill, plankton and small fish. Whales also aid the absorption of carbon by their regular diving pattern. The whales dive from the ocean’s surface down to the greatest depths. This movement tends to push nutrients from the deep up to the surface where they feed to phytoplankton and other marine flora which both absorb large quantities of carbon dioxide. These nutrients are also eaten by many small fish and other marine creatures.
Whales regularly surface to breathe, but also to excrete huge faecal plumes near the surface of the water. These faecal plumes are rich in iron, nitrogen and phosphorous. The plumes are light and foamy so they float and these help to fertilise the plankton and other marine plants – encouraging their growth. Scientists have found that the more whales there are in an area, the greater the presence of plankton and other plant life. National Geographic website points to some interesting statistics on this – ‘Another study from 2010 found that the 12,000 sperm whales in the Southern Ocean draw 200,000 tons of carbon out of the atmosphere each year by stimulating phytoplankton growth and death through their iron-rich defecations’.
The Phytoplankton and other marine plants float on the surface of the ocean and use photosynthesis to feed and absorb large amounts of carbon dioxide from the atmosphere. The phytoplankton eventually sinks to the ocean floor with its trapped carbon dioxide. The phytoplankton remains on the seabed for thousands of years, taking large amounts of carbon out of the atmosphere. https://www.unenvironment.org/news-and-stories/story/ protecting-whales-protect-planet
There are many studies being made on whale populations throughout the world. ‘Scientists have made progress in terms of pinpointing exactly how much carbon whales keep out of the atmosphere; one study suggests that every year, sperm whales help sequester as much carbon as 694 acres of U.S. forests do. Another found that in Hawaii, the swimming motion of 80 whales can absorb the equivalent carbon of 208 acres of U.S. forests. But there’s still a huge degree of uncertainty here. (Scientific American)
One of the main problems is that although the high value of whales in the ecosystem of the oceans is now being understood, the urgency to stem global warming is not and the rise in the oceans’ temperature must be stopped. Whales are very mobile and as the ocean waters steadily get warmer in places, the whales may not be able to survive in these areas. It’s difficult to predict just how climate change will affect the different whale species yet, but it will have a negative impact because whales are part of a complicated ecosystem with the survival of many species closely interlinked with that of the whales.
Scientists recognise that whales are crucial in the absorption of carbon. As the numbers of whales are (in reality) being barely maintained, this could lead to increased greenhouse gases in the atmosphere and a continuing increase in global warming. If, the global conservation of whales really is given top priority, whales could play an even greater role in the reduction of CO² and a downturn in global warming which is the greatest threat that the world faces. ‘Food for thought’ from the National Geographic website- ‘There are about 1.3 million great whales in Earth’s oceans today. If we could restore them to their pre-commercial whaling numbers—estimated at between 4 and 5 million— the economists’ calculations show that great whales could capture about 1.7 billion tons of carbon dioxide each year – more than the annual carbon emissions of Brazil’.
However, it’s only a few percent of the 40 billion tonnes of carbon dioxide humanity spews into the air each year. And even with aggressive global conservation efforts, it could be decades before great whales rebound to their pre-whaling numbers, assuming that’ is possible at all given how much we’ve degraded the oceans’….