Why We Need Whales
The implications of human activity on these whales may hold seemingly little significance, but as the largest beings to live on this planet, the importance of whales in the overall biosphere is only just being understood. According to a study by a group of scientists from the Australian Antarctic Division and the Antarctic Climate and Ecosystems Cooperative Research Centre (ACE CRC), whale faeces play a vital role in the health of the ocean.
“When whales consume the iron-rich krill, they excrete most of the iron back into the water, therefore fertilising the ocean and starting the whole food cycle again,” Australian Antarctic Division scientist, Dr Steve Nicol, explains. He says that before commercial whaling, baleen whale faeces may have been responsible for about 12 percent of the iron content in the surface layer of the Southern Ocean.
These iron-rich krill feed on phytoplankton, which consume whales’ faeces and store the iron. Though micro-sized, these organisms have a very big role in the ocean – they have the ability to photosynthesise. This means that they are responsible for absorbing carbon dioxide and releasing oxygen. As such, research suggests that increasing baleen whale and krill populations will improve the ocean’s ability to absorb carbon dioxide.
Before commercial whaling, baleen whale faeces may have been responsible for about 12 percent of the iron content in the surface layer of the Southern Ocean
This cyclic process suggests a significant role on a global scale that whales have played and, by necessity, need to play, to counter the present global warming situation. With the blue whale being the largest and once prolific member of this life support system, their dwindling numbers pose a great danger to the ocean’s health.
“When we started adding it all up, it was astonishing,” Robert Rocha, Director of Science at the New Bedford Whaling Museum in Massachusetts exclaims in response to the findings of his study, “Emptying the Oceans: A Summary of Industrial Whaling Catches in the 20th Century”.
The researchers estimate that, between 1900 and 1999, 2.9 million whales were killed by the whaling industry: 276,442 in the North Atlantic, 563,696 in the North Pacific and 2,053,956 in the Southern Hemisphere.
An adult blue whale is dependent on 6.3 million kilojoules each day, and this primal urge to eat is a strong driving force that propels it forward. Along the northeast coast of Sri Lanka, the Eastern Monsoon weather pattern creates upwellings that proliferate masses of krill, and it is here that blue whales come to feed and attract divers and snorkellers who hope to catch glimpses of these monoliths of evolution. If we don’t prioritise the recovery of these oceanic mammals, not only will we lose a species that invites such wonder, but we may also be giving up on a key warrior against climate change.