Saving whales can slow global warming
Over a lifespan of around 60 years, every great whale absorbs about 33,000 kg of carbon dioxide over its life, whereas one tree absorbs up to 22 kg per year.
The term “Great Whales” covers the Odontoceti family Physeteridae (sperm whales), the Mysticeti families Balaenidae (right and bowhead whales), Eschrichtiidae (grey whales), and some of the Balaenopteridae (Minke, Bryde’s, Sei, Blue and Fin; not Eden’s and Omura’s whales).
Furthermore, wherever the whales go, phytoplankton grows – these tiny sea creatures absorb about 40% of all CO2 – that’s as much as 1.7 trillion trees or four Amazon rainforests.
Even the dead bodies of whales help: when a whale dies, its carcass sinks to the seafloor, bringing tons of carbon with them, a process called Deadfall Carbon. On the deep seafloor, it can be eventually buried in sediments and potentially locked away from the earth’s atmosphere for millions of years.
A 2010 study estimated that a historic pre-whaling population of 120,000 sperm whales could have trapped 2.2 million tons of carbon yearly through their poo.
Another 2010 study, titled “The Impact of Whaling on the Ocean Carbon Cycle: Why Bigger Was Better”, calculated that the global pre-whaling population of approximately 2.5 million great whales would have exported nearly 210,000 tons of carbon per year to the deep sea through Deadfall Carbon. That’s equivalent to taking roughly 150,000 cars off the road each year.
More whales mean more phytoplankton
Whales promote the growth of phytoplankton in two ways.
- The movement of whales pushes nutrients from the bottom of the ocean to the surface, which feeds phytoplankton and other marine life.
- The second way they help with carbon absorption is through their poop. Whales’ waste products contain exactly the substances – notably iron and nitrogen – phytoplankton need to grow.
A 1% increase in phytoplankton productivity is equivalent to 2 billion mature trees.
Using nature’s own technology to fight global warming
Sadly, humans almost drove whales to the brink of extinction. Whaling by humans has existed since the Stone Age. Throughout the 17th, 18th, and 19th centuries, commercial whaling was historically important as an industry and hundreds of thousands of great whales have been killed.
Though industrialized whaling was banned in most places in 1986, their numbers are at a quarter of what they once were. Meanwhile, carbon dioxide is at its highest level in 3 million years. So, finding ways to absorb it is critical.
Saving whales and restoring their numbers could absorb 1.3 billion tonnes of CO2 every year.
A recognition of the contribution whales make could be a valuable alternative to costly and untested proposed technological solutions, such as capturing carbon directly from the air and burying it deep underground.
Whales can also be threatened by humans more indirectly. They are unintentionally caught in fishing nets by commercial fisheries as bycatch and accidentally swallow fishing hooks.
They are also affected by marine pollution. High levels of organic chemicals accumulate in these animals since they are high in the food chain. They have large reserves of blubber, more so for toothed whales as they are higher up the food chain than baleen whales. Lactating mothers can pass the toxins on to their young. These pollutants can cause gastrointestinal cancers and greater vulnerability to infectious diseases.
Whales can also be poisoned by swallowing litter, such as plastic bags.
Advanced military sonar also harms whales. Sonar interferes with the basic biological functions of whales-such as feeding and mating-by impacting their ability to echolocate. Whales swim in response to sonar and sometimes experience decompression sickness due to rapid changes in depth. Mass strandings have been triggered by sonar activity, resulting in injury or death.
- “Whales are vital to curb climate change – this is the reason why” on the World Economic Forum website
- Whale on Wikipedia
- “New study finds whales might be our best defense against climate change” on the Good website
- Sea creatures store carbon in the ocean – could protecting them help slow climate change? on The Conversation