World Whale Day special: How is whale excreta saving the world

Whales! These majestic sea creatures are probably the most significant warriors in our battle against climate change. They are huge storage units of climate-heating carbon dioxide (CO2).

Whales accumulate carbon in their bodies during their long lives. When they die, they sink to the bottom of the ocean, locking that carbon away for hundreds of years — a literal carbon sink. Each great whale sequesters 33 tonnes of CO2 on average. That is equivalent to planting more than a thousand trees.

Interestingly, whale poop is also crucial to the functioning of the ocean and eventually survival of humans. Whales dive deep into the ocean to feed, and swim back up to the surface to breathe and excrete waste full of nutrients.

The excreta generated by the 100-150 tonne whale is food for the microscopic marine algae, phytoplankton. Phytoplankton also capture large amounts of CO2 and produce more than half of the world’s oxygen.

Phytoplankton are consumed by zooplankton and krill, which in turn fuel larger fish, sharks, and marine mammals. So ultimately, an abundance of whale poop means an abundance of phytoplankton and diverse marine life. The whole ocean thrives.

Sadly, 6 of the 13 ‘great whale’ species are endangered or vulnerable. The dangers include entanglement in fishing gear which kills 300,000 cetaceans a year, plastic pollution that whales confuse for food, collisions with ships, etc.

So, how do we save these ‘sentinel species of the sea’? WWF UK has created the first ever global map of whale migration patterns. It exposes growing dangers to the species and their superhighways.

Scientists combined satellite tracking data from 845 whales, collected over 30 years, and mapped it alongside the various growing dangers whales face. The map shows the bottleneck areas that need to be addressed urgently.

According to Simon Walmsley, chief marine adviser at WWF UK, the mapping exercise shows that whales are threatened along the whole length of their migration, along the whole ‘blue corridor’.

That means it is no use protecting whales in one place where they congregate. They need to be protected the full length of the migration route. In this regard, WWF UK is eyeing the upcoming UN high seas treaty. The treaty is expected to include a network of Marine Protected Areas, which are universally recognised.

Whales and climate change are inseparable but unfortunately the world has only around 350 North Atlantic Right whales left.