In a decade filled with environmental action, it was one of the most visible – and successful conservation movements of all time. In April 1975, a little-known environmental group called Greenpeace launched the world's first anti-whaling campaign from the docks of Vancouver. The mission would become the spark that ignited a global Save the Whales movement, which would transform world opinion, leading to the International Whaling Commission’s (IWC)1982 decision to implement a moratorium on commercial whaling. Since 1986 commercial whaling has been effectively banned.
This unprecedented conservation action has seen some whale numbers rebound. For example, while there were only 450 Western South Atlantic humpback whales in the mid-1950s (from around 27,000 in the 1830s), they have recovered to 93 per cent of their pre-exploitation population. Indeed, most populations of humpback whales are estimated to have almost fully recovered. Yet while most will celebrate this rebounding of whale numbers, the role that whales play in carbon sequestration is less well known and highlights the importance of protecting whales from both a biodiversity and climate action perspective.
Whales store huge amounts of carbon during their long lives. For example, blue whales store up to 63 tons of CO2 and minkes 2.2 tons CO2 per individual, in the form of carbon (1 ton of carbon is equivalent to 3.67 tons of CO2). When whales die, they – in most cases – sink to the bottom of the ocean, taking the carbon out of the atmosphere for centuries or even millennia.
Whale and Dolphin Conservation (WDC), is a global charity dedicated to protecting whales and dolphins around the world. “We work around the world, through campaigning, lobbying and advising governments, carrying out conservation projects, and running education and engagement activities, says WDC’s Green Whale Manager, Ed Goodall. “Our vision is for a world where every whale and dolphin is safe and free and we use and support the latest science to strengthen the case for protecting whales and dolphins, as vital climate allies and ecosystem engineers and as intelligent beings in their own right.”
While it might seem strange to think of whales and dolphins as “climate allies,” according to Goodall, they “play an outsize role in the ocean’s ability to fix, store and sequester carbon. They are a major part of the complex web of marine life which makes the ocean the planet’s largest carbon sink, moving around vital nutrients which stimulate the growth of phytoplankton.”
And when whales die, the carbon they store is locked away with them. “The carbon in the [whales] carcass gets broken down and consumed by all sort of species, and is then stored and cycled amongst the benthic community or locked into sediments where it can be locked away/sequestered for thousands, perhaps even millions of years,” Goodall says. “There are many places for a carbon atom to go, but generally, they stay down there in the deep sea once they are there.”
And wherever whales – the largest living animal on earth – are found, so are populations of some of the smallest: phytoplankton. These microscopic creatures have not only contributed at least 50 percent of all oxygen to our atmosphere, they have done so by capturing about 37 billion metric tons of CO2, an estimated 40 per cent of all CO2 produced.
“One study in the Greater Farallones National Marine Sanctuary, showed that these fallen whale carcasses accounted for roughly 60 per cent of the sanctuary’s annual carbon sequestration – more than the Sanctuary’s salt marsh, seagrass, and kelp combined,” Goodall says. “Whale carcasses that are washed up on shore also provide a huge boost to scavengers such as birds, crabs, and even polar bears, and increase the nutrients in the soil where they lie.”
The short-term threats facing whales and dolphins come from multiple sources, Goodall says. “The greatest cause of harm and death comes from entanglement in fishing gear or ‘bycatch’. Hundreds of thousands of whales and dolphins, as well as other protected species, die in fishing gear each year. Bycatch levels are not monitored on most fishing fleets, so we do not know the true scale of the impact, and mostly bycatch occurs with no efforts to prevent it, leading to population level impacts in some fisheries – even in fish and other products that are apparently ‘sustainably’ sourced.”
Bycatch is such an issue, that despite the rebounding in most whale populations in the past few decades, some species are under serious threat. For example, there were only 366 North Atlantic Whales left at the end of 2021, the lowest number in 20 years.
One way to protect whales from bycatch is through the establishment of Marine Protected Areas (MPAs), where fishing is not allowed. WDC have been lobbying for the establishment of these areas since the early 2000s. “Governments are at last coming around to the 30 per cent protection by 2030, with more than 60 signing up to the idea so far, but it will take a lot of work to achieve these goals meaningfully,” Goodall says. One stumbling block is the lack of political will and the misconceptions around cost. “There is a perceived high cost of creating real protection that is effective in the ocean, when actually the benefits derived from protection and restoration of populations and ocean ecosystems would provide huge returns in ecosystem services,” Goodall adds.
Despite all the challenges, Goodall is optimistic for the future, pointing to the Save the Whale campaign as proof of what can be done when concerted global action is taken. “We have the capacity and ability to act and create global change, but action must be much deeper and holistic if we are to overcome the biggest challenge in the history of humanity,” he says.
Given the key role whales play in carbon sequestration, it is vital that we protect and nurture them, and add them to the list of Nature-based Solutions that can help steer us away from the climate crisis.
As Goodall says: “Life creates the conditions for life and is endlessly inspiring. To give up on nature would be the greatest travesty of all.”