One whale’s unfortunate death can be an entire ecosystem’s blessing, recent research shows.
A large international team of marine researchers monitored the seafloor surrounding the corpse of a whale that had sunk 4,920 feet (1,300 meters) deep in the waters near Vancouver Island, Canada. Over a 15-year-long span, and probably longer, the whale sustained a rich community of deep-sea life, they found. The researchers expect that the whale will continue to be an ocean buffet for years to come.
Whale falls
Scientists first began to document the appearance of whale corpses along the deep ocean floor in the 1970s—a phenomenon known as a whale fall.
The sheer mass of a whale that sinks to the bottom of the ocean can provide a sudden burst of bountiful resources to the area. And the usually cold temperatures and high pressure found in the ocean depths allow the whale to stay intact far longer than it would had it died in shallower waters.
The dead whale still goes through varying stages of decomposition, which benefits different types of life. At first, opportunistic scavengers will feast upon the soft tissues of the whale, usually picking it clear within months. After that, creatures will live off the bones and remaining organic matter of the whale. Following that, there’s the sulfophilic stage, where anaerobic bacteria survive by breaking down the lipids inside a whale’s bone. These bacteria create sulfur, rather than oxygen, from this process, thus creating a unique environment for other deep-sea organisms to thrive in. Lastly, the remaining mineral skeleton left of the whale can help create reefs.
According to the researchers, there’s still a lot of mystery about how long the sulfophilic stage can last, particularly in the northeast Pacific Ocean. So they sought to keep tabs on a particular whale fall that was first discovered in 2009 at the Clayoquot Slope off Vancouver Island. The deceased was likely either a blue or a fin whale.
All told, four trips were taken to the area between 2012 and 2024, though only two were explicitly intended to monitor the site (2023 and 2024).
Between those years, they found, the skeleton had barely eroded. The whale’s vertebrae, for instance, only shrunk in length by only 1.4%. And life has continued to bloom around it. In 2009, 29 distinct broad groups of deep-sea critters, or taxa, were observed in or around the whale; by 2023, that count had increased to 31 taxa. These included tube worms, clams, and gastropods. By 2023, they also observed bone-eating Osedax worms, a clear sign of transition to the sulfophilic stage.
Based on their observations, the sulfophilic stage of this whale has lasted at least 21 years. And the party isn’t likely to end anytime soon. They expect that the whale’s cranium and vertebrae will continue to feed these bacteria for at least another decade.
Threatened by climate
The team’s findings, published in the journal Frontiers in Marine Science, will help researchers better understand how whale falls shape the environment around them. Unfortunately, warming waters will probably endanger these environments in the northeast Pacific Ocean, the authors warn.
Climate change is directly affecting the recovery of whales in the area, such as the gray whale, mostly by altering the populations of prey they feed on, the researchers note. It’s also fueling the expansion of low-oxygen environments on the seafloor, known as oxygen minimum zones, which are further harming the stability of many marine areas, likely including whale falls.
“We posit that whale-fall ecosystem function and associated biodiversity may be threatened by widespread expansion of seafloor low oxygen environments on the Cascadia Margin,” they wrote.
