led that at least two gray whales found dead near San Francisco Bay had been injured by ships, while an injured humpback whale was observed near Vancouver. Similar stories play out regularly around the globe.
And it’s not just big ships. Fishing vessels of all sizes pose threats, either directly or through lost fishing gear. This April a research drone captured footage of a baby gray whale entangled in fishing line, dragging a buoy behind it.
Warming oceans pose multiple threats to whales, some of which relate once again to the shipping industry. In recent years the industry has rushed to newly ice-free waters in the Arctic, bringing with them noise, pollution and other harmful changes.
Additional threats from climate change continue to emerge, and exactly what’s happening isn’t always clear. One recent study found that a population of bowhead whales failed to make its annual autumn migration away from solid ice in the Bering Sea, but the reason remains undiscovered. One theory is that warming waters could have resulted in an increase in their food supply. Another theory suggests changing temperatures could have allowed more killer whales to block the bowheads’ migration.
Similarly, climate change has resulted in decreased herring abundance in Quebec’s Gulf of St. Lawrence, and this loss of food has resulted in fewer humpback whale pregnancies coming to term.
Meanwhile, there’s a big reason to protect whales from climate change: their very existence helps protect us from climate change. Their feces help feed phytoplankton, which photosynthesize and absorb carbon dioxide before dying, sinking to the bottom of the ocean and sequestering that world-changing greenhouse gas. Whale bodies, similarly, also store an enormous amount of carbon that can be sequestered when they die.
When whales accidentally consume plastic waste that they find floating in the ocean, the results can be deadly — either immediately or over time.
All too often, investigations into the cause of whale deaths find plastic to blame. One of the most recent examples occurred in Bangladesh, where two dead whales washed up near a resort town in April. “Primarily we think the two have died from consuming plastic and polluted objects,” Jahirul Islam, executive director of Marine Life Alliance, told AFP.
And remember that new whale species that was just discovered? One of the reasons we know the species exists is because a carcass washed up near the Florida Everglades in 2019. Scientists found that it was killed by a tiny, 2.5-inch piece of jagged plastic that lodged in its stomach and caused internal bleeding and necrosis.
Smaller plastic particles may also have health implications for whales in even the most remote locations. A study published in 2020 found that seven beluga whales harvested by Inuvialuit hunters all had plastic fibers and fragments in their digestive systems. All the particles were what’s considered microplastic, smaller than 5 millimeters in size. These may not be immediately fatal, but nearly half of the particles contained chemicals that could cause potential health problems, much like they could in humans. The risks whales may face from microplastics remains a field of active scientific investigation, with hundreds of papers published in just the past year.
Larger plastic waste, such as lost or discarded fishing lines and nets, poses an even bigger threat. “Imagine walking around with weights tied to your ankles,” researcher Greg Merrill recently wrote in New Security Beat. “Whales struggle to get untangled from large nets and they end up dragging this weight along with them, expending extra energy they need to migrate and raise their young. An increasingly common tragedy is when whales become so overburdened by the weight of the plastic debris they cannot surface to breathe and drown.”
People generally love whales and support their conservation, but how much do they really know about whales and the threats the face?
Not much, it turns out.
A recent scientific survey found that the majority of people cared about legislation to protect whal