Whales, whether alive or deceased, are integral components of complex marine and terrestrial food webs, providing significant nutritional resources for diverse predators and scavengers. Their presence influences ecosystems from the ocean’s surface to its deepest abyssal plains, and even coastal environments.
Hunters of Live Whales
Orcas (Orcinus orca) are the primary hunters of live whales. These apex predators are intelligent and use cooperative hunting strategies to target whales, often much larger than themselves. Orca pods specialize in hunting marine mammals. Their diet can include various whale species such as minke whales, gray whales, humpback whales, and even the planet’s largest animal, the blue whale.
Orcas employ diverse techniques depending on the size and species of their prey. When hunting larger whales, they often focus on calves or sick individuals, though healthy adults are also targeted. The hunting process typically involves coordinated attacks where orcas ram, bite, and pull on the whale’s pectoral fins to exhaust it. They may also attempt to prevent the whale from surfacing to breathe, effectively drowning it. These learned behaviors are passed down through generations, showcasing their complex social structures.
Marine Carcass Eaters
When whales die, their carcasses, known as “whale falls,” become a concentrated food source that supports a unique succession of marine life, especially in the deep ocean. This process begins with mobile scavengers that consume the soft tissues. Large sharks, such as great white sharks and tiger sharks, are prominent among these initial feeders, drawn by the rich blubber and flesh.
As decomposition progresses, a diverse ecosystem develops around the sinking carcass. In the deep sea, where food is often scarce, a whale fall can sustain communities for decades. Organisms like hagfish, sleeper sharks, and various bony fish species are early arrivals, consuming the soft tissues over several months. Following this, specialized invertebrates like polychaete worms, crustaceans such as tanner and galatheid crabs, and mollusks feed on remaining blubber and organic fragments in the surrounding sediment.
The bones provide a long-term food source, as bacteria break down lipids within them, supporting specialized worms (Osedax spp.) and other chemosynthetic organisms. This nutrient recycling at whale falls significantly enriches deep-sea environments, creating biodiversity hotspots.
Land and Ice Scavengers
Whale carcasses that wash ashore on coastlines or become trapped in ice provide substantial food for terrestrial and ice-dwelling scavengers. Polar bears (Ursus maritimus) in Arctic regions opportunistically feed on stranded whale carcasses, such as bowhead and gray whales. These large food sources are particularly valuable when sea ice is low, making their primary prey, seals, harder to hunt. A single large whale carcass can provide fat and protein for numerous polar bears, with dozens or even over a hundred bears observed feeding on one whale.
Along coastal areas, brown bears may feed on these remains. Various bird species, including bald eagles, gulls, and corvids, are also common scavengers, consuming soft tissues. These events show how whale deaths sustain diverse animal populations across different environments.