A whale fall occurs when the carcass of a whale has fallen onto the ocean floor at a depth greater than 1,000 m (3,300 ft), in the bathyal or abyssal zones. On the sea floor, these carcasses can create complex localized ecosystems that supply sustenance to deep-sea organisms for decades. This is unlike in shallower waters, where a whale carcass will be consumed by scavengers over a relatively short period of time. Whale falls were first observed in the late 1970s with the development of deep-sea robotic exploration. Since then, several natural and experimental whale falls have been monitored through the use of observations from submersibles and remotely operated underwater vehicles (ROVs) in order to understand patterns of ecological succession on the deep seafloor.
A chemoautotrophic whale-fall community in the Santa Cruz basin off southern California at a depth of 1,674 m (5,492 ft), including bacteria mats, vesicomyid clams in the sediments, galatheid crabs, polynoids, and a variety of other invertebrates.
The skeleton of a gray whale lies on the Santa Cruz Basin seafloor as a hagfish swims into view of the US Navy's deep-sea submersible Alvin.
Distribution of currently known whale falls in the world. (May 2022)
A whale bone being recovered from the Santa Catalina Basin floor five years after experimental emplacement. The bone surface contains patches of white bacterial mats and a squat lobster. Hydroids have sprouted on the loop of yellow line attached to the bone.
The bathypelagic zone or bathyal zone is the part of the open ocean that extends from a depth of 1,000 to 4,000 m below the ocean surface. It lies between the mesopelagic above and the abyssopelagic below. The bathypelagic is also known as the midnight zone because of the lack of sunlight; this feature does not allow for photosynthesis-driven primary production, preventing growth of phytoplankton or aquatic plants. Although larger by volume than the photic zone, human knowledge of the bathypelagic zone remains limited by ability to explore the deep ocean.
Champagne vent, a hydrothermal vent on the Northwest Eifuku seamount.
Particulate organic matter (marine snow) traveling through the water column.
A type of archaea, Crenarchaeaota are linked to dissolved inorganic carbon fixation.
ROV Jason