Zhemchug Canyon
Zhemchug Canyon is an underwater canyon located in the Bering Sea between the Siberian and Alaskan coastlines. It is the deepest submarine canyon in the world with a vertical relief of 8,530 feet and a length of 99 miles. The canyon is renowned for its extraordinary size and unique marine environment. It forms a significant portion of the Bering Sea's ecosystem, contributing to its biological productivity and natural habitat for a diverse range of marine species.
Geography
The Zhemchug Canyon is located in the middle of the Bering Sea, between Siberia and Alaska. It has a vertical relief of dropping from the shallow shelf of the Bering Sea to the depths of the Aleutian Basin and a length of 99 miles. The Zhemchug Canyon is deeper than the Grand Canyon which is deep. It has two main branches, each larger than typical continental margin canyons such as the Monterey Canyon. What makes the Zhemchug Canyon the world's largest is not only its great depth, but its immense cross-sectional and drainage area and volume.The canyon holds a distinct hydrographic condition due the canyon's complex topography. The Canyon's structure impacts the local water circulation, and creates an upwelling of nutrient-rich water from the deeper regions of the oceans. This upwelling is what supports the active marine wildlife observed in the region. Additionally, the canyon interacts with other major ocean currents, such as the Bering Slope Current which flows along continental slope that brings nutrient rich water from the Arctic.
In 2016, Michelle Ridgeway explored the canyon piloting an eight-foot submarine in an expedition sponsored by Greenpeace. She reached a shelf at a depth of, that is, a third of a mile below the surface.
Ecology
The ecology of the Zhemchug Canyon holds rich biodiversity and complex food webs, supported by the canyon's unusual physical structure and oceanographic conditions. The canyon's depth, shape, and nutrient flow support a variety of habitats and marine life across varied ecological niches.Phytoplankton and nutrient cycling
The unique contours of submarine canyons like Zhemchug create particularly favourable upwelling conditions, increasing the circulation of nutrient-rich waters from the deep seafloor; as a result, Phytoplankton density in the Canyon is significantly higher than surrounding waters. The dense Phytoplankton population serve as the Canyon's primary producers, supporting the rest of the Canyon's food web.Marine fauna
The phytoplankton population supports a large population of zooplankton, which in turn are a key food source for a variety of fish species. The Zhemchug hosts both pelagic and demersal fish such as the Aleutian Flounder, Bering Skate, and Pacific Cod. These fish find food from the canyon and use the canyon's topography for shelter and spawning.Species adapted to the colder and high-pressure environment live in the deeper regions of the canyon. Deep-sea sharks and cephalopods, such as the Giant Pacific Octopus, are found often along canyon walls.