14 DAY TRIAL // There are many examples in nature of organisms or animals that are able to construct, steal, or generate a mobile home for themselves that can protect them against predators, or camouflage them. While many species employ various means of achieving this, none is arguably more extreme than those employed by foraminifera. These are single-celled creatures that live more than 10 kilometers under the surface of the ocean, and apparently use materials sinking from the surface to design their homes.
Data for the new investigation was collected from the Challenger Deep, a region of the Mariana Trench. The Deep is the lowest known elevation point on our planet's crust, sinking more than 11,033 meters (36,200 feet) below sea level. Its home is the hadal zone, which lies beyond the abyssal zone. “The hadal zone extends from around six kilometers to the deepest seafloor,” explains National Oceanography Center, Southampton (NOCS) expert professor Andrew Gooday.
“Although the deepest parts of the deepest trenches are pretty inhospitable environments, at least for some types of organisms, certain kinds of foraminifera are common in the bottom sediments,” the scientist adds. He was also a member of the UK-Japanese research team that investigated samples collected from the Deep, and found traces of these organisms. The samples were gathered during an expedition conducted by researchers in the United States, Korea and Japan, which was aimed at studying life in the western depression of the Challenger Deep.
The area “is an extreme environment for agglutinated foraminifera, which construct their tests from a wide range of particles cemented together by calcareous or organic matter. At these great depths, particles made from biologically formed calcite and silica, as well as minerals such as quartz, should dissolve, leaving only clay grains available for test building,” he explains. “Our observations demonstrate that coccoliths, and probably also planktonic foraminiferan tests, reach the Challenger Deep intact. These particles were probably transported to these extreme depths in rapidly sinking marine snow, the aggregated remains of phytoplankton that lived in the sunlit surface ocean, or in fecal pellets from zooplankton,” Gooday concludes.