Between the ocean's surface and the seafloor lies the vast midwater zone—the largest habitat on Earth, encompassing roughly 90 percent of the planet's living space. It was here, in international waters off the coast of Brazil, that a global expedition aboard the Schmidt Ocean Institute’s research vessel Falkor (too) identified 31 new marine species in just two weeks.
The team included approximately two dozen scientists from the United States, Australia, Brazil, and Japan. Led by Dr. Karen Osborn of the Smithsonian National Museum of Natural History, the expedition focused on the poorly understood midwater zone. In this realm, many organisms undergo daily vertical migrations, rising to the surface to feed at night before retreating to the depths during the day. This movement plays a critical role in sequestering carbon into the deep ocean.
Among the discoveries were small amphipod crustaceans, a swift marine worm, nine jellyfish species, seven siphonophores, seven comb jellies, four larval appendicularians, and two species of giant Rhizaria—single-celled organisms visible to the naked eye. Many of these creatures had previously escaped scientific notice because the region had never been surveyed with such precision.
Cutting-edge technology was key to accelerating these discoveries. For the first time at sea, the Squid confocal laser microscope allowed researchers to examine the three-dimensional cellular structures of living microorganisms without the need for extensive laboratory prep. This work was further supported by advanced imaging systems, genetic analysis, and the expertise of taxonomists.
The expedition’s results underscore the depth of our ignorance regarding ocean life. According to Osborn, even in well-traveled parts of the midwater zone, countless unknown species remain that could provide new insights for biology and medicine. As these discoveries were published, news surfaced that the U.S. administration plans to reduce funding for the Ocean Observatories Initiative, a major program that monitors ocean health.
These expeditions prove that the deep ocean is far more than a simple reservoir; it is a complex, interconnected system upon which the planet’s climate and biodiversity depend. International cooperation and new technological tools are pulling back the veil on these mysteries faster than ever before.
A constantly evolving understanding of the ocean is essential for accurately assessing its role in global cycles and making sound decisions for its protection.
