In November 2023, the first expedition of The Nippon Foundation-Nekton Ocean Census program, a new initiative to accelerate the discovery of species in the ocean, began in Tenerife. The expedition brought together experienced and early career scientists specialized in studying species classification (taxonomists). It is remarkable that only an estimated 10%–25% of marine species have been described, life that is the legacy of four billion years of evolution in the ocean. These species form the complex jigsaw puzzle of life that creates marine ecosystems, allowing them to function and provide vital services to humankind, such as food provision, waste recycling, and critical new medicines fighting cancer, infections, and heart disease.
Litmus Test
Tenerife was a significant test for the Ocean Census program. Scientists have been studying the life of the Canary Islands for more than 150 years, so it could have been the case that the biota was well known. Deploying a range of sampling technologies, from snorkeling and SCUBA diving to deep-diving technical divers and a submersible, Pisces VI, the international team of scientists collected corals, sponges, seaweeds, and other marine life as well as samples of sand and brushings from the seafloor.
Pisces VI was built in Canada in the 1970s and used for government contracts for torpedo retrieval and then by the oil and gas industry. Following an extensive rebuild in 2015, the submersible is now used for ocean science. Ocean Census scientists used the submersible to search the seafloor for life down to 250 m depth off the port of Radazul on the southeast coast of Tenerife. Twilight zone coral gardens were encountered with bright yellow and orange corals and sponges ranging from reds and purples to intense blue.
Technical divers from the Finnish Scientific Diving Academy visited sites on the southern and western coasts of Tenerife. The divers employed the latest computer-controlled mixed-gas rebreathers—systems that scrub CO2 from their exhaled gases and recirculate them—allowing them to dive to great depths and for extended durations. They also employed a range of tools for sampling the environment, including an airlift to suck up sediment, like an underwater vacuum cleaner, brushes to sweep delicate and small marine animals from the seafloor, and tubes to take samples of sand and silt. They sampled on the seafloor from around and underneath rocks and in caves assumed to be the remains of lava tubes emanating from Tenerife’s past history of eruptions.
Biodiverse Findings
Back on land, our teams of scientists eagerly awaited samples to arrive, swarming around the submersible when it was lifted from Radazul harbor or picking through the fine-meshed sample bags delivered by the divers. What they found was astonishing: new species of snails, new shrimps, and strange worms carrying colonies of bacteria with which they shared a symbiotic relationship. Other animals will require further investigation following the expedition but include potentially new species of corals, flatworms, and sponges. Some of the animals will look familiar, such as bright yellow sea fans or snails, but others appear almost alien, like a worm-like animal covered in what looked like fish scales but which turned out to be a primitive mollusk.
Daniela Zeppilli, Meiofauna Lead and Taxonomist from IFREMER examines meiofauna from the expedition. (Image credit: Ocean Census)
To our surprise, more than 30 potential new species have been discovered, with some being fully described within 36 hours of collection. Further investigations are likely to double or even triple this number of new species. To the Ocean Census program if so many new species have been found at a locality where research has been undertaken for 150 years, then we will likely discover hundreds or even thousands of new species at poorly studied localities globally. We know that shallow waters are the best studied, so moving away from land and into deep water, we are likely to recover many previously unknown species.
What is notable about the new species discovered in Tenerife is that many of them are small. Biological diversity is almost fractal in nature; the closer you look, and at a smaller scale, the more species are found. It raises intriguing questions about current scientific estimates of 1–2 million species living in the ocean. This was not in every case, however, as some of the corals and sponges were large animals, easily seen by the divers or from the submersible. These are so-called megafauna.
The Nippon Foundation-Nekton Ocean Census Expedition has produced exciting results. Still, more than anything else, it holds great promise for the discovery of marine life in coming expeditions to the Bounty Trough in New Zealand and to the Arctic. At a time when many marine species and ecosystems are in decline due to overfishing, pollution, and climate change, this work is crucially important. To protect marine life, we must understand where it lives in the ocean. Where we are too late, and species are on a spiral of decline towards extinction, it is important for future generations that they are documented, and their legacy preserved.
To find out more about Ocean Census, visit: oceancensus.org
This feature appeared in Environment, Coastal & Offshore (ECO) Magazine’s 2024 Spring edition Marine Exploration, to read more access the magazine here.
