“Every time we look in the deep sea, we discover something new.” José Carlos Hernández, Professor of Zoology at Universidad de La Laguna, explains the importance of working together to explore our deep seas.
At the University of La Laguna in Tenerife, Dr José Carlos Hernández has several things on his mind: sea urchins, climate change, and ocean acidification. “I have studied sea urchins since my PhD, and I’ve worked on climate change and how that impacts sea urchins and macroalgal beds. I’m also working on ocean acidification and carbon seeps here in the Canary Islands.”
As part of the ongoing Macaronesia Tenerife Submersible and Diver Expedition, six of Hernández’s students will help the team to identify some of the myriad marine life in the waters around Tenerife. “They’ll be working with some of the best taxonomists, so it’s a really good opportunity for them,” says Hernández. The students will work on samples collected by the Pisces VI class submersible in the Radazul area, where the water reaches depths of 300 metres, and those collected in shallower waters by the Finnish Scientific Dive Academy. “The students will be separating all the meiofauna and macrofauna brought up in the samples, then with experts will go through all the organisms and try to identify them.”
Even though the sampling will take place in some areas that have been surveyed before, Hernández expects that the work will lead to the discovery of new species. “It’s a good thing that we will have the organism and not just photographs for accurate identification,” says Hernández. “Without a specimen, it’s impossible to get the details needed to describe a species, including its DNA.” Once identified, the specimens will be added to a collection held at Spain’s Museo de Naturaleza y Arqueología de Tenerife, allowing future researchers to examine and compare them to any organisms they themselves might find.
Supporting Policies for a Sustainable Future
Mounting expeditions to study life on the sea floor in shallow waters, let alone into deeper areas, is not something that can be done on a whim. “Ocean Census is a really unique opportunity for us to bring together lots of experts and work together,” says Hernández. “This opportunity isn’t just something that will benefit the scientific community or those curious about marine life”, Hernández adds. “It’s essential for understanding the ocean and developing policies, such as those that may arise out of COP 28 – the United Nations Climate Change Conference, to ensure a sustainable and resilient future for us.”
“Everything is connected in the sea,” Hernández says. “One of the characteristics of marine life is that they spend different parts of their life cycle in different habitats. For example, in shallow waters, the larvae [of some species] drift on currents and settle in tidepools. Then, when they are grown, they move to deeper waters. Here in the Canary Islands, below 40 metres, there are areas full of black corals, providing habitat for fishes that spend part of their life down there, that we then fish.”
Hernández notes it’s also important to recognise that we can’t protect what we don’t know. Indeed, there is a lot we don’t know about the ocean and the deep sea in particular. “Every time we look in the deep sea, we discover something new,” says Hernández. Among the most grandiose of those discoveries are hydrothermal vents. “In the 1970s, we discovered this whole new ecosystem based on chemical reactions, not on light. It’s like looking back on Earth’s history when the Earth was filled with volcanoes and gasses. Maybe life was coming out of environments just like these.” “What else is there in the sea that we don’t know? This is why we need to go into the ocean and collect data. We can’t act on what we don’t know.”
COP28: An Opportunity to Address the Most Insidious Threat
Today, the need for knowledge and data has never been more important. “It’s sad to say, but every environment nowadays is under threat,” says Hernández. “We find trash everywhere. We have fishing gear that can go deeper and that is more aggressive than before. Particularly in the deep sea, where these environments are very susceptible to damage. The corals, for example, are very fragile, and most have been growing there for millennia. When we damage these environments, they don’t recover quickly.”
Perhaps the most insidious of human impacts comes from climate change. “In the Mediterranean, we’ve seen extensive coral mass mortalities due to ocean warming. I think this year was one of the worst,” says Hernández. Although ocean warming is slower in deeper waters, “we are seeing it more and more every year,” Hernández adds.
Ocean warming brings with it a whole set of changes. Warmer waters, for example, hold less oxygen than colder waters. In areas along the coast where fertilisers run off the land into the sea, or untreated sewage flows out, algae can form massive blooms that are sometimes toxic. Warming waters are directly related to rising sea levels and may result in more intense hurricanes and cyclones. In combination with climate change’s “evil twin,” ocean acidification (caused by our carbon dioxide emissions), the biochemistry of the ocean is already changing in some places. In an effort to stay in hospitable environments, marine life is already shifting, but not all will be able to move as fast as the ocean is changing.
Hernández hopes that as a result of COP 28, the World’s Governments will take meaningful action to reverse our greenhouse gas emissions and combat climate change. “All these things happening in the ocean because of us…they impact us,” says Hernández, highlighting how sea level rise is already a significant issue for many small island nations such as the Solomon Islands and that climate change is putting an additional strain on already depleted fisheries resources in some countries like Senegal.
“Many services that we use today – for food, for pharmacy, for regulating our climate, come from the ocean, and they are at risk. People are already suffering, and we will see more of that…we really don’t know how this biosphere works, but we are destroying it. How do we expect to survive in this future environment that we are creating?”
The ongoing 21-day Macaronesia expedition is being co-delivered in partnership with the Jesús Ortea Research Group, Museo de Ciencias Naturales de Tenerife (MUNA), Universidad de La Laguna (ECOMAR), and Instituto Español de Oceanografía (IEO).
Specialists in ocean species discovery around the world are being urged to sign up to the Ocean Census Science Network to help support the mission to accelerate species discovery.