Partner: Fugro
Coral reefs are sometimes called the rainforests of the oceans and support an estimated 25% of all known marine species, but they, and the sponges that inhabit them, are unusually susceptible to changes in the waters and the local microbial community. Coral bleaching is just one of the negative effects of changing world.
However, teams from a Brazilian University have launched a project to learn more about the bacteria from different regions and different species. They hope to produce a probiotic cocktail and help troubled ecosystems to recover.
Diverse and fragile
It was an expedition, undertaken about 150km off the coast of Rio De Janeiro in Brazil, which aimed to take samples of coral, sponges and seawater to better understand more of these diverse but fragile environments. This expedition required the expertise of Brazilian scientists supported by international experts and it required the ROV (remotely operated vehicle) and offshore skills from Fugro Brazil… and it required their flagship vessel, the Fugro Aquarius, to be kitted out with a special laboratory to preserve the collected samples long enough for study.
Raquel Peixoto is an expert on corals, and a lead on the project. She is Professor of Marine Science at the King Abdullah University of Science and Technology (KAUST) in Saudi Arabia. The project began while Raquel was at the Federal University of Rio de Janeiro, and that is still the leading institution.
“Corals are holobionts,” says Peixoto. “Which means that they are the host and associated microbiome that they rely on. And together they develop the biological processes that the organism needs to survive and unbalanced relationships between corals and the associated microbiomes can generate disease, bleaching, mortality and these things that we’ve been seeing in the world.
“Shallow coral reefs have been threatened by thermal bleaching events that are caused by increased CO2 emissions in our atmosphere that actually ends up creating this anomaly. Increased seawater temperatures and back-to-back events don’t allow corals to recover, and because of that they’ve been dying.”
When the temperature rises, the algae starts to produce large amounts of ‘Reactive Oxygen Species’. Which are toxic for both the corals and the associated microbiome, so the coral expels the algae. As the algae leaves, 90% of the energy for the coral is lost (and the colour disappears, hence the bleaching effect).
Once the temperature is back to normal, if the coral is still alive, the ecosystem can recover. But the problem is that these events can be so long or severe that the corals die before the algae can return.
“And this has been happening more frequently. So, this is one example on how these symbiotic relationships are affected. And why corals die because of that,” says Peixoto.
The same thing can happen with increased temperatures in the deep sea, for the deeper corals. Pollutants, pathogens and acidication can all cause this imbalance.
“And our goal is to understand how these symbiotic relationships are affected by different types of stress and mechanisms for us to restore this microbiome,” says Peixoto. “That means to use the beneficial ones and apply them back in a way that we can retain the functional organism and an improve boosts their health in a way that they can resist different impacts.”
A natural water filter
Torsten Thomas is a Professor of Marine Microbiology at the University of New South Wales in Sydney. He has a special love for sponges.
“The reason I’m actually interested in them is because there are such ancient organisms,” says Thomas. “So in the evolution of multicellular organisms as we go from archaea and unicellular organisms, to more complex organisms. What we call multicellular organisms. Sponges were probably the first stage of that evolutionary process, or at least the ancestor of sponges were the first evolutionary step there.”
Very early on in this development of multicellular organisms, a symbiosis was being created. Various organisms working together, allowing for the development of increasingly complex organisms. These symbiotic interactions worked to allow for the development of increasingly complex organisms, and some persisted all the way to modern humans.
“And as you probably know, we have many, many bacteria that are microorganisms that live on our body, and in our body in our goods, guts. And so there’s a lot of similarities there in in the mechanisms involved.”
Sponges themselves persist today, and are found in most tropical and temperate marine ecosystems. Often they live on corals, sometimes on coral rubble. And in these environments they play a number of important roles.
“Firstly, they provide structure on the surface of the marine environments. So they basically function like nurseries for fish and other sort of invertebrates and little creatures,” says Thomas. And they also have the ability to take up a lot of nutrients and organic matter from the water column.”
In this way they clean and filter the water and make the nutrients available for other grazing organisms, such as fish which eat the sponge as it grows.
“They also have interesting applications for pharmaceutical purposes,” says Thomas. “Sponges are well known for many things. They contain a lot of interesting chemical compounds, secondary metabolites that have applications in things like cancer treatments or other sort of medical treatments.”
Just like coral, sponges are highly sensitive to changes in the marine environment. This is because they pump an enormous amount of water through their bodies. A small, fist-sized sponge can filter 1,000 litres of water through its body every day. This makes them very sensitive bio-indicators as they can concentrate things from the water column into their bodies.
Sponges are probably not as well studied as corals, and the diseases they develop are less-well understood, but there are diseases. Torsten mentioned that sponges have seen a lot of changes in their time on the planet, but these changes have typically happened very slowly. How well sponges can cope with rapid environmental changes is currently being studied.
“And I still think that probably sponges are quite well equipped for those changes, but probably there’s also a threshold where change is so dramatic and so severe that they won’t be able to cope with it,” says Thomas.
The Aquarius sets sail
The team wanted to investigate the microbiome associated with corals and sponges, both shallow and deep sea, to understand the interactions and beneficial functions. If they could manipulate the bacteria from different regions and different species, it may be possible to produce a probiotic cocktail and help troubled ecosystems to recover. But before the team could embark on the mission to cure the world’s coral, the samples needed to be collected. And that meant offshore, deep-water operations.
Yasmin Sodre is an industrial engineer with an MBA in the oil and gas energy transition. She works in the Fugro Brazil Commercial Department as a Proposal Coordinator. Sodre basically works to accurately predict the cost, size and duration of Fugro’s future projects in Brazil, to ensure their successful execution.
But this project was different from the normal work of site characterisation and asset maintenance monitoring. It was a Brazilian university project. Although it was in fact sponsored by Shell Brazil Technology. Shell has a research and development programme which looks for relevant research initiatives to sponsor.
The project had faced many challenges in the past related to the offshore expedition. This time, stars (and project schedules) aligned and Fugro Brazil’s flagship Aquarius vessel put out to sea.
This is an 83m-long vessel with a deck area of 520 square metres and accommodation for 60 people. It has two ROVs that can operate in water depths down to 3,000m. It bristles with winches, communications, a helipad… and, unusually, it put out to sea with Sodre on board.
“Oh my God, it was quite an experience. I wanted to go, but was also asked by my line manager and the Country Manager. This project was special to us because it was to help the scientific community to conserve deep sea reefs around the globe.”
Sodre says that the project clearly aligns with all of the ongoing work elsewhere in the world for the Decade of Ocean Science. She is also from a younger generation that wants to do meaningful things to help the planet.
The vessel had an unusually large contingent of scientists, and so it was also an unusually diverse mix of people for an offshore operation. The Remotely Operated Vehicle (ROV) team, the deck team, and 15 researchers from the laboratory side.
Sodre’s role was to support the project manager and the offshore manager, working as the interface between her company and the scientists.
“Basically, the project was focused to collect corals, sponges, water and sediments, okay. This sample they were collected around 600 to 800m water depth, and around 100 kilometres from the coast,” says Sodre.
They had to prepare the vessel for the expedition in just three days. Three days to turn the Fugro Aquarius into a floating science facility.
They had to install a bio-box below the ROV to enable live sample recovery, and also had to construct an environmental laboratory. They also had to install 12,000 litres of tanks on the deck to maintain the samples at constant conditions, otherwise they might degrade before getting to the permanent laboratories of the Rio Aquarium, purpose built for the project.
“We were taking water from the deep to store the samples in their natural conditions, this was done via a pipe. It was very unusual.”
All in all the expedition lasted 10 days in August 2021, performed more than 100 ROV dive hours and collected more than 150 samples, far more than the 15 or so that the scientists hoped for.
“Their eyes were shining, I couldn’t be more happy about the success of that,” says Sodre.
One tense moment was when a winch-operated soil grabber failed to work, but the team had such a diversity of skills that someone managed to design an ROV-operated grabber within the space of six hours.
But the most challenging aspect of the entire expedition from a technical perspective was that three-day pre-mobilisation work, making sure that everything was coordinated and all of the on-board equipment would function together.
Global support
Another unusual feature of this project was the need for realtime video contact with Raquel and Torsten, who could not be on board the Fugro Aquarius. Fortunately remote operations are not unusual in the offshore sector and the technology and the experience was there, which allowed them to watch the sample collection in real time.
The expedition has been over for half a year but is already causing excitement in the scientific community. Peixoto explains, “We already have some very cool results from these expedition with Fugro. We already know that there is a very interesting microbiome associated with these corals, we already know that we isolated several potential new bacterial species, even macro species, it looks like.”
Thomas is himself still in the process of examining nine of the sponges, some of which appear to be completely new species, there’s a lot still to explore in the deep ocean.
Peixoto says, “But we are also trying to understand how the microbiome responds to different abiotic conditions in this ecosystem. We already know from the first experiments that it looks like the recovery is accelerated, the recovery of these corals is accelerated by the inoculation of probiotics. So we already know a few things, we already have some preliminary results, but we should be able to report the first key results by November [2022].”
Thomas adds, “This was my first deep sea expedition. And just seeing the images of that particular environment… you can study it theoretically but it is important to get a feel for it. The weather conditions were ideal and the team worked really well, so we got loads of samples. And we really haven’t scratched the surface of the samples that we took, we have freezers full with samples.
“So it’s going to be years, and if not even decades of studying that we can do. And what we found so far is all very exciting, and some of the work really supports our hypothesis, that that those microbes that are living on corals and sponges are quite important, they have the ability, for example, to fix CO2, and bring their carbon and energy into this ecosystem.”
Peixoto concludes, “I think one thing that was very important and unique about this expedition is that we really worked together with the Fugro team to develop the best possible laboratory on the ship as well. So on top of collecting these animals using very cutting edge technologies and keeping these corals and organisms alive on the boat, we also managed to isolate bacteria on board. So this makes a lot of difference when we compare bringing the samples back to the lab, and then starting the process of culturing these bacteria. So we can say that we had fresh samples and some bacteria that would be done. By the time we get back to the lab, we’re still viable. So we think that that made a huge difference on time in terms of the diversity that we’ve managed to isolate to culture from this expedition.”
