Seamounts of the GalapagosLatest update July 16, 2019 Started on October 11, 2018
Hiding beneath the sea surface of the Galapagos Marine Reserve lie hundreds of underwater volcanic structures known as seamounts. They are too deep to study by scuba diving, so little is known about their habitats. This November 2018 scientists will be use a remotely operated vehicle to explore several uncharted seamounts. Will these structures be biodiversity hotspots or barren moonscapes? Will we find undescribed reef ecosystems? Discover new fish communities or identify critters never seen before? Follow along to find out!
The day we discovered unknown kelp beds in the Galapagos
What was meant to be our final day in the field exploring seamounts with VideoRay's ROV, was by far the most exciting one (and not the last, read on!). Bajo San Luis was the last seamount on our list and finding it wasn’t easy as our coordinates did not match those of the captain, who apparently knew the site well. We also had difficulty locating the summit because our depth gage had stopped working, a typical technological failure! But luck seemed to be on our side – having weighed up the pros and cons of lowering the ROV to look for the summit – we landed right on top of it at a depth of 50m. As the ROV approached the seafloor of what appeared to be a table top summit, we stared at the screen in amazement as we began to make out tall, long, brown green algae waving at us in the swell. It was clear that the algae couldn’t be anything other than KELP! This was such a surprising find, as the only known kelp species in the Galapagos has so far been found in the cold and nutrient rich waters that dominate the west of the Archipelago. And here, in the central region of the Galapagos, we were seeing kelp at a depth between 40 and 70m (technically known as the mesophotic zone because of the lower amount of light that reaches these depths) growing at the very limit of where they can photosynthesize. The reason they survive here is likely due to the colder temperatures and high nutrients found at these depths (something I’m very interested in investigating further). Taking a closer look at the kelp forest, we came to the shocking realization that the kelp we were observing looked very different from the recorded species E. galapagensis and that we might possibly have discovered a new species for the Galapagos. Aware that this might even represent a ground-breaking discovery, we embarked on one final mission the following day with the goal of collecting two kelp specimen samples. The night before, Tom and Andy amazingly engineered a robotic claw onto the Pro5 ROV. We were all on tenterhooks about the possibility of being able to grab a specimen by the stipe (“stem” of the kelp), so that we could inspect it more thoroughly in the lab. While at first it was tricky for the pilot to get the ROV close to the kelp in the strong currents, with some patience we managed to collect two beautiful sample specimens, which the team was very proud of! Since the day we found the kelp forest, a myriad of questions have been running through our minds. How many more forests are out there in the reserve? What species is this? Is it new for the Galapagos? Is it new to science? What’s the influence of the seamounts on these ecosystems? And what marine species does this kelp forest support? Stay tuned as we address some of these questions in blogs soon to come.
On our third exploration day we headed to Roca Sin Nombre, or Nameless Rock in English. Technically this site was not a seamount, as its tip breaches the sea surface, so instead it’s a rocky outcrop or mini island. Nonetheless the marine habitas along the mesophotic zone (40-200m depth) on its slopes should resemble that of seamounts. As the captain predicted, currents around the Nameless Rock were strong, so we aimed to do the exploring on the leigh side to avoid drifting. But even on the leigh side the currents drifted us, so piloting of the ROV was challenging, as the boat and tether would drift northward often yanking the ROV backwards during the transects. To reduce this effects, the captain carefully manoeuvred the boat to keep it over the ROV, whilst also trying to keep the tether safe from the propellors. After a few “tests” (dives gone wrong!) we figured out a strategy that involved a lot loud communicating between the ROV pilot, tether handlers and captain, enabling us to successfully undertake video transects at the four different depth zones.
Between 40-60m deep we found the rocky and steep seafloor beaming with fish and soft coral and sponge gardens, predominated by black corals. See second image below – the black coral is actually the yellow-greenish bushy-looking corals. The fish community was similar to that found on shallow reefs (10-20m), included the colourful reef fish, sharks as well as important commercial species such as groupers and snappers.
As we lowered to the 70-90m depth zone, the seafloor gradient flattened, and at first glance seemed lifeless. However most of the rocks at this depth were actually covered with microflora and fauna. Principally encrusting coralline red algae (see third photo), which like corals deposits calcium carbonate. We also saw quite a few scorpion fish squatting on the seafloor, and ran into schools of fish such as "blanquillo" (see last Photo), which locally is an important commercially fish species. In the deeper sites, we encountered similar landscapes but darker, where we also observed quite a few interesting looking tubelike sponges.
In #Galapagos you will see lots of mottled scorpionfish(Pontinus clemensi)at markets&restaurants,but not snorkelling,as they live between 80-200m deep.Finally got to see them in their natural habitat during our ROV seamount explorations trips https://t.co/awxi2WWgS9 @DarwinFound pic.twitter.com/zI6LhqppCV— Salome Buglass (@BugSalome) March 20, 2019
Our first field trip turned out to be a very critical test day for all of us, requiring some ad hoc decisions to say the least. We chose to work with a small fishing boat, not only because of the affordable price, but also because the captain was experienced and knew the seamounts we wanted to visit. The 7 of us and all our gear (ROV, tether, generator, food etc.) just about fit on it. However, things soon started to get very tricky when it came to operating the ROV, which involved running a generator to power the control panel and ROV via a 300-m-long tether that was not easy to manage in the crowded space . This was all before the waves started to grow! Staying dry was not an easy task, and there was even a moment the generator was almost swept off board (now we all laugh at that moment, and it will stay as one of the most memorable ones for us all!). But taking heed of the captain’s comment that “this is not even close to a choppy day,” it was clear that we needed to upgrade to a larger boat. This was a tough decision for the team, as a bigger vessel costs significantly more, meaning we could afford fewer field trips -- but it was for the best. Thankfully, the VideoRay team committed to funding a field trip, giving us 3 days to “safely” explore and survey seamounts.
The first day on the new vessel was amazing. We headed towards Floreana Island, as next to it lies the locally famous underwater table mountain Bajo Hancock (named after Allan Hancock, an oil tycoon from the 1930s who funded and sailed many key marine expeditions in the Galapagos). The ROV operation ran smoothly and we successfully got to explore this seamount from head to toe. As you can see on the photo, there was enough space to even bring the tether-frame I built with Salome (see our first post), which made a huge difference when it came to managing the tether and stop it from tangling.
Our dives started at the foot of Hancock, where we sent the ROV down to 180 m – the max depth for the stereo-video system. At first, in the deep and dark we saw lots of unexciting gooey sediment, and then boom, we found them - deep sea sponges and coral reefs and a myriad of interesting fish and invertebrates living amongst them. Bajo Hancock was the largest and deepest seamount we were going to explore. Given that this seamount’s diameter extends over 20km we had to do several dives in order to survey it at various depth intervals. As we made our way to the summit, we knew we were getting closer, because we could make out seabirds (see photo) and what seemed like schools of tuna having a party feeding on fish balls. This was no surprise to us, because seamounts act as obstacles that divert deep-water and often nutrient rich waters upwards into the photic zone, giving rise to micro-algae blooms, which are the basis of food chains for many fisheries. On the summit itself through the ROV we observed big schools of fish swimming in the middle of black corals and sponges (see photo), and spotted small invertebrates that have also made this seamount their home
At last the field (sea) expeditions start! With the help of a local fisherman and his vessel, our team headed off for the first seamount, “El Bajo de Santa Fe”. Despite some technical difficulties with the generator powering the ROV, we managed to find the summit, which turned out to be a lush, black coral garden packed with creole fish
As the team’s lensman, I was keen to finally get some shots of the ROV in action. So, as the ROV was lowered into the water, I jumped in to capture some images of our underwater eye, the Defender, before it disappeared into the deep.
The gear is here... so let the fun (work) begin! Finally, I got to see and touch Videoray’s ROVs, which I have written about endlessly in the methodology sections of proposals I put together over the last year. Well worth it! After Tom and Andy took us through a fascinating description of how the gear works inside and out, which included an “open heart surgery”of each ROV, to show us what moves what, we took them for a swim at the dock and the marine labs of the Charles Darwin Research Centre. The goal was to get all the gear tested, make sure it was optimally configured, especially with the new stereo video system attached to it. I even got to “fly” the ROV myself using the joy stick on the compact control console --it's like playing a video game but for science. Watching the ROV zoom around, dive under and up again, and seeing the live video footage, I realized that the expedition was finally going to happen, that we really are going to explore some uncharted seamounts in the Galapagos!
The team is complete!
The VideoRay crew and the ROVs smoothly sailed through customs and they are finally here on the Enchanted Islands. Even though it's the first time we have all met in person, after all the skype and whatsapp conferencing and chatting, it felt like we were meeting old friends.
Another major challenge has been finding the right generator: powerful enough to power the Defender ROV, yet compact enough to fit on our small, but slick fishing boat (white and green vessel in the pics). After a desperate last minute search, we found one that we hope is perfect -- the sea lions certainly thought so! We will find out tomorrow on our dry run when we test the gear (and the team). So fingers crossed.
Meanwhile in Philli, our other half of the team are also getting ready. In the photos below you can see the VideoRay crew doing last minute tweaks to the ROVs in their labs. The seven-strong team of ROV engineers and pilots will soon be joining us in the Galapagos with their Defender and Pro5 ROVs.
In addition they will be bringing a stereo-video set (first image on the left) that was sent to us by our collaborators from Curtin University. This dual camera system, attached to the ROV, will enable us to undertake video transects with a 3D perspective, enabling us to count and measure the size of fish and other critters with very high accuracy. Bon voyage, and fingers crossed that customs won’t give us trouble with all the excess luggage packed with high-tech gear!
When you want to do research in a remote world-famous heritage site such as the Galapagos Marine Reserve, it definitely takes some solid logistics not to mention paper work. The planning phase kicked off back in June, when we learned that we got the funding to this project, and since it’s been nonstop -- set dates, book flights, get research permits, science visas, gather equipment, find a boat, do safety plans…Oh and also build a team! Alize, the project’s science intern arrived from France last week, and Joshua, local photographer/filmmaker from Galapagos, has already started documenting the prepping stage (his pics below).
Being based in the Galapagos, specifically in Puerto Ayora, the biggest town in the archipelago has made the undertaking of logistics in this short amount time possible. Despite being almost 1000 km (~600 miles) away from the mainland, this island town has a population of over 20,000 people, thanks to the booming tourism industry, and with it lost of supermarkets, hardware stores and boats. Thus, we have been able to get almost everything we need for the expedition right here, with one major exception, the ROV and its special add-ons! But thankfully the other half of the team, the VideoRay crew from Philadelphia, will soon be joining us here bringing their Defender and Pro5 ROVs. Field work kicks off in 3 days, and we are almost ready! “Minor” equipment construction is still taking place, such as building a tether-frame. This contraption will hold the 400 meters of cable that will power the ROVs all the way down to the shallow seamounts. Photos by Joshua Vela
Owing to the active volcanic history of the Galapagos archipelago, hundreds of underwater mountains, called seamounts, rise hundreds to thousands of meters from the sea floor. These topographical structures are known to deflect ocean currents and foster physical, chemical and biological interactions between the seafloor and the waters above. Thus, seamounts often host rich biodiversity and productive habitats, such as cold-water reefs, and support numerous fisheries. Given the technological/financial challenges of studying deep-water systems, little is known about the life and physical environments of Galapagos seamounts.
In the Galapagos many key fishing sites for the local artisanal fishing fleet are above shallow seamounts, locally known as “bajos”. A key characteristic of the bajos is that they protrude into the light or euphotic zone of the ocean. Thus, they likely host mesophotic (middle of the light zone) reefs, which are very understudied ecosystems in the region. Currently, scant scientific information exists on these shallow seamount habitats and their associated flora and fauna, and even less about their vulnerability to fishing.
With the aim of closing this knowledge gap scientist from the Charles Darwin Foundation in collaboration with Galapagos National Park Directorate and remotely operated vehicle (ROV) manufacturer VideoRay, are undertaking an expedition to explore these shallow seamounts. To this end we will deploy a new generation of small commercial ROVs that can reach a depth of 350m to carry out a baseline study to assess shallow seamount habitats and their fish communities. The main goals are to (1) characterize the benthic habitat and fish communities of shallow seamounts, and (2) increase knowledge and understanding of these understudied ecosystems for Galapagos Marine Reserve (GMR) decision makers, the local and scientific community, and the general public.
The plan is to survey four shallow seamounts in the central eastern region of the GMR by the end of November 2018. In a small fishing boat (10-m-long powerboat) we will navigate to each seamount site, lower the ROV into the water, then undertake horizontal video transects with the ROV along different depth gradients. Each video transect will be analyzed to assess the biodiversity and build inventories, as well as to determine the distribution of different species and communities across depths and seamounts. We believe this information is essential for improving the management of sustainable fishing practices and the protection of these understudied habitats in the GMR.
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