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by Kees Beemster Leverenz
Header image and photos courtesy of K. Leverenz unless otherwise noted.
[Ed.note: Be sure to make the jump on Leverenz’s 3D model ]
About four minutes into the dive I realized I should have listened to Faisal. Nine divers in three teams, myself included, had made it to around 40 m/130 ft when the warm calm water of the Suez gulf turned into a torrent. The thick rope that connected the surface to the wreck went from vertical to nearly horizontal, and started shaking due to the powerful water flow. With a rebreather, two decompression cylinders, and a camera, I could only make headway if I turned my scooter to its maximum speed and kicked as hard as I could. Even then, progress was slow. The wreck was 37 m/120 ft away, resting in just over 75 m/250 ft of clear blue water. We had a long way to go.
Faisal Khalaf—the proprietor of Red Sea Explorers and our deep diving guide for this trip—had told us what to expect. Perhaps “warned” is a better word. However, besides being a talented diver, Faisal is an excellent storyteller with a flair for the dramatic. This had led me to believe he was being theatrical during the dive briefing in the morning, describing surging currents underwater despite placid surface conditions. He was not exaggerating.
The flow was strong, and our three dive teams resorted to a combination of negative buoyancy, scootering, kicking, and pulling ourselves hand-over-hand down the rope to get to the wreck. As I struggled against the current, another bit of the dive briefing drifted through my head: We were less than a kilometer from one of the largest shipping lanes in the world, and it would be quite dangerous to get swept off the line. Even if a large container ship could spot a diver (they can’t), and they wanted to turn, they’d be unable to. The turning radius of a modern container ship is measured in kilometers.
Around 60 m/200 ft, the wreck came into view for the first time: an enormous hulk, with two anchors at the bow and a large twin steam boiler at the stern. Schools of giant trevallies—each over a half meter long—darted around the wreck feeding on other marine life sheltering in the hull. On that first dive, our nine divers landed somewhat ungracefully in the protection provided by the thick steel of the wreck, which acted as a break-water to shield us from the powerful current that had challenged us on the descent. We got our bearings, breathed deep, and began our dive.
Faisal believes this wreck is the remains of the three-masted steel-hulled Brazilian steam corvette SC Almirante Barroso, sunk in 1893 when it struck the rocks of Al Zait. The SC Almirante Barroso was on a training mission for Brazilian Navy Cadets, and was attempting to circumnavigate the globe when it went down. Thankfully, the crew of the SC Almirante Barroso were rescued by the English ship Dolphin, but the wreck’s exact location remains a mystery. Although the identity of this wreck has yet to be confirmed, the location, size, and type of wreck matches closely.
Imaging A Mystery
This was my first encounter with the mystery ship, a single day expedition to an exciting new wreck in the midst of my first visit to the Red Sea. It was one of the more challenging dives I’ve ever done, somewhat surprising given the generally forgiving conditions in the Red Sea. It was a lesson in the fact that cold water and poor visibility aren’t the only thing that can make a dive difficult. Our team was one of several to visit the wreck since its discovery in early February of 2018. Previous dives had focused on taking pictures, shooting video, and searching the debris for something that would confirm its identity. However, the identity of the wreck remained an open question.
A little over eight months after my first visit, Faisal invited me to come back for the 2020 Wreck Exploration Project to try to create a 3D photogrammetry model of the wreck. The 3D model would make it easier to take measurements and to share the discovery with experts, and to perhaps allow us to unravel the mystery at the bottom of the Red Sea.
For those readers unfamiliar, the process of 3D photogrammetry relies on taking high-quality photos of every bit of a wreck, each image overlapping the last. If done correctly, sophisticated software can process the images and generate a photomosaic in three dimensions. Precise measurements can be taken from this model. However, even a small gap in the chain of images can make the whole process fail.
While we had a skilled crew and a roster of talented divers for the 2020 Wreck Exploration Project, the powerful current would make the process of taking the thousands of photos necessary exceedingly difficult, perhaps even impossible. There was only one reasonable way to conquer the currents while simultaneously taking photos, and that was to mount my camera on a scooter and take pictures on the go. This wasn’t something I’d done before.
In preparation for the challenge, I consulted two friends on their equipment preferences and bought the scooter camera mount they both recommended. I had it shipped from Italy, and it was set to arrive a week prior to my departure for Egypt. I thought a week would be more than enough time to test the scooter mount. Of course, I was wrong.
When the scooter camera mount arrived, I was shocked to discover that it didn’t work with my camera’s underwater housing. The mount used metric M6 screws to secure a camera, not the imperial ¼-20 screws my housing used. An adapter plate was available, but even if I ordered it, it would never arrive in time. Thankfully I was able to call in a favor from my friend Koos DuPreez, and we spent a day at his workshop machining an adapter from scratch. Another friend, Fritz Star, was able to give me some syntactic foam to make the scooter mount neutrally buoyant. Thanks to their generous help, my gear was ready to go for the project with a whole 24 hours remaining before my flight took off!
Hail Hail The Gang’s All here
The next morning, I started the three hops necessary to get to Egypt. First from Seattle to Washington DC, then from Washington DC to Zurich, and finally from Zurich to Hurghada. I was met at the airport by a smiling man holding a sign with my name on it. He was one of the Red Sea Explorer’s staff, sent to help shuttle me through airport security and ferry me to the MV Nouran, which would be our base of operations for the week. Considering the wide array of electronics, photo gear, and dive equipment I was traveling with, as well as the challenges of navigating airport security in a foreign country, his help was most welcome. We made it through the airport, and after a short ride through town, I arrived at the dock—exhausted but eager to see if we could make it happen.
The team for this trip was originally eight strong, a small complement for the MV Nouran which could fit 24 if all her berths were filled. On arrival, I discovered that three of our divers had to drop out due to last minute complications. That shrunk our already small dive team even further. At the time of departure, the team consisted of only five divers able to safely dive the wreck: Faisal Khalaf, Kirill Egorov, Dorota Czerny, Marcus Newbold, and myself. Bernard Djermakian and Olga rounded out the team as the ship’s dive guides. While they weren’t trained to dive deep enough to reach the mystery wreck, they are both experienced divers who could act as in-water support if needed. A most welcome addition.
With such a small team and such a large boat to dive from, I immediately spread out my camera equipment on one of the MV Nouran’s four dining tables, to take stock of which pieces of dive gear survived three country’s worth of baggage handlers. I’d brought three video lights to use during the photogrammetry project. Even though I can only use two lights at a time, experience has taught me that having a spare is a good idea. Many of my diving instructors have taught me the same lesson. It was a good tip, as my quick check revealed quickly one of my three lights had broken in transit. A small but essential O-ring was protruding in a way that wouldn’t be repairable until I returned to the United States. I sent the manufacturer a message, and they confirmed what I already believed to be true: the light shouldn’t be taken in the water. I was down to the bare minimum: two lights.
The next morning, the Nouran departed with the team in high spirits and with high hopes. We wanted to waste as little time as possible, so we planned our first and second diving days to be on the mystery steamship. If all went to plan, we’d have the opportunity to dive the wreck four, maybe five times.
In addition to the mystery steamship, Faisal had secured two more leads for the Wreck Exploration Project. First, he wanted to explore a newly discovered wreck laying in 30 m/100 ft of water near an oil field. It had been scanned by a well-equipped survey ship in the area, and the wreck was definitely interesting but had never been explored. Second, he wanted to explore a pit at 95 m/310 ft near the wreck of the SS Rosalie Moller. The pit was said to contain the bow of an unknown wreck, but the only divers that had been there weren’t able to confirm anything. Of course, the team was excited by the prospects, so these two targets were added to the itinerary.
Managing Mister Murphy
On the morning of February 27, 2020, Marcus and I jumped in the water with our rebreathers, deco bottles, scooters, and my camera for our first dive of the project. Conditions were good, and currents were calm at the surface. However, we both knew the docile surface conditions betrayed nothing about the powerful flow below us. Several enormous cargo ships coasted by, carrying goods to and from Europe and Asia via the Suez Canal.
We made the short surface swim to the downline, and I decided to do a quick check of my gear before we descended, knowing that we’d incur a decompression obligation in the fight to get to the wreck itself. I examined my camera first: it was fine. My right-hand side video light also worked, and after flipping it on, it was bright even in the bright light of the midday sun. I moved to examine my left-hand side video light, and was immediately disappointed. I turned it on and I was met with several quick flashes—the death throes of the LED contained in the light—then nothing. I looked at the front of the device and discovered that its dome port was half full of salt water. It had flooded in the time it took to swim to the downline.
I shouted to Marcus about the problem and we immediately turned tail to get back to the Nouran to try to salvage our first dive of the trip. We were able to jury-rig a working light out of the corpse of the light that broke in the water and the remains of the one that broke in transit. We were back in business, in the water shortly, and on the wreck in record time.
Once we reached the bottom, I breathed a sigh of relief. After the logistical challenges and the three back-to-back flights, after all the planning and the broken lights, after the custom machining and the calling in of favors, we were here and ready to go. Blue light filtered through the deep water. Visibility was excellent. Hundreds of yellow fish were schooling around the wreck. It was time to get to work.
Marcus and I made several circuits of the wreck, doing our best to get the images we’d need for the photogrammetry model. I started the process with a circuit around the base of the wreck, making sure to capture the two anchors that lay beautifully under the bow. I then moved on to capturing the ground around the wreck, and finally I made several passes over the top of the mystery steamship, to capture the steam boilers, stove, and other debris that lay inside. The scooter-mounted camera worked beautifully, and we managed to achieve good coverage in under an hour. With our primary job complete (at least for now), we made our way back to the upline to start paying our tedious penalty for deep wreck exploration: decompression. We surfaced 202 minutes after we descended, excited to see the results of the day’s work.
In the afternoon, over lunch, I started a test run of Agisoft Metashape (the software used to create photogrammetry models). The test run was complete by dinnertime. The 3D model was more complete than I’d hoped, but less complete than I would have liked. With powerful currents running perpendicular to the wreck, staying in position was much easier on the sides of the wreck where the current was tempered by the structure of the ship itself. At the bow and stern, the weaker currents along the side of the wreck became an unobstructed flow. The sudden change in water speed makes it difficult to get the chain of images necessary for a 3D model. Despite my best efforts, the challenging conditions meant I wasn’t able to get the images I needed. The model had broken at the bow. We’d need to add more images in a subsequent dive.
The next day, the weather cooperated, and we had an opportunity to return to the wreck. Kirill and Dorota descended first, with Marcus and me following a few minutes behind. We added the pictures I believed were necessary to complete the model (and a few hundred extras, just to be sure), and then took to exploring the interior of the wreck, taking some fun pictures along the way. Sadly, we weren’t able to find anything that positively identified the wreck. We made our way back to the upline, pulled the anchor from where it’d lodged in the hull of the wreck and made the long ascent to the surface for the second time in two days.
The test processing of the model after day two showed that we’d almost certainly achieved our goal ahead of schedule. I didn’t have the computer hardware aboard necessary to complete the model, so final processing would have to wait until I returned to Seattle.
We shifted gears to explore our secondary target: the shipwreck in the oilfield. After documenting this new target, we believe it to be the wreck of an oil tender called the “Texaco Cristobal.” We also explored the pit near the SS Rosalie Moller, which was just as deep as we’d been told but far less interesting. We dubbed it the “pit of despair,” and I won’t be going back. I doubt anyone will. Although not without challenges, we’d had an extremely productive first four days of the project.
We were fortunate that the early days of the project were fruitful, as the remaining days of the project were fraught with issues. Dorota caught a bad cold, and was unable to dive for the remainder of the trip. This whittled our small dive team down to just four divers. Then (thanks to a scheduling mishap) Kirill had to depart early. He packed up and loaded his gear on a small sailboat, which took him back to port and to the Hurghada airport for his trip back home.
Our dive team was down to just three: Faisal, Marcus, and me. Fortunately, Irene Homberger was leading a trip on the Nouran’s sister-ship the Tala and was able to supplement our tiny team for a dive or two, before hopping back onto the Tala. Still, the final dives of the trip were funny: three divers diving from a ship built to comfortably accommodate 24 divers, 10 crew, and two dive guides.
We had two final dives on the mystery steamship to try to make a positive identification. Powerful winds kicked up on the second to last day, big enough to wash across the deck of the Nouran. Faisal, Marcus, and I geared up and got ready. The Nouran made several passes over the wreck, but we collectively made the decision to skip the dive. The conditions simply weren’t safe, despite the fact that the team was eager and enthusiastic to try to identify it. We dove another nearby wreck, the Ulysses, instead and were lucky enough to have a delightful encounter with an eagle ray during our dive.
Our final day of diving on the mystery steamship was safe, but uneventful. No artifacts were discovered, no markings were found, and the ship remains unidentified. The data we collected was enough to complete the 3D model. We’ve distributed the 3D model to the usual suspects: experts, researchers, and other interested individuals, but to no avail. While we still hope and believe the mystery steamship is the SC Almirante Barroso, its identity remains unknown.
We’ll just have to go back.
Here is Leverenz’s 3D model of the mystery steamship.
GUE offers a course in photogrammetry: GUE Photogrammetry.
Kees Beemster Leverenz is an enthusiastic diver and GUE instructor from Seattle, Washington, who enjoys getting in the water as often as possible. He has been deeply involved with GUE Seattle since it was founded in 2011. Currently, Kees is contributing to both local and global photogrammetry projects, as well as assisting with cave and wreck exploration projects whenever possible.
Citizen Science to The Rescue: Getting to the Bottom of Lake Tomarata
Lake Tomarata and the surrounding wetlands near Auckland, New Zealand were mistakenly believed to be low-value habitat with limited–to–no biodiversity. That’s until water quality scientist Ebi Hussain and his posse of citizen scientists took up the case and started collaborating with local partners. Here’s what a team of dedicated volunteers can do.
by Ebrahim (Ebi) Hussain
Header image: Louise Greenshields installing continuous pH and dissolved oxygen sensors. Photo by Ebi Hussain
Lake Tomarata in New Zealand’s Auckland region, is surrounded by an extensive wetland—the only one of its kind in this region. Its ecological significance and rich native biodiversity, including several threatened and endangered species, make the lake and wetland complex unique and deserving of protection. It is dangerously significant that only ten percent of New Zealand’s wetlands still exist.
A very small subset of these wetlands are considered as lacustrine wetlands, making this ecosystem critically endangered; only one percent of this wetland’s original extent remains. The lake itself is equally unique and is the only example of a peat lake system in the Auckland region. The fact that these two very rare ecosystems exist together in one place makes this site extremely special and has set the stage for our most comprehensive project to date.
Both the lake and wetland have been independently studied before, but there has been no ecosystem scale assessment that examines both systems as one interconnected environment. The wetland values are well-described in published literature. However, the ongoing pressures and impacts from the surrounding catchment are not fully understood. The lake has been monitored over time, and the general consensus is that there is limited to no biodiversity values present and the water quality is deteriorating .
Our visits to the wetland and dives in the lake alluded to something more than the degraded systems described. Instead, we uncovered a misunderstood environment with complexities that led to the false assumption that the lake had low ecological value. This highlights the value of citizen science and in particular, divers that are able to regularly document areas that most people don’t frequent.
We wanted to legitimize our findings and debunk the false portrayal of this unique environment. To do this, we wanted to create an open access integrated ecosystem management tool that could be used for collaborative monitoring and restoration. This tool would need to be based on accurate ecosystem scale assessments and integrated into a single geospatial platform where all data could be viewed and interpreted. To create this tool, we needed to map the entire environment as one ecosystem, establish an in-lake biodiversity baseline and current state assessment for both systems, integrate all the data, and develop monitoring techniques that would inform management plans.
This seemed completely unachievable for a group of volunteers, but we did not let the monumental task intimidate us. We drew up a plan, put together a team, and pushed on one step at a time.
Draw Me A Map
The first step in understanding an ecosystem is to map the environment and create a spatial platform to guide in-situ surveys and integrate multidisciplinary data. This project was the first time we mapped aquatic, terrestrial, and transitional environments to create a single ecosystem model.
The challenge with this type of mapping was that we needed to work in three dimensions because the surface and subsurface environments are interlinked. The best way to do this was to use various survey techniques and data inputs for each environment to create an integrated, three-dimensional model of the entire ecosystem.
To map the lake, we used existing hydroacoustic data collected using a variety of methods including sonar, depth sounders, and pressure transducers to create a bathymetric map of the lakebed. We used divers to ground-truth (i.e., check the accuracy of) the bathymetry, and map the shallow transitional areas between the lake edge and the wetland. The result was a high-resolution map of the lakebed and general lakebed characteristics.
We mapped the wetland using drone imagery and existing data inputs. We flew a drone along a pre-programmed geo-referenced grid that spanned the entire sub-catchment to obtain high resolution imagery. This imagery, coupled with LiDAR data, was used to create a three-dimensional point cloud, ortho mosaic, and digital elevation model of the entire sub-catchment.
We combined the surface and subsurface mapping to create a single three-dimensional model of the entire ecosystem. This gave us the ability to visualize both systems as an integrated environment and extract detailed spatial and environmental information. This model would also be used to display and integrate all the survey data. To frame this data into the context of the wider landscape, we overlaid the catchment land use split, overland flow paths, soil types, and ecosystem classification. This allowed for a greater diagnostic power when assessing the potential impacts of changes in the wider catchment.
Assessing Lake Biodiversity
The biggest knowledge gap we faced was in-lake biodiversity. There have been several reports discussing the general health of the lake and discrete ecological surveys, but no conclusive lake-wide assessments. One of the conclusions drawn by a majority of the published literature was that the lake is completely devoid of plants and is overrun by pest fish species.
We used the bathymetry to design a lake-wide survey aimed at assessing habitat quality, macrophytes, key stone species, and benthic flora and fauna. The first survey was to map out specific habitat types throughout the lake; these areas were then plotted on the three-dimensional model. We used the habitat assessments to guide the other biodiversity surveys, since they gave us an idea of where various species may occur.
During the biodiversity surveys, we made some ground-breaking discoveries. Despite the lake being classified as non-vegetated, we have mapped nearly 1 km/0.62 miles of native macrophyte beds along the southern and western ends of the lake. We also found freshwater mussel beds on the eastern side of the lake, which was an amazing discovery, as no one knew these endangered species existed here. Recently, we were lucky enough to find the first juvenile freshwater mussels ever recorded in an Auckland lake.
So far, our findings indicate that this lake is far from a barren waterbody. There are signs of natural regeneration and established populations of endangered species. It is critical that we get this message out and raise the profile of this lake: the more we know about a place, the more we value its protection.
Establishing a Baseline
A baseline state is essential to track changes over time. We wanted to take an integrated ecosystem approach to the baseline assessment rather than focusing on tracking single metrics and using them as a proxy for wider environmental health.
The first step was to use the three-dimensional model we created to define the current extent of both the wetland and lake environments. Tracking changes in extent over time provides information on wetland succession/recession, water level, lake infilling, and habitat change. We used the high-resolution drone imagery to delineate discrete vegetation types across the wetland, and we aim to calculate vegetation biomass in the future. This will allow us to track changes in vegetation assemblages in response to eutrophication, sedimentation, and climate change.
The in-lake biodiversity assessments were used to create a baseline for in-lake health. Ecological response metrics like macrophyte extent, mussel density, substrate/habitat change, and species diversity will be used as a biological sentinel network that integrates the effects of multiple impacts across the ecosystem.
Changes in water quality are pivotal to both the lake and wetland, so it is crucial that we fully understand the current state. To understand the diurnal and seasonal variation in water quality, we installed continuous water quality sensors (temperature, pH, dissolved oxygen, and light) at every meter through the water column; these sensors will log measurements every 15 minutes for a year. This data, coupled with the monthly water quality samples and climate data from the Auckland Council, will be used to create an in-lake process-based model that can be used to understand and predict lake dynamics.
We will also integrate additional data such as bird counts, pest fish surveys, and hydrological studies collected from other agencies into our assessment. This information, along with other geospatial data, can continually be added to the platform as they become available.
Tracking all these parameters creates an early warning system able to detect subtle changes in ecosystem health. This integrated response-based approach is more sensitive than traditional monitoring methods. The in-lake, process-based modelling will continue to be calibrated as we collect more data, which will eventually allow for accurate scenario testing. The end goal is to be able to detect changes early enough that we can test virtual restoration/management scenarios and implement the most effective solution before significant degradation occurs.
Management & monitoring
The key to successful ecosystem scale management is collaboration. We created an open access platform for everyone with a vested interest in this area, not only so they could use the model, but so they could also contribute their own data. We established the baseline ecosystem state—which can be referenced in all future studies—as well as the monitoring tools required to track environmental changes. The last step will be to introduce people to our work and set up collaborative working groups focused on Lake Tomarata.
Currently, we are partnered with the Auckland Council, which has regulatory authority over the area. The Council and Aotearoa Lakes have a joint monitoring and data-sharing agreement which allows both parties to benefit from pooled resources, expertise, and data. We are working with the local communities and tribes from the area to raise the profile of this ecosystem and create an interest that will hopefully lead to proactive lobbying and restoration efforts.
Our integrated ecosystem monitoring design, spatial representation of multidisciplinary data, and ability to scenario-test management options creates a publicly accessible platform for informed collaborative ecosystem monitoring and management.
What makes this effort so special is that it was all done by dedicated volunteers. This project proves that citizen science can stand up to the rigor of commercial standards and in some cases even surpass it. I hope this article will inspire you to take action despite how Herculean the task may appear to be. There is nothing more powerful than a collective of like-minded people applying themselves to a single cause.
Please visit our website Aotearoa Lakes: Citizen Science for Our Lakes for more information on our projects. Note that “Aotearoa” is the Maori (the indigenous people of NZ) name for New Zealand, literally meaning, “land of the long white cloud.”
Check out their 3D model of Lake Tomarata: Aotearoa Lakes Eco-Maps. To get to the Lake Tomarata model, click on the website maps link (above). A banner pops up along the bottom of the screen with pictures of various lakes side by side. Click on the “Tomarata Lake” site which is the 3rd box from the left on the bottom banner.
Facebook page: Aotearoa Lakes: Citizen Science For Our Lakes
Home of Project Baseline
Ebrahim (Ebi) Hussain is a water quality scientist who grew up in South Africa. As far back as he can remember, he has always wanted to scuba dive and explore the underwater world. He began diving when he was 12 years old and he has never looked back. Diving opened up a new world for him and he quickly developed a passion for aquatic ecosystems and how they work. The complexity of all the abiotic and biotic interactions fascinates him and has inspired Ebi to pursue a career in this field.
He studied aquatic ecotoxicology and zoology at university, and it was clear that Ebi wanted to spend his life studying these subsurface ecosystems and the anthropogenic stressors that impact them. After traveling to New Zealand, Ebi decided to move to this amazing country. The natural beauty drew him in, and even though there were signs of environmental degradation, there was still hope. Ebi founded Aotearoa Lakes with the goal of contributing to, preserving, and enhancing this natural beauty as well as encouraging others to get involved in actively monitoring their natural surroundings.
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