It takes a community to map the seabed
When the US Navy developed the Sonar Array Sounding System in the early 1960s, they found themselves able to map the seabed in unprecedented detail. The idea behind this early multibeam echosounder was to generate information to support submarine navigation underwater. Fast forward to 1977, and the first commercial multibeam arrived, taking pride of place on the Australian survey Vessel, the HMAS Cook. The technology has improved dramatically over the years. Today, multibeam echosounders are the backbone of hydrographic and underwater geological surveys worldwide.
Costs, space, and technical needs mean multibeam echosounders are largely the purview of research, survey, and military vessels. When the Nippon Foundation-GEBCO Seabed 2030 project launched in 2017, just six percent of the seabed had been mapped in high resolution. By May 2023, that figure reached just under 25 percent. "We've achieved a lot, but we still have quite the job ahead of us," says Jennifer Jencks, Director of the International Hydrographic Organization's (IHO) Data Centre for Digital Bathymetry.
While specialist vessels equipped with multibeam continue to contribute high-resolution seabed data, a swathe of community mappers are now helping to fill in the gaps.
Taking a collaborative approach
Recognising the importance of mapping the seabed and doing so rapidly, "the IHO was starting to become very vocal about the need for non-traditional vessels to get in the game," says Jencks. In 2015, the IHO launched the Crowdsourced Bathymetry Working Group. Its primary task was to develop and maintain the IHO Guidelines for Crowdsourced Bathymetry publication. "It involved everything – guidance on collecting the data, what you do with the data, how you get that data to a data repository and make it available for others," explains Jencks, who is also chair of the Working Group.
The Working Group includes people from multiple countries and sectors, including hydrographers, researchers, players in the maritime industry, and tech companies that make instruments. "Everyone is volunteering their time. It's fantastic," says Jencks. "We can hear first and from different nations, different maritime professionals about their struggles and needs, and we have the companies who make the instruments and software, so it gives everyone a chance to converse and talk about what needs to be done." Among those sitting on the Working Group is Katie Sheahan, Citizen Science Manager at The International SeaKeepers Society.
Empowering the crowd
Founded 25 years ago in Monaco by a group of yacht owners, SeaKeepers is a science-based non-profit promoting oceanographic research, conservation, and education. Engaging the yachting community in citizen science – also known as community science – is at the heart of SeaKeepers' activities. Alongside scientist-led expeditions, where scientists go out on a partner yacht, "we have projects that vessels can participate on their own and collect data for without having to have a science team on board," says Sheahan. Collecting bathymetric data for Seabed 2030 is one of those projects.
"Our involvement in Seabed 2030 started after COP 26 [the UN Climate Change Conference which took place in 2021], where I saw a presentation by Jamie McMichael-Phillips [Director of Seabed 2030]," says SeaKeepers' Director of International Relations Gill Rodrigues. "He was so inspirational, and I thought, this is something our members would love to support."
Vessels that want to pair up with a scientist or join a citizen science program with SeaKeepers become part of their DISCOVERY Yacht Fleet. "We have somewhere between 150 and 200 DISCOVERY Yachts all over the world, ranging from small tenders to sailboats to larger yachts," says Sheahan. For those who want to contribute to the Seabed 2030 project, all you need is a boat equipped with a depth finder and a GPS.
"Seabed 2030 have generously given us a supply of data loggers that we can install on vessels," says Sheahan. The instrument is small, connects to existing equipment and comes without cost. "Anyone who wants to get involved can. All you need to do is get in contact, and we'll fill you in on all the details and send you the logger with installation instructions, or we'll give you a hand. Then we'll keep in touch with you – make sure everything is going okay, send you a newsletter to keep you updated, and maybe feature you in a story. Then, if you decide you don't want to participate anymore, we'll collect the logger," explains Rodrigues.
So far, SeaKeepers has installed 65 loggers on Yachts. "There's always a SeaKeeper awake collecting data somewhere in the world," says Rodrigues.
Not all boats will need to install a data logger. Those equipped with navigational systems that have partnered with the IHO Data Centre for Digital Bathymetry to share anonymised data automatically collected, like Rose Point Navigation Systems, or who have dedicated data recorders that they can extract the GPS and bathymetric data from and send manually can continue to use that equipment. "It's really about all of these different flavours coming together to extend what we can achieve," says Jencks.
Practical and political realities of crowdsourcing data
When mariners learn about the Seabed 2030 project and how they can get involved, they are, for the most part, very interested. As with any project that collects data, there are sometimes concerns too. "We have had people come through and say, 'we're worried about confidentiality. We're worried about people tracking where we go," says Rodrigues. Knowing which vessel collects bathymetric data isn't necessary for the Seabed 2030 project, so SeaKeepers ensure that that information isn't shared. Some members of the commercial fishing community also have confidentiality concerns, but for different reasons. "They can be worried about providing too much information about their fishing grounds and how sharing data will affect them," says Jencks. "It's a case of listening to their concerns and working with them."
Other concerns are more of a practical nature. While, for the most part, data loggers are often relatively straightforward to install, SeaKeepers is on hand to help or do the installations for their members. Once the data logger is in place, nothing else needs to be done. Apart from sending the data, that is. "That means you're saying to someone, 'Hey, do you mind, when coming into port next, downloading and emailing this data to me?" says Jencks. SeaKeepers ask their DISCOVERY vessels to send data to them every other month, something Sheahan agrees can be "kind of tricky" to do.
"People get busy, and there's not always facilities to send the data when travelling out." New developments are about to make sharing the data much easier. SeaKeepers will soon have Wi-Fi-equipped data loggers that automatically send the data whenever a Wi-Fi connection is available. "It'll be even easier for people because then they don't have to worry about where's the memory stick, or if they will lose it or how they will upload the data to us," says Rodrigues.
Perhaps the most significant obstacle to overcome isn't about garnering data but being able to publish it. From a legislative and political perspective, "crowdsourced bathymetric data is something that's been collected since mariners first went out into the sea, but not [every nation] is on board with these data being collected and shared," says Jencks. So, while an individual citizen may collect bathymetric data in their own country's waters and then share it, "we have to respect the position of the nation [from where the data was collected]. In short, this means the data may not be used. Out of the 98 IHO member states, only 34 have stated that they are happy for crowdsourced bathymetry data to be released. Some 60 have not stated a position at all. The result – crowdsourced data collected in those member states isn't released. "In many cases, there are perceived national security issues or concerns. In others, getting a nation to take a formal position on something can be extremely slow," Jencks says.
Leveraging lower-resolution data
Since crowdsourced bathymetric data is primarily collected with single beam echosounders, the data isn't as high resolution as that collected by multibeam. "The data could be coming from somebody's fish finder, so it's not comparable to what we would get in a systematic survey with multibeam echosounders," Jencks explains. Nevertheless, the crowdsourced data is proving crucial. After all, there are many areas where there is no bathymetric data. "In those cases, a single beam measurement is better than nothing," Jencks explains. One such area is the Great Barrier Reef in Australia.
"About five years ago, Dr Robin Beaman from James Cook University in Australia won a grant [from Great Barrier Reef Foundation] to improve the map of the Great Barrier Reef [with crowdsourced data]. The Reef was only 40% mapped in detail," Jencks explains. Following a call for volunteers, Beaman installed dataloggers on eight recreational boats that regularly spend time on the Reef. By 2021, "those boats had collected some 164,000-line kilometres of crowdsourced bathymetry data. Just eight boats!" says Jencks. Alongside sharing the data with the IHO Data Centre for Digital Bathymetry, the Australian Hydrographic Office, and data logger developers TeamSurv, Beaman used the data to improve high-resolution 3D models of the Reef. Such models are essential for understanding the hydrodynamics and geodiversity of the Reef, as well as the location of different habitats that support the Reef's marine life.
Crowdsourcing, however, isn't just about mapping the gaps. It's about updating maps, too.
"Even in the United States, we have nautical charts that haven't been updated since the 1920s, 1940s," says Jencks. While single-beam bathymetric data is likely to be more accurate than the plumb-line (lines with weights) measurements that make up the data in some areas, Jencks says that one of the key benefits crowdsourced bathymetry brings is prioritising areas for multibeam mapping. "We can't do everything, but we can compare crowdsourced data to our older chart. Sometimes, the numbers look pretty similar, but other times we find discrepancies. So, if we can only go to [map] one location, we better go to the area with the discrepancies."
Data is also needed in areas where mapping is more up-to-date. "The coastal areas of the US, for example, are seeing a lot of change, but without regularly mapping those areas, we won't know what those changes are or how quickly they are taking place," Sheahan explains. With data from the Royal National Lifeboat Institute in the UK, for example, "we're able to look at how the coastlines are changing, how sandbanks are shifting. We wouldn't be able to do that without their data," says Rodrigues.
Perhaps just as important, not all benefits are necessarily about mapping the seabed itself. "Most people on the water have a love for the ocean," says Rodrigues. "They know there are problems, and they want to help. Everyone knows that we can't protect what we don't know, so by the very nature of this project, they know they are helping, doing something constructive, and that they are part of something bigger."
This story was written for Seabed 2030
