Featured Image Caption: Dive computers, having been invented in the 1950s but not fully accepted by the dive community until the early 1990s, are a must in modern day SCUBA and free diving. (Image Source: “Safety stop” by ChrisDag, licensed under CC BY 2.0).
Reference: Marlowe, C., Hyder, K., Sayer, M., & Kaiser, J. (2022). Citizen scientists’ dive computers resolve seasonal and interannual temperature variations in the Red Sea. Frontiers in Marine Science, 9, 976771. https://doi.org/10.3389/fmars.2022.976771
Sea temperature is one of the most frequently studied indicators of climate change. These changes don’t only affect the biodiversity that lives in the seas, but they also affect ocean circulation patterns around the world, in turn affecting human transport and economy. Measuring temperature at a large scale has been done in the past through satellite imaging, as singular climate stations can’t be everywhere and only reflect certain points throughout our ocean’s surface. Computers that help divers resurface after a dive might be able to supplement satellite imaging to give scientists a better picture of changing ocean temperatures.
Decompression sickness is one of the most serious risks taken when SCUBA diving, and it occurs after being exposed to increased pressures, as is common while SCUBA diving, for prolonged periods of time and without the proper decompression. While being exposed to increased pressure, our body stores nitrogen found in the air we breathe—which normally doesn’t pose a threat, as long as we are weaned out of this pressure slowly. On the other hand, if we have too much nitrogen in our bloodstream and we lose this increased pressure too quickly, the nitrogen gas in solution can expand and create bubbles which pose an immense risk, no matter where those bubbles end up allocated.
Before dive computers existed, divers would only take into consideration time and depth when calculating their no-decompression time with a physical dive table, that looks like the one below, leaving too much to human error and other aggravating factors that could lead to decompression sickness.
Image Caption: Dive tables, also known as Recreational Dive Planner (RDP) tables, are a good resource to plan dives where depths won’t be varying and when dive computers aren’t available. (Image Source: “GruppoSolaris.org – SSI Corso OWD – Lezione n.4 – Le tabelle decompressive” by Gruppo subacqueo Solaris, licensed under CC BY 3.0).
Now, modern-day dive computers take into consideration factors like sea temperature and previous immersions which also influence the risk of being in a dive accident. Dive computers take the human error out of a recreational dive plan and are now essential components of SCUBA diving equipment and are widely used by divers all over the world.
Dr. Celia Marlowe and their collaborators decided to use temperature information recorded by the dive computers of SCUBA divers who’ve dived in the northern Red Sea. Setting up climate stations that measure ocean temperatures in these changing times is highly limited due to the monetary investment it would entail, yet divers are in the waters day in and day out, with dive computers that automatically measure temperature and depth. And so, this group of scientists recruited citizen scientists in the form of SCUBA divers that were willing to share their dive information. They compared the minimum water temperature recorded on the dive computers and information recovered through climate stations and satellite imaging for the past 17 years for dive locations in the norther Red Sea.
So, What Did The Computers Say?
The researchers started with 323,088 anonymous data points from unknown dive computers provided by divelogs.de. These data points contained date, minimum temperature, maximum depth, and latitude and longitude. They narrowed down the measures by only taking into consideration dives within standard recreational depths (so, with a maximum dive depth of 40 meters), years with more than 75 dives per year and with a spread of dives across most months (so, dives between the years 2000 and 2017), and with minimum temperature measurements between 20 and 31 °C. After applying this filter, the researchers ended up with 9,310 usable data points.
These points showed a mean temperature of 22°C in winter and 28°C in summer with a mean maximum depth of 22.5 ± 1 meters across all months and years. Through their analyses, interannual variation and seasonal patterns in sea temperature were identified and compared to those obtained through satellite information.
And How Viable Is This New Resource?
In the end, no significant statistical difference was found between the data collected by dive computers and the data collected using climate stations and satellite imaging. Nonetheless, there will be a bias with using dive computer data, as more data points will be available for renowned diving spots as compared to other random spots in any coastal area. Dr. Marlowe and collaborators found that although there was more spatial continuity in common diving areas as comparted to areas with fewer dives and limited or no monitoring, data could still be analyzed for smaller datasets.
That is to say, dive computers could be used in the future to better understand changing ocean temperatures, making it a viable resource of environmental citizen science studies. So if you’re a SCUBA diver, gear up with a good dive computer and get ready to contribute to the world of environmental sciences—it needs us.