The first time Ian Drysdale went diving in the Caribbean Sea to monitor reef health, the process of data collection started badly and ended even worse.

He was diving in a strong current with his wife, who started floating up and away every time she let go of the anchor line. Turns out she’d forgotten her weight belt. But the folks who collect reef data – even the newbies – tend to be a resourceful bunch.

So rather than resurfacing, they went to plan B – Ian would hold on to a section of dead reef or bare substrate with one hand and his wife Jenny’s hand with the other while she collected the data. Which worked just fine until the third or fourth spot down the reef, where Ian accidentally grabbed hold of some fire coral – an organism covered in thousands of tiny venom-filled tentacles that sting like a jellyfish upon contact. The pain served as an acute reminder about the importance of good diving etiquette on the reef.

“I let everything go,” says Drysdale, who nearly 20 years after that inauspicious start is now the Honduras Coordinator for the Healthy Reefs for Healthy People Initiative (HRI), not to mention a dive instructor with a perfect safety record. “Jenny went one way. All the data flowed the other way. Just a great introduction to monitoring reefs.”

Such is life for the underwater conservationists HRI enlists to count, measure and collect in places most people don’t see.

Melanie McField, Ian Drysdale and Marisol Rueda Flores in the Swan Islands.

Divers in a boat full of equipment prepare to collect Mesoamerican Reef data.

The data they gather is crucial for understanding the overall health of the Mesoamerican Reef, a diverse system of coral reefs located off the eastern coast of Central America and Mexico. That, in turn, helps governments and organizations prioritize actions that keep the thousands of interconnected organisms, from fish to coral to algae, in this fragile ecosystem in balance.

Despite being invisible from where people dwell on land, reef health is inextricably tied to the well-being of those humans who depend on those waters for their health and livelihoods. Protecting it is critical work that HRI’s conservationists are passionate about.

And while plenty of researchers experience data challenges, it’s safe to say these intrepid divers probably experience some of the most unusual.


The equipment divers need to collect data beneath the surface is a far cry from what their average land-dwelling counterparts use in the field.

“They walk around with their iPads and punch in some data,” HRI founder and director Melanie McField jokes.

The data-gathering tools divers use are anything but standard. Grids made of PVC pipe give the divers a measurable area. Colorful twist-ties denote distances on lead-weighted strips. Bungee cords keep pieces of equipment from snapping off in the current. And the list goes on.

As for recording the data itself? The divers learn to write their three- and four-letter species codes very small to fit as many as possible on their writing surface of choice. And when you’re bobbing around underwater, penmanship can be an issue.

Pencils (which quickly get waterlogged after a few uses) are used to write down data points on specialized waterproof paper that costs $1 per sheet. Thin acrylic slabs serve as makeshift clipboards, with the paper secured by constantly in-demand rubber bands.

Depending on the type or amount of data being collected, sometimes divers even create new equipment. One, for instance, wore a larger piece of PVC pipe over a forearm and wrote directly on it to cut out the need for paper altogether. Drysdale prefers a plastic kitchen cutting board, sanded down and hacksawed to size, that he can write directly on with a pencil.

“Everybody gets kind of creative and thinks, ‘For my particular purpose, for what data I’m collecting, I’ll fashion my own thing,’” McField says. “People are always getting stuff at the hardware store to make their own contraptions, so that’s fun.”


The divers typically work at a depth of 15 meters or less on average, though they sometimes go down as far as 20. And at shallower depths, the calm surface can belie unpredictable currents churning beneath, leaving divers feeling like they’re in a washing machine on spin cycle.

Of course, even in the calmest waters, there is still the issue of visually observing data on all the species of coral and fish.

“Usually underwater you see things bigger than they are,” says diver and HRI communications consultant Marisol Rueda Flores. “That’s why we train our eyes underwater. It’s not worth training our eyes with a ruler on land because it’s so different.”

During training, divers do lots of underwater exercises, using PVC covered in strips of electrical tape every 10 centimeters to teach their eyes what that distance looks like. They learn by trial and error, estimating from a distance and then measuring up close to see how accurate they were. Eventually, it becomes second nature.

And all this while covered head to toe in pieces of equipment clipped to their suits – plus backups for everything because once they’re below the surface, there’s no going back on board for replacements.

“We always say we look like Christmas trees,” Rueda Flores says. “You have to be a really good diver to feel comfortable with all that stuff attached to you when you fall back into the water.”

All of that equipment – whether standard-issue or DIY – needs to be washed at the end of each dive, too, or all the metal pieces will quickly rust due to all the saltwater exposure.

   Shark Tales


Equipment isn’t the only thing that’s vitally important to take care of during these challenging dives.

Being underwater as a team means being responsible for one another’s safety in an unpredictable and sometimes dangerous environment.

Across the board, HRI’s dive leaders have frightening stories of currents separating team members from one another or other mishaps that led them to fear for a diver’s safety. The need to be extremely vigilant in that regard adds yet another dimension to the complexity of underwater data gathering.

But for the divers who do this work, the challenges and the dangers are worth it – both from an environmental standpoint and a personal one.

“Once you know how to monitor a reef, you will never see a reef the same way. It’s not like I can go fun diving, and I turn off my monitoring chip,” Drysdale says. “When you’re in the middle of all this, it can be very heartbreaking. But it’s also very rewarding when things go right. Because being in conservation, it’s not about you. It’s about your fellow human beings.”




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