Eye to Eye

08.22.17

Sun rays diffused through the glassy water, casting a buttercup-yellow glow across its surface that made the surrounding icebergs look ghostly white in comparison. Our research vessel was bathed in warm light as it glided through Baffin Bay, silent besides the slosh of waves against its sides.

We were headed back toward the fishing lines we set up at the bottom of the bay that morning. The longlines extended yards across and had nine hooks dispersed throughout it. Fishermen around here had told us that they used longlines with five times as many hooks to catch the large halibut that rippled along the bottom of the ocean, but for our purposes, just nine hooks was more than enough — any more, and we’d be in trouble. At first, I was a little surprised that this was the research group’s method of choice, but I realized after boarding the vessel that I had never thought very deeply about how scientists find and interact with large sea creatures to begin with.

The vessel squealed to a stop as we reached our site. Two of our certified divers, suited up and ready, dropped off the ship with waterproof cameras in hand. A few minutes later, the live feed flickered to life up on the deck, and I saw them descending in the direction of the longline, which tumbled in circles with the movement of a large mass attached somewhere. We followed the longline toward the source of the motion and were met with the same mottled skin I saw years ago, only this time it was encircled in the thin fishing line. Its torpedo-shaped body tapered into a sweeping tail that made its front fins look tiny in comparison. The divers floated a few feet away from the shark, silently assessing how to safely bring it to the surface for a closer look.

Before I knew it, I was face to face with the Greenland shark, a pair of forceps in one hand and a jar of seawater in the other. I saw its eyes, each one a glazed dome over a powder-blue crater on either side of its head, and fixed my gaze on the single inch-long copepod grasping the shark’s corneas, attached by two long appendages called bullae. This tiny crustacean — part of a sprawling family tree with members present in almost every aquatic environment — looked starkly different in shape and features from many of its closest relatives, much less the distant ones. It had decimated the shark’s vision with its scraping teeth, and I could slightly make out tiny cloudy spots on its eye.

At this point, I had flipped through so many images and recorded footage of the massive shark, but I had yet to see more than a single copepod per eye. Since the first day I witnessed a Greenland shark stranded on the shores of Newfoundland, I had been seeking more information about its strange passenger (I’ve cut-and-pasted my field journal entry from that day below for easy reference). I used the forceps to tease out the copepod’s tiny teeth from the shark’s cornea, one by one, and dropped it into the jar. Then, I dashed straight for the industrial-sized freezer.

It was the only place on the ship dark enough to test my hypothesis. When I first caught wind that Ommatokoita elongata might glow in the darkness of the deep, I tracked down every scientist I could find with a relation to Greenland sharks in order to see the copepod for myself. The number was slim — and with so few Greenland shark researchers to begin with, even my preliminary questions about O. elongata, its life cycle, and its role in sharks’ lives remained unanswered. Luckily, though, I managed to find my way onto a research vessel leaving from a port close enough to my fellowship site.

I dragged the freezer door shut behind me. The other researchers were gently tending to the Greenland shark, which they would release after swiftly collecting small skin samples, taking mouth swabs, and measuring its heart rate and vitals to add to their growing datasets. The sharks are slow swimmers, and they tend to lie incredibly still when surfaced — definitely not a “Shark Week” worthy shot.

My singular copepod and I stood in the darkness to the soundtrack of blood pounding in my ears. I kept my eyes trained on the jar in my hands, searching for any sign of soft glowing. If the bioluminescence theories floating around hold true, any light emitted from the copepod’s body may attract unsuspecting prey in the deep ocean, helping its slow-swimming Greenland shark host capture a live meal.

I waited, and I waited. My eyes adjusted to the darkness, and I was able to make out the vague outline of the jar. O. elongata had long been classified a parasite, considering the damage it inflicts on its hosts, but this categorization tickled my instincts after I found out through emailing shark researchers that the sharks relied more on their other senses to hunt in the deep-sea darkness to begin with. The tiny organism physically harms the shark, but is it still parasitism if the copepod doesn’t hurt the larger, powerful animal’s ability to hunt, scavenge, and thrive?

As time ticked on, I felt the freezer’s chill seep through my layers and replace the rush of adrenaline from running in moments earlier. Once in a while I’d give the jar a little shake and bring it closer to my eyes, just to see if agitation helped trigger any bioluminescence. No such luck.

When I didn’t see any glowing after about twenty minutes, I emerged back onto the main deck. The Greenland shark was swimming free once again, unharmed. I felt the brisk, salty air dance across my face as I filtered out my copepod and re-filled the jar with preservative ethanol. A faint sense of dread hung over me — it was looking less and less like the tiny animal glowed, which meant that a mutually beneficial arrangement based around bioluminescence was unlikely. As we prepared to continue to our next site, my mind was searching for ways I could figure out if there were any other interesting dynamics of the shark-copepod relationship.

There are two weeks left of the expedition, and I plan to continue to retrieve copepods clinging to shark eyes, run into the pitch-black freezer, and preserve them in small jars. If I’m not able to figure out more about these supposed-parasites, hopefully these specimens leave a way in for someone new to pick up when I’m not around in the future.

08.01.15

Dear Tara,

Thank you for your email. I authored a couple papers about Greenland sharks and Pacific sleeper sharks several years ago (attached below).

As for the copepod Ommatokoita elongata that attaches to their eyes, I unfortunately am not certain what more I can provide past the information you referred to in your note. Some suspect that they choose the cornea as their landing pad since this area is generally not very well protected by the shark’s immune system. Additionally, it is the only surface of the shark that is not covered in microscopic spines known as dermal denticles, which the O. elongata copepod would have trouble attaching to.

These are well-loved, ancient sharks, so I am not surprised to see speculation and stories surrounding their eye-passengers. I am happy to chat further with you about my research — let me know.

07.27.15

I smelled it before I saw it — a prickly, foul odor that reminded me of the scent of urine wafted over my senses. My eyes tingled, and I blinked until water pooled at their edges. Whatever was in the air displeased my eyes almost as much as it did my nose.

There on the shore, the highest tide barely lapping at its side, lay a mottled grey mass about 11 feet long. The ghost of two triangle-shaped dorsal fins remained in the damp sand further up the waterline, from when it must have rolled with the current in a feeble attempt to slip back into the sea. As I slowly approached, I could make out the silhouette of an agape mouth turned toward the amber sky that was set below a blunt snout. From the pupil of its right eye hung what looked like an extruded skin tag — no way it can see around that, I thought. Just as I was about to move closer to get a better look, two people materialized with a long, sturdy rope. They began looping it around the shark’s tail.

I watched, stunned and wondering if this was allowed, if I should call someone, if I should yell at them myself to stop trying to take it away. Like, isn’t it illegal to mess with big sea animals like this? I caught my words in my mouth, though, when I realized they were coaxing the shark toward the ocean.

Amidst their hurried conversation about shark-moving logistics, I grasped a few words from where I stood 20 feet away: Greenland, scavenge, deep sea. They gently tugged it into the waves, inch by inch. Once the creature’s face was partially submerged with its wide-open mouth no longer visible, water gushed past its gill flaps and it exhaled back to life, though its body remained still. One person let out a small yelp, but the other stood their ground without so much as flinching. I glanced toward the horizon to see the sun beginning to melt back into the sea just as the shark exhaled once more and trickled out of the loosely tied rope, beating its now-freed tail once to push forward.

And just like that, it disappeared.

I was left with the wind drumming against my ears, the cry of hungry seagulls, and the hasty splashing as the two shark-rescuers clambered out of the rising tide. When I had decided to step out for a solo evening stroll by the northeast Newfoundland ocean, I hadn’t anticipated such a run-in.

One of the shark-rescuers, the calm one, noticed me as the two of them finished wading out of the ocean. His smile crinkled across his face, lifting his greying eyebrows. “It’s rare to see those big guys here, I haven’t seen one in years,” he said, and proceeded to tell me that the sharks typically follow the trail of cold water to the ocean’s depths, but occasionally breach the surface if they smell food. “There’s a butcher shop not a mile down the road,” he gestured with one hand, “must’ve been dumping scraps again, the rotting smell would’ve caught their attention.” The two of them wished me well and vanished from the shore as fast as they arrived.

Despite the breeze, the sharp scent still lingered in the air. I walked toward the shallow imprints left behind by the shark, now surrounded by human footprints and stray rope fibers. To this day, I still wonder whether the shark-rescuers were trained biologists or not. I rolled up the cuffs of my jeans and crouched down, sifting through the fine sediment to prevent the rope residue from being washed into the ocean.

Among the strands and grains of sand, I noticed something pale yellow and gelatin-like. It was about an inch long and was caught on one of the rope fibers, hanging on by two thin “arm” structures. I gingerly untangled the appendages from the rope hair and realized I was looking at a tiny organism. I nudged it around with an edge of my fingernail so that its oblong body splayed out on the wet sand.

The long appendages looked almost like they were cut off on one end. This is that skin tag thing I saw on the shark’s eye. Maybe it was yanked off when they pushed the shark out to sea? The realization hit me just as I felt the waves graze the side of my ankles. I quickly dropped my hand into the sand to scoop up my strange finding along with a clump of damp sand before scurrying to higher ground.

The sun had almost slipped fully into the sea. I nudged the creature around in my palm, using the sand as modeling foam to pose it while I took photo after photo. Then, I returned it to the waves.

Additional field notes can be found in the appendix.