The Search for Krill
July 3, 2000

	Krill Net Photograph by Kip Evans

It’s 48 minutes after midnight or as they say at sea, 00:48. Hot chocolate in July seems improbable but it’s now welcome in combination with cold water spilling onto the deck, fanned by a steady cool breeze. Dr. Baldo Marinovic, specialist in the biology of krill, Jennifer Makowka, Marine Sanctuary intern and a member of McArthur’s crew, Scott Gage, and I are the only ones left on the ship’s fantail. An hour ago, more than a dozen people gathered around the first net haul, helping to land the catch—thousands of inch-long creatures that, when concentrated at the end of a fine-mesh net barely filled a quart jar. Each translucent pink creature sparkles with an eerie blue glow, the living light of bioluminescence, the mass appearing like a double handful of stars. Fewer people stayed on deck to witness the second haul, and now only the four of us are here to lower the three-net array, pay out the cable, wait for the tow, and then watch the net rise out of the water, alive with jellies, crustaceans, lanternfish and other captive organisms. It has been a long day, starting before dawn for some. Jennifer Makowka who intends not to miss a minute of any action, has been on hand for every aspect of the sub operations—and now, too, is present for the extraction of each and every krill from Baldo’s plankton nets. By the time we finish tonight, it will be just a few hours before the sub crew is up to take advantage of calm seas that typically start the day. With luck, Kip Evans will be in the sub and over the side by 7:00 AM. His goal? To see and document the aggregations of krill that Baldo has just sampled with nets.

	Retrieving Krill Nets Photograph by Kip Evans

Among other things net-caught samples and acoustic images cannot reveal are questions about what creatures other than blue whales may be dining on krill, as well as basic knowledge of the behavior of the krill when they are undisturbed. How densely packed are they? Do they interact with one another or just mill about? Do they sort themselves out according to size or stay in mixed age groups? Just as the direct observations made from the sub in the Channel Islands have helped interpret geological data obtained acoustically, so will direct observations of krill behavior help understand the results of sonar images and net tows through swarms of the little beasts.

	Dr. Baldo Marinovic Photograph by Kip Evans

Rather than calming down, the seas built more strongly through the night, with white caps now at 0900 topping choppy waves coupled with rising swells. Deploying the sub is out of the question, but after brief “what-to-do” conference, we decide to try using the National Geographic’s remotely operated vehicle or ROV. It looks like a large white sled with afterburners—actually twin propellers called thrusters at the back end, and two more positioned in the middle that are used to move the ROV up, down and even to crab sideways. Power comes from the ship through a bright yellow inch and a half thick 2000 ft. [609 m.] cable to an attachment on the back of the vehicle. On the surface, a pilot controls the actions of the ROV while looking at a television monitor that shows in real time what is seen through the lens of the camera mounted on the vehicle’s front end, together with lights. Without a doubt, the trickiest part of operating such a system has to do with managing yards and yards of cranky, twisty, heavy cable. It is usually easier to manage such a system if the support ship is at anchor or can be dynamically positioned over a targeted area, but today we’ll be “live boating,” moving along with the ROV as it explores an area ahead of the McArthur.

	Krill Photograph by Kip Evans

It requires intense concentration on the part of all, from LCDR Michele Bullock on the bridge of the ship to John Vance at the controls of the ROV to the several cable-handlers on the deck who have the job of pulling in or paying out cable as needed. The most demanding role is that of Phil Otalora, Nuytco’s dive supervisor. He is now at the bow, directing the operation using a radio along with gestures and nods to the cable handlers.

At the controls, krill man Baldo Marinovic stares at the screen and pronounces the masses of bright creatures on the screen, “not krill”—but there are lots and lots of whatever they are. Thousands of small crustaceans stream past the camera’s lens, too swiftly to determine more than their shrimp-like nature. “Maybe they’re amphipods,” Baldo says. Suddenly a line appears on the screen. “Is that the ROV’s cable?” someone asks. “No, look—it is a huge siphonophore!” Several yards of firm, translucent jelly streams past, loops over the top of the ROV and disappears into the green-blue haze, 300 feet [91 meters] below the surface.

	John Bance Readies ROV Photograph by Kip Evans

For nearly two hours we search with the ROV in vain for the krill we know are down there, but heavy current overpowers the machine’s ability to stay on course. Reluctantly, we pack it in and hope for calmer seas. Even the sea birds appear to be taking the afternoon off. Following behind the McArthur and sometimes swooping low alongside are more than two dozen blackfooted albatrosses. I count 13, then 26 and finally as many as 32 bobbing astern among the froth-crested waves like elegant ducks. Petrels are there, too, and a few gulls, but I am most entranced by the albatrosses. These great, graceful birds spend most of their lives at sea feeding on squid and small fish, returning to land, usually on remote oceanic islands, only for courtship and nesting.

A sumptuous dinner has been prepared for the evening—roast turkey, mashed potatoes, peas, stuffing, gravy, salad, as well as a vegetarian pasta dish and fresh strawberry shortcake. No one has ever left the McArthur weighing less than when they arrived, even when the seas are rolling as they are now.

	Deploying the ROV Photograph by Kip Evans

Through the night, we pitch, rock and roll, and wonder where to go to find a place calm enough to launch our little submersibles. There is no real lee along this part of the California coast, no islands between here and Hawaii to break the long sweep of ocean swells. After dark, Baldo begins deploying his nets, this time to very gently extract a few that he plans to take back alive to his shore-based lab for studies on their physiology. Again, the nets arise from the sea shimmering with light, mostly from thousands of small gelatinous salps. “You never know about the ocean,” Baldo comments, sloshing buckets of krill across a slippery deck. “The weather prediction is for stronger winds, but tomorrow morning it could be flat calm.”

—Sylvia A. Earle
Project Director
Sustainable Seas Expeditions

[Note: nationalgeographic.com does not research or copyedit dispatches.]