A View to a Krill:
Antarctic Expedition by College of Staten Island Scientists

By Kenneth T. Bach and Terry Mares, College of Staten Island

Top row left to right: Cristina Rhodes, Frank Brooks, Richard Heil, Jarrod Santora, Jenny Gramza, Carol Demartinis. Bottom row left to right: Andre Bernick, Margaret Riggi, Richard Veit, Bala Sundaram.

This last December, an intrepid band of College of Staten Island research-ers headed south for the summer. Yes, the summer. These scientists and their graduate and undergraduate CUNY students were headed far, far south—all the way to Antarctica, where the summer sun is a pretty steady customer. Their mission: to study small, shrimp-like crustaceans known as krill and the birds that feast on them.

Unfamiliar to most Americans, krill are one of the most important planktonic (floating or weakly swimming) crustaceans in the Southern Oceans. They feed upon phytoplankton (planktonic plant life) and, since krill are high in protein, are an important food source for almost all larger organisms in Antarctica, such as mussels, fish, seals, baleen whales, penguins, and other birds.

Although Antarctic krill are small, they are also abundant. And they just might be a valuable potential source of protein for human and live-stock consumption. How would wide-scale commercial krill harvesting affect the delicate and protected Antarctic ecosystem? That is what the research team from CSI is hoping to predict, with the aid of advanced computer modeling.

The team from CSI was headed by biology professor Richard Veit, who was awarded an NSF CAREER Grant for the project. Veit, a bird ecologist and biostatistician, also served as primary researcher. He knows the territory: this was his eleventh trip to the frozen continent. He was joined by mathematics and physics professor Bala Sundaram and seven CSI students. Richard Heil, an ornithologist from the U.S. Fish and Wildlife Service accompanied them as they collected data in an attempt to predict how large-scale krill harvesting might affect indigenous sea-bird populations of cape petrels and albatross.

Top Photo: This rusty trolley, which took 8 people to operate, was a means of island-hopping. Bottom Photo: NSF Research Vessel Gould, with Adelie penguins

They spent a month near Elephant Island, off the tip of the Antarctic Peninsula, not only observing large gatherings of krill, but also recording in detail the feeding behavior of birds in the same vicinity.

The expedition was funded through a grant from the National Science Foundation Office of Polar Programs, which required the trip to combine research and teaching. This provided the perfect opportunity for Veit to engage CSI students in the project. They were required to enroll in a series of courses to help them fully understand the procedures, problems and protocols that such a research project would demand.

At Punta Arenas, Chile, the researchers boarded the NSF research vessel Laurence M. Gould and headed for Antarctica. Summer there translates as temperatures that hover near 30 Fahrenheit, winds that can gust up to 75 mph, and 40-foot-plus ocean swells vaulting over the ship's deck. The Gould needed to deliver supplies to resident research scientists at Palmer Station before sailing on to Elephant Island and commencing around-the-clock data collection.

The researchers towed an echo-sounder behind the ship, which was their window to the underwater world of Antarctica. This echo-sounder, which works similarly to equipment used by deep-sea fishermen, was used to locate and study large gatherings of krill, called swarms, which tend to ride along on the easterly-flowing current through Drake Passage, which separates South America and Antarctica.

Top Photo: Anchoring the Laurence M. Gould at the Palmer research station. Bottom Photo: The Laurence M. Gould docked at Palmer Station. Cristina Rhodes in foreground.

As the Gould navigated northward along six different 25-mile, north-south paths called transects, details of the krill swarms were recorded, including their location, density and depth. Southward bound, they recorded data on the water's conductivity and temperature at varying depths. The ship's location was recorded via a Global Positioning System (GPS) every 12 seconds.

One swarm they encountered was approximately 6 miles long and 80 meters thick. Krill swarms could involve thousand of tons of krill and have a density as high as 10,000 organisms per cubic meter. Why the krill congregate in swarms is unknown; speculation about this has focused on temperature, ocean salinity, nutrient deposits, and the behavior of ocean currents.

As they tracked the location of krill, the researchers also recorded the species and number of birds along the transect lines and details of their behavior. They recorded data on the birds 24 hours a day (twilight lasts only from 12:30 to 3:00 a.m. at this time of year). Working in 12-hour shifts, the students stood on the ocean-tossed deck of the ship in wind-chills that often dipped below zero degrees Fahrenheit.

Of Cheerful Neoprene, Tiny Rainbows, Deception Island, & Chatty Penguins From the journal of CSI student Cristina Rhodes: Suits are supposed to save our lives if the ship sinks—thick neoprene of a pretty intense orange that makes you cheerful. But it is a sobering thought to consider being in the engulfing infinity of the ocean in a little neoprene suit. —December 3 The waves breaking against the ship keep forming nice little rainbows, hinting at a note of happiness in spite of the loud threatening hum of the wind and waves causing tremors in the hull of the ship. —December 17 We are heading towards Deception Island. . .At first sight it looks like a circle of mountains with no access, but as you get closer you see a narrow passage into the heart of the island (hence the name). . .There were Chinstrap and Gentoo penguins, quite inquisitive! The island was used in the last century for whaling. . .Large whale vertebras were here and there, as well as ribs, all bleached. —December 21 There were so many penguins [at Bonaparte Point, near Palmer Station] all around us that it didn't seem real. Their happy chatter was noisy yet pleasant. An elephant seal was basking in the sun. —December 23

To create a valid database, each bird had to be continuously observed for a minimum of two minutes. The observers tracked the birds, which could fly at nearly 40 miles per hour, while team members recorded their behavioral data (where they fly, turning patterns, water dives, sitting on the water surface, etc.) This information was entered into laptop computers and personal digital assistants (PDA's), building a thorough database to more accurately generate a bird distribution and behavior map.

Veit says that a final goal of this project is to construct mathematical models to determine how birds may behave depending on the presence or absence of krill in a given location. Another goal is eventually to discover how the birds locate krill swarms (for example, visual or olfactory cues or the behavior of other birds or mammals) and how the birds behave when they detect the prey, as well as how much krill needs to be present and how close to the ocean surface the crustaceans need to be for the birds to become interested.

Since a substantial portion of the computer modeling involves mahematics, Sundaram, who, like Veit, arrived on the CSI campus in 1996, was asked to join the expedition. His first-hand accounting of how the data is collected and what kind of data is available helped shape the acquisition models to facilitate data correlation and improve the accuracy of the projection model.

Sundaram also put together a computer presentation of the research work in Antarctica for his daughter's grade school class. "Children love penguins,” Sundaram commented, "so I included some photos and facts for them. But more than just the penguins, the presentation opened up the world of science and mathematics and its possibilities to them, awaking their imagination. I hope they will carry with them the understanding of how penguins, birds, krill and the entire Antarctic ecosystem are so closely intertwined with mathematics.”

Word of the excitement their presentation created soon spread, and Veit and Sundaram were invited to visit other classrooms. Their dynamic and engaging presentations, replete with living examples of Antarctic krill and inflatable penguin images, have served to instill a sense of the long-lasting and profound effects of interdisciplinary scientific study.

Back in his CSI office, Sundaram, assisted by Ph.D. student Jarrod Santora, face the monumental task of correlating the 20 gigabytes of data they collected at sea. Each database—krill population, bird population and behavior, and water conditions—has been compiled using dedicated software packages.

These individual databases have been cleaned up and are currently being compiled and synchronized to the same 12 second intervals recorded by the GPS system. "Jarrod is really earning his Ph.D. with this one,” Veit says, œand once the data is synchronized we can move onto analyzing it.”

What do they hope to accomplish by running this data in a real-time model?
To find an algorithm, or set of rules, to describe how the birds behave in the presence of large swarms of krill. "We want to build a model,” Sundaram explains, "that would have these birds flying around on a computer...looking for krill.”

If krill eventually become a target of commercial fishermen, whether to provide krill as a delicacy or as chicken feed, scientists will have a computer model to estimate the impact that mass harvests of krill might have on the Antarctic ecosystem.

Mathematically Modeling the Antarctic Ecosystem Professors Richard Veit and Bala Sundaram describe the science of their project. Over the past few years, we have applied recent mathematical developments to the description of spatio-temporal dynamics to modeling the foraging habits of birds. One goal of this research is to learn how seabirds respond to changes in the abundance and distribution of their principle prey, Antarctic krill, Euphausia superba. Krill abundance distribution is affected by physical oceanographic processes such as shear fronts and current boundaries. Thus, models of krill and its predators involve the interplay of Eulerian and Lagrangian dynamics. One novel approach we have been exploring is "agent-based” modeling, in which seabird and krill dynamics are considered independently and œlocal” rules of engagement constructed for their interplay. The rules themselves can be derived from observational data, for example, by contrasting bird behavior in the vicinity of krill swarms to that in areas lacking krill. In turn, the foraging models will make predictions about the dispersion of birds under differing levels of krill abundance. Our long-term goal is to forecast the impact on seabirds of changes in krill stocks. Changes in krill stocks now seem inevitable, due both to changes in climate and future commercial harvesting. For several consecutive Decembers, groups of undergraduate and graduate students will help to survey the insular shelf north of Elephant Island, recording the abundance, distribution and behavior of seabirds. Krill abundance is recorded using echo-sounders and corroborated by net hauls and visual sampling. Physical oceanographic characteristics are recorded at the same time. Assessing the correlation between these voluminous sets of spatio-temporal data takes considerable effort, and we expect the job will take about four months. The primary objective will be to quantify the linkage between prey abundance and bird behavior. Our teaching goals are, first, to introduce urban college students to a spectacular and economically important ecosystem. Through their work on an oceanographic research vessel, students will be exposed to a diverse research topics and methodologies, ranging from behavioral ecology to physical oceanography. On this recent trip, for example, a number of our students assisted a research group from the Woods Hole Oceanographic Institute with their experiments on plankton larvae. Second, back at their campus, students will participate in our development of the models for analyzing and describing the data. This is facilitated by the requirement that all students selected for the trips are required to take courses in mathematical and statistical modeling prior to being selected. Our December expedition culminates several years of collaboration in research and teaching, notably team-taught courses in Mathematical Biology at the undergraduate and graduate level. One such course will be offered in the Biology Program at the Graduate Center this fall. For more information about these courses, contact us at veit@postbox.csi.cuny.edu (for Veit) or bas@math.csi.cuny.edu (for Sundaram).

At present, only a small amount of krill harvesting—approximately 400,000 tons per year—is taking place because it is an expensive proposition. Norwegians consume krill in the form of a high protein paste and the Japanese enjoy them cooked and peeled, much like shrimp.

Currently, there is no supply route or transportation infrastructure in place to move harvested krill to destinations worldwide. Veit recalls that the Soviets used to send factory trawlers, idle during the harsh Russian winters, to harvest krill. Although it was a large-scale operation with 10 to 12 factory-sized trawlers, the Soviets never made a profit. Once the former Soviet Union collapsed in the early 1990s, the new Russian government abandoned the harvests for economic reasons. However, once the logistical problems have been sorted out regarding the mass harvesting of krill, commercial fishermen may turn to krill as a new protein source in feeding human and livestock populations. The data collected and the models developed by the researchers at CSI may aid in the formulation of international policy as we feed our world and protect the delicately balanced Antarctic ecosystem.

As for Veit, he plans to head back to Antarctica again at the end of this year to conduct further research. His current NSF grant, which provides $85,000 per year for four years, ends in 2004. College of Staten Island students with a taste for adventure and who don't mind the heavily layered look will once again be able to join him.

Together, they will help to decide whether the future of planet earth just might include krill-burgers.