With their hypotheses developed and their study subjects chosen, Dr. Mellish and the team began the detailed process of planning their fieldwork. The team's field season in Antarctica needed to coincide with the seal's reproductive season, which runs from late October to December. It would be important to arrive by early October to maximize their time before the late spring ice melt made it unsafe to work on the sea ice.
The team chose research sites on Erebus Bay, a pupping and breeding area just a short snowmobile ride from the U.S. base at McMurdo Station. From the Erebus Bay location, they'd select forty healthy seals to participate in the study. It was decided that only healthy animals should be studied and that, of the adults studied, all should be females. This would help prevent outside variables from complicating the data.
Navigate through the pictures below to learn about the tools the researchers used to select healthy animals for their project:
The team was able to work directly with each seal to complete its initial health assessment. However, to collect research data from the healthy animals, the researchers would need to monitor the seals as they went about their daily lives. Since a lot of a seal's time is spent beneath the sea ice - where it's difficult for researchers to observe them directly - this data would have to be collected remotely. To do this, the team outfitted each seal with specially engineered instruments, called data loggers, that would record and store the team's data.
VIDEO: STUDYING SEALS USING DATA LOGGERS
Dr. Markus Horning explains how the research team used data loggers to collect data for the Weddell seal project. (2:19)
My name is Markus Horning, and I am an Associate Professor of Wildlife with Oregon State University’s Marine Mammal Institute. I’ve worked with Weddell seals in the Antarctic ever since my first trip to the Antarctic in 1981. My expertise that I bring to the table is related to my ability to bridge engineering and biology. I’m a biologist by training, I have a Ph.D. in biology, but I’ve always dabbled in electronics. We really can accomplish much more in our attempts to study and understand these animals if we use what we call “telemetry devices.” Basically, we use fancy electronics that can go with the animal where they go and where we can’t. Often times where I come in is figuring out, ‘Okay, this is the question, this is the data we need in order to be able to answer this question we have about the biology of this animal.’ Then I ask, ‘How can we get that data?’ and I find specialty sensors that give us exactly that data that we need.
In this project we actually have several separate devices that we glue to the back of an animal. These are multi-channel devices - they have many different sensors. The information that we’re really most interested in is the information we get from the heat flux sensors. We glue these onto the surface of the skin of the seal and they measure exactly how much heat the animal is transferring to the cold water or cold air. To be able to understand this data and the patterns we see in terms of heat dissipation, we also need to record the behavior of the animal. That’s why we’re recording dive depth, swim speed, because that really determines the physiological state of an animal.
If everything works well we find our animal after about five days, I’d say, and everything is still attached. We immobilize the animal a second time and we just peel everything off, or we shave a little bit of fur off. We get everything back home and we download the data. We want to recover the equipment so we can use it again on another animal, but also because the devices that we use actually record the most important information in memory. So, unless we recover the device we don’t have access to the data that we really want.
WHO IS STUDYING SEALS?
HYPOTHESIS (n) - a proposed explanation to a question that must be tested
PUPPING SEASON (n) - the time during the year when seal pups are born
OUTSIDE VARIABLE (n) - something not being tested in a study that could impact the data
DATA (n) - values for something measured
MONITOR (v) - to keep surveillance over something
REMOTELY (adv) - from a distance, without direct contact
DATA LOGGER (n) - a device that measures and stores data on the activity or condition of an animal.
