Crittercam: More Than an Animal's-Eye View
for National Geographic News
|January 16, 2004|
Since its first test run in 1987, Crittercam steadily has transformed
the way scientists study their marine subjects. The units, designed and
deployed by Greg Marshall and his Remote Imaging team, have traveled
with some of the ocean's most notable residents, from whales and sharks
to turtles, seals, penguins, and even sturgeon.
Best known for providing an "animal's eye" point of view, Crittercam, however, is more than just a video camera. It is technically a data logger, correlating visual and audio information with standard measurements such as depth, pressure, temperature, and time.
"That's why we can work with scientists," explained Mehdi Bakhtiari, Remote Imaging's lead engineer. "If it was only video, then they [scientists] are not that interestedthe video alone doesn't say that much about most animals. You want the video to correlate with something else, some kind of information."
In other words, by adding an AV component to these measurements, Crittercam data helps provide answers to many "why" questions scientists have about their subjects' behaviors. Each system is capable of being customized to record other data according to a particular scientist's needs.
Crittercam's physical design has changed greatly since the first prototype, with the smallest ones now spanning three inches in diameter and weighing approximately one kilogram. Each unit is designed to be proportional to the animal's size and shape, as well as to withstand its native environment. Typical units add only one percent of the animal's own body weight back, and are designed to be as hydrodynamic as possible to reduce "drag" created by the system.
The design process is no simple matter. A case in point: while a tear-shaped housing has been found to produce the least drag, it also reduces available room inside the unit for recording devices. So designing each unit becomes a balancing act, with the animal's comfort and safety being the number one concern.
There are various methods to attach a camera to a subject, including suction cups, fin clamps, and adhesive mounts. Each is designed to release the camera after a given amount of time. Once the unit detaches itself, it can be located for recovery using ultrasound, VHF, or satellite. However, when using VHF or satellite tracking, the camera's antenna must be far enough out of the water and steady enough to send a signal in rough seas. To assist in this effort, the system is engineered to be slightly positively buoyant and to float antenna-end up.
When the unit is located, it then has to be recovered. And that's when the real fun begins. Bakhtiari recently had to travel 90 miles and seven hours by helicopter to recover one particular Crittercam. And that was after two weeks aboard a boat that broke down in choppy Arctic waters, with strong currents pulling the camera just out of reach and five resident polar bears looking on from the nearest ice floe.
So unlike researchers using satellite tags that are deployed but not recovered, Bakhtiari can't relax until the unit is safely back in hand. "While everybody's celebrating, I just have to sit back and wait for the camera to release itself and for me to go and recover it. After recovering [the camera] is the moment that I celebrate, usually."
Remote Imaging's supervising producer Birgit Buhleier couldn't agree more. "It's a $10,000 systemI put it on this wild animal; the animal swims off...I will not know whether it has worked until I get it actually back."
Future enhancements to Crittercam should decrease some risks by providing an even more stable information gathering system. Moving from videotape to solid state media (similar to a computer flash memory card) would increase durability by reducing the amount of mechanical parts that could break or malfunction, as well as greatly increasing the amount of data that could be collected in a single deployment. There are also plans to integrate standard sensors for acceleration, light levels, and salinity as well. And the quest for an ever-smaller unit has Remote Imaging engineers aiming for a two-inch diameter model.
With these and other developments in the works, Crittercam appears ready to roam wherever ocean denizens do.
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