In Hawaii the weather conditions are usually quite mild for deploying and testing the equipment. However, it is not unusual to have high winds and tropical storms for several days in a row, making field activity impractical or impossible. The whales are extremely active vocally during their winters in Hawaii when they are mating and birthing calves, so when the system is up and functioning the songs can be heard for hours at a time over a period of several months.
In Alaska, in addition to the whales being less vocal, the environmental challenges are unique and require patience and perseverance. These challenges include tidal surges, extreme water temperature, remoteness of location, and inconsistent solar power. One buoy was deployed in Alaska during the summer of 2004, and up to four were deployed there during the summer of 2005, with intermittent success at transmission.
As with any serious scientific or technical project, the problems you face aren't always those you expect, and the solutions you anticipate do not always work.
A few of the problems we have encountered (and solved) so far:
- Our very first CetaBuoy (which was shaped like a box rather than our current cylinder shape) didn't float well with all of the equipment it had, and had to be re-engineered.
- The commercial glue we initially used for underwater applications changed its formula at some point, and suddenly we could no longer depend on it holding out in the water. We had to find a different glue which was equally effective.
- The hydrophone is attached to the rigging which connects the anchor and the CetaBuoy. It is an extremely sensitive microphone, and was picking up far more noise from contact with the rigging than it was whale sounds. We engineered a "standoff" to keep the hydrophone sufficiently separated from the rigging that it wouldn't pick up extraneous noise.
- One of our pre-packaged electronics components was designed such that it would only function properly in a relatively temperate environment. Hence it worked perfectly during the testing in our California laboratory, but failed immediately even in the summer weather of Alaska. The solution was a simple (hair-thin) wire to ground a voltage regulator component, but until we discovered the solution we could not move forward with our mission.
- Finding the right spot to drop an anchor which will remain for several months at a time was a greater challenge than we expected, because of the constantly changing contour of the ocean floor, severe drops off of continental shelves, and the need to avoid sensitive areas such as coral reefs.