It’s back to the drawing board for halibut iTags that will soon tell us more about where the fish travels than ever before.

The internal tags, which were deployed in 30 halibut two years ago, were the first to test Smart Phone geomagnetic advances to track the migrations of fish. The tags record magnetic field strength on three axes and have accelerometers and pitch and roll detectors, explained Tim Loher, a biologist with the International Pacific Halibut Commission.

“Without being able to tell whether or not your tag is horizontal, you can’t really get the axis of the magnetism....