Contact mines, magnetic mines, and marine life

What happens if a whale strikes a naval mine?

A contact mine may explode, but a magnetic mine should not because a whale does not produce a ship-sized magnetic disturbance.

Marine life provides an unusual way to distinguish two fundamental firing mechanisms. A contact mine responds when something physically strikes its horns, so a whale could trigger the weapon and be killed. A magnetic mine instead senses a sufficiently large disturbance in the surrounding magnetic field. A whale should not reproduce the signature of a metal ship and therefore should not activate that mechanism. The example makes the practical difference between contact and influence mines easy to remember.