S1, E2: Sharks are the life force of our oceans. They must reproduce to maintain a balanced, marine ecosystem. Little is known about where sharks go to mate and pup, so the two research teams are keen to learn more. The northern research team heads to K'gari, Queensland, located 80 kilometres south of the world-famous Great Barrier Reef. The team wants to locate mating and birthing spots to protect these areas for the sustainability of large shark populations. Dr. Bonnie Holmes and Dr. Johan Gustafson run five fishing rods along one kilometre of sand, in the hopes of catching the most elusive shark of all: a pregnant female. If they can find and tag her with satellite technology, she could lead them to her pupping grounds. Catching and tagging sharks from the shallows is a difficult assignment, so they must work carefully and quickly to succeed.