The 1,600-mile coast of Mozambique is a magnet for the world's largest marine dwellers, from manta and sting rays to sharks and dolphins. While manta ray numbers are impacted by a migration path that overlaps with their predators, the biggest threat comes from bad fishing practices. Join marine specialists Andrea and Nakia as they set out to identify the favored habitats of manta rays, learn about their migratory habits, and devise strategies to protect the species from catastrophic decline.

To a marine biologist, any attempt at mapping an oceanic food chain begins and ends with plankton, from tiny bacterial algae to soft-bodied animals such as jellyfish. These microscopic miracles are responsible for producing two-thirds of atmospheric oxygen. Their place at the bottom of the chain has the greatest impact on marine life, whether they're providing nourishment for filter-feeders such as sardines and manta rays or predators like dolphins and sharks.