New Zealand's remote Chatham Islands attract roaming predators from all over the South Pacific - but the resident blue cod and brown skuas might just be the most ferocious of all.

In the wettest corner of New Zealand, where alien ocean creatures flourish under a freshwater layer, crested penguins struggle to raise their chicks in the midst of a harsh Fiordland winter.

Every summer, massive congregations of New Zealand sea lions and giant spider crabs descend upon the sub-Antarctic Auckland Islands to carry out their violent breeding rituals.