Extras

    Video thumbnail: NOVA DNA-Testing Reef Diversity

    NOVA

    DNA-Testing Reef Diversity

    Marine biologist Laetitia Plaisance investigates species diversity in two coral reefs.

    DNA-Testing Reef Diversity

    Video thumbnail: NOVA Sea Butterflies in Danger

    NOVA

    Sea Butterflies in Danger

    Pteropod populations could decline or vanish due to rising ocean acidity.

    Sea Butterflies in Danger

    Video thumbnail: NOVA Lethal Seas Preview

    NOVA

    Lethal Seas Preview

    A unique coral reef in Papua New Guinea shows what the future may hold as oceans acidify.

    Lethal Seas Preview