One of the bioengineers interested in biogenic ocean mixing is National Geographic Emerging Explorer Kakani Katija. “I would say my original interests were on animal swimming or jellyfish propulsion,” she says. “In that investigation, some of this work . . . suggested that swimming animals can impart a lot of [ocean] mixing.” Jellies thrive in every ocean, including the tropical Pacific of the Philippines, above.

Photograph by Christopher Diaz, MyShot
  • White-spotted jellies are native to the warm, tropical waters of the western Pacific Ocean, from Oceania through East Asia. The jellies in this photograph were swimming near the Philippines.

    White-spotted jellies have very mild venom and do not pose a threat to human beings. In fact, these jellies do not generally use their venom to capture food at all. Instead, white-spotted jellies are filter feeders, like oysters or sponges. They can filter more than 50 cubic meters (1,766 cubic feet) of seawater every day!

    Microscopic zooplankton are the main food source for white-spotted jellies. Plankton are a key part of the entire marine food web. Because white-spotted jellies often travel in large groups called swarms or smacks, they can disrupt the entire ecosystem of an area by consuming almost all the plankton. Fish, crustaceans, and marine mammals may not be able to find sufficient food in an area with swarms of white-spotted jellies.

    This is especially true where white-spotted jellies are an invasive species. These areas are not home to the marine snails that prey on the jellies in their native habitat. Swarms of white-spotted jellies have impacted ecosystems in the Gulf of California, Gulf of Mexico, and Caribbean Sea.

  • Term Part of Speech Definition Encyclopedic Entry
    ecosystem Noun

    community and interactions of living and nonliving things in an area.

    Encyclopedic Entry: ecosystem
    filter Verb

    to remove particles from a substance by passing the substance through a screen or other material that catches larger particles and lets the rest of the substance pass through.

    filter feeder Noun

    aquatic animal that strains nutrients from water.

    food Noun

    material, usually of plant or animal origin, that living organisms use to obtain nutrients.

    Encyclopedic Entry: food
    food web Noun

    all related food chains in an ecosystem. Also called a food cycle.

    Encyclopedic Entry: food web
    habitat Noun

    environment where an organism lives throughout the year or for shorter periods of time.

    Encyclopedic Entry: habitat
    invasive species Noun

    type of plant or animal that is not indigenous to a particular area and causes economic or environmental harm.

    Encyclopedic Entry: invasive species
    jellyfish Noun

    type of marine animal, not a fish, with a soft body and stinging tentacles.

    microscopic Adjective

    very small.

    tropical Adjective

    existing in the tropics, the latitudes between the Tropic of Cancer in the north and the Tropic of Capricorn in the south.

    venom Noun

    poison fluid made in the bodies of some organisms and secreted for hunting or protection.

    zooplankton Plural Noun

    microscopic, heterotrophic organism that lives in the ocean.