NSF - Jellyfish Gone Wild Special Report Text-only Jellyfish Gone Wild HOME Enviromental Change and Jellyfish Swarms 1. 1/3 of the total weight of all life in Monterey Bay is from gelatinous animals. Jellyfish Gone Wild — Home 2. 3 minutes after a person is stung by a deadly box jellyfish, s/he may be dead. Introduction 3. 8 years after fast-reproducing comb jellies invaded in the Black Sea, they dominated it. Biology 4. 20 to 40 people are killed annually from box jellyfish stings in the Philippines alone. Ecology 5. 100 foot-long tentacles may dangle from the lion’s mane jelly. Swarms 6. 400 vast Dead Zones in world oceans are too polluted for almost all life except jellyfish. Locations 7. 1,000+ fist-sized comb jellies filled each cubic meter of water in Black Sea jelly blooms. Gallery 8. 45,000 eggs may be released daily by a single jellyfish. Resources 9. 500,000 people are stung by jellyfish in the Chesapeake Bay annually. 10. 500 million refrigerator-sized jellyfish float into the Sea of Japan daily during blooms. NSF - Jellyfish Gone Wild Special Report Text-only Introduction When distributed in reasonable numbers, native jellyfish play important ecological roles. But when jellyfish populations run wild, they may jam hundreds and perhaps even thousands of square miles with their pulsating, gelatinous bodies. Jellyfish Gone Wild — Home In recent years, massive blooms of stinging jellyfish and jellyfish-like creatures have overrun some of the world’s most important fisheries and tourist destinations--even Introduction transforming large swaths of them into veritable jellytoriums. The result: injuries (sometimes serious) to water enthusiasts and even occasional deaths. Biology Jellyfish swarms have also damaged fisheries, fish farms, seabed mining operations, Ecology desalination plants and large ships. And proving that jellyfish can be political animals, knots Swarms of jellyfish have done the work of anti-nuclear activists: they have disabled nuclear power plants by clogging intake pipes. Locations In short, since the 1980s, worldwide jellyfish blooms have caused hundreds of millions--or Gallery perhaps even billions--of dollars in losses. Worldwide reports of massive jellyfish blooms are triggering speculation that jellyfish swarms are increasing because of human activities. Resources But are they? This report--which is guaranteed to make your skin crawl--explains the basics of jellyfish biology and what scientists have thus far discovered about the causes and future of jellyfish blooms. NSF - Jellyfish Gone Wild Special Report Text-only Biology BIOLOGY OF BLOBS WHAT IS A JELLYFISH? Jellyfish Gone Wild — Home To some degree, the definition of a jellyfish depends on who you ask. Beach-goers generally define jellyfish loosely. They use the word “jellyfish” (along with qualifiers such as “ick!”) to Introduction describe just about any transparent, slumped lump stranded in the sand, and any shapeless, ghost-like creature that lurks in the oceanic murk--whether it is giving swimmers Biology painful stings or just creepily brushing against their skin. Anatomy By contrast, scientists define jellyfish narrowly. To be classified as a “true jellyfish” by Reproduction scientists, an animal must have stingers, have a bell-shaped body as an adult, and belong to the group of animals (phylum) known as Cnidaria. In addition, most true jellyfish have Sting tentacles and eat plankton. Note that jellyfish, which are invertebrates and don’t have gills, How They Swim are not fish. Video When scientists categorize animals, they distinguish “true jellyfish” from various types of jellyfish-like animals that look, swarm and squish like jellyfish, but are not jellyfish in the Ecology zoological sense. Swarms For example, jellyfish-like animals known as comb jellies--like true jellyfish--have slimy, transparent bodies and tentacles, and populate the world’s oceans in large numbers. But Locations comb jellies are not classified as “true jellyfish” because they lack stingers and bell-shaped bodies and have different life cycles than true jellyfish. (Comb jellies are classified as Gallery ctenophores). Resources THE MANY FORMS OF GELATINOUS ANIMALS The bodies of some gelatinous animals are smaller than contact lenses; others are bigger than truck wheels. Some have tentacles; some don’t. Although jellyfish are famous for their bell-shaped bodies, gelatinous animals come in many shapes. In fact, the longest animals in the world are jellyfish-like animals known as Siphonophores, which live in the open ocean. Many Siphonophores have long, thin shapes and some reach 130 feet in length, which is about the height of a 13-story building. By comparison, the maximum length of the Blue Whale, the largest mammal on Earth, is about 110 feet. The best known siphonophore is the Portuguese man-of-war, whose giant stinging tentacles may extend dozens of yards. ---------------- Caption/Credit: BEACH BUMMBER 150 million people worldwide are exposed annually to jellyfish. About 200,000 jellyfish stings occur in Florida annually. Credit: Erion Cuko DEATH BY JELLYCIDE The comb jelly known as Beroe eats other species of comb jellies. By doing so, it has helped control population explosions of comb jellies in various worldwide locations. Credit: Casey Dunn NSF - Jellyfish Gone Wild Special Report Text-only Anatomy JELLYFISH ANATOMY: A BELL WITH FEW WHISTLES Jellyfish are the simplest swimming animals on Earth. They are composed of about 95 percent water. (By contrast, humans are about 65 percent water.) The high water content Jellyfish Gone Wild — Home of jellyfish explains why they immediately collapse into defeated, deflated blobs when removed from water. Introduction With few exceptions, jellyfish are brainless, bloodless, boneless and heartless, and have Biology only the most elementary nervous systems. So simple, each jellyfish is but a few evolutionary steps beyond being just a stinging bladder of sea water. In fact, jellyfish are so Anatomy at one with water that they are barely distinguishable from their marine habitats via Reproduction sophisticated, acoustic surveys. Sting What’s more, the transparent, ghost-like bodies of jellyfish provide excellent camouflage, How They Swim enabling jellyfish to hide in plain sight from most prey species, and thereby surprise them. Video The simplicity of jellyfish and their resulting simpatico with the sea helps explain the adaptability of jellyfish, which have survived on Earth for over 500 million years. Moreover, Ecology the ability of these most simple creatures to dominate and essentially rule many diverse ecosystems testifies to the potential power of the lowest common denominator. Swarms Illustration Credit: Zina Deretsky, National Science Foundation Locations Gallery Resources JELLYFISH ANATOMY: A BELL WITH FEW WHISTLES Jellyfish are the simplest swimming animals on Earth. They are composed of about 95 percent water. (By contrast, humans are about 65 percent water.) The high water content of jellyfish explains why they immediately collapse into defeated, deflated blobs when removed from water. With few exceptions, jellyfish are brainless, bloodless, boneless and heartless, and have only the most elementary ner- vous systems. So simple, each jellyfish is but a few evolutionary steps beyond being just a stinging bladder of sea water. In fact, jellyfish are so at one with water that they are barely distinguishable from their marine habitats via sophisticated, acoustic surveys. What’s more, the transparent, ghost-like bodies of jellyfish provide excellent camouflage, enabling jellyfish to hide in plain sight from most prey species, and thereby surprise them. The simplicity of jellyfish and their resulting simpatico with the sea helps explain the adaptability of jellyfish, which have survived on Earth for over 500 million years. Moreover, the ability of these most simple creatures to dominate and essentially rule many diverse ecosystems testifies to the potential power of the lowest common denominator. Credit: Image - Zina Deretsky, National Science Foundation Writing - Lily Whiteman, National Science Foundation National Science Foundation http://www.nsf.gov For more information on Jellyfish see: Where Discoveries Begin… http://nsf.gov/news/special_reports/jellyfish/index.jsp NSF - Jellyfish Gone Wild Special Report Text-only Reproduction THE HOLY GRAIL TO UNDERSTANDING JELLYFISH BLOOMS JELLYFISH REPRODUCTION: Many jellyfish species reproduce extraordinarily quickly. How? By using a peculiar Jellyfish Gone Wild — Home combination of sexual and asexual reproduction involving these steps: Introduction 1. Eggs and sperm are released by adult jellyfish--sometimes at incredible rates. For example, jellyfish known as sea nettles that live in the Chesapeake Bay may each shed Biology 40,000 eggs daily. Anatomy 2. A jellyfish egg unites with a jellyfish sperm to produce a larva. Reproduction 3. Each larva attaches to a hard surface, such as a rock or an artificial structure like a Sting drilling rig, at the ocean bottom. How They Swim 4. The larva lives as a stationary polyp at the ocean bottom. Although much about polyps -- Video which have only rarely been found in the wild--remains mysterious, scientists suspect that they may simultaneously blanket large expanses of ocean floor. They also suspect that Ecology polyps may opportunistically extend their polyp phase from days to even years or decades until conditions, such as temperature and food, are favorable to their survival as adults. Swarms 5. Once conditions become favorable,