Jellyfish Gone Wild — Text-only | Flash Special Report
The Ecological Clout of Jellyfish
Even when jellyfish and other gelatinous creatures are not gathering in swarms, they account for large proportions of the life in some marine ecosystems and even dominate some ecosystems.
JELLYFISH ARE IMPORTANT PLAYERS
Evidence of the abundance of jellyfish includes ongoing surveys of Monterey Bay led by Bruce Robison of the Monterey Bay Aquarium Research Institute; these surveys involve using remotely operated cameras to film animals living throughout the water column--from the ocean’s surface to its floor.
Robison says that his studies indicate that “jellyfish and other gelatinous animals currently account for at least one-third of the biomass (total weight of all living creatures) in the water column in Monterey Bay.”
In addition, a recent study led by Cynthia Suchman of the Virginia Institute of Marine Science and the National Science Foundation showed that jellyfish are even more abundant than fish in a fish-rich region off the coast of Cape Blanco, Ore. Because this study confirms the results of similar studies of the area that were conducted in the 1980s, it suggests that the current abundance of jellyfish in this area is not an abnormal or unusual phenomenon.
The longevity, adaptability and global abundance of jellyfish suggests that the saying, “there will always be another fish in the sea” might be more appropriately phrased, “there will always be another jellyfish in the sea.”
DO JELLYFISH GET ENOUGH RESPECT?
Despite the importance of jellyfish to marine ecosystems, these sea creatures have traditionally been underappreciated by the scientific community. In fact, most marine scientists have historically regarded jellyfish as interesting oddities (at best) and usually as only undesirable, unavoidable bycatch that interferes with studies of fish--long considered the true stars of marine ecosystems.
As a result, when marine ecologists pulled up research nets laden with jellyfish, they often simply ignored or discarded their gelatinous hauls. “But the truth is,” says Jack Costello of Providence College, “that researchers were pulling up jellyfish--not because they are unimportant--but because they are important, influential members of marine communities, and always have been.”
In addition to suffering from unwarranted biases, research of jellyfish (many of which have painful stings) has been hampered by a bevy of practical obstacles. For example, jellyfish are extremely fragile and are frequently damaged by nets. Therefore, it is difficult to collect jellyfish. In addition, it is difficult to raise jellyfish in captivity and to preserve their bodies. As a result, we generally know more about fish than jellyfish and much of our understanding of jellyfish is the result of recent research.
Sporting a meter-wide bed and up to seven fleshy arms, “Big Red” was discovered in California’s coastal waters by scientists in 2003. It lives at depths of 2,000 to 4,800 feet off the west coast of North America, Hawaii and Japan.
Credit: © 2002 MBARI
A remotely operated vehicle (ROV) collects gelatinous animals from the depths of Monterey Bay in California. As scientists explore more marine environments, they are discovering new species of gelatinous animals. Credit: © 2005 MBARI