| The Magazine of the CALIFORNIA ACADEMY OF SCIENCES |
| |
|
|
|
Horizons Lights, Camera, Squid
It was like a scene straight out of 20,000 Leagues Under the Sea. A humongous squid displaying the posture of a daddy longlegs and wide, batlike wings hung motionless in the water just outside the submersible Nautile. The astonished scientists inside made no attempt to capture the strange-looking animal. At 4,735 meters deep off the coast of Brazil, they had other pressing research to attend to. But to ensure that colleagues wouldn’t accuse them of telling fish tales, they made sure to record it with the submersible’s video camera. Since that first encounter back in 1988, researchers have captured the 7-meter-long squid on camera eight times in deep waters around the world. But not once has someone laid hands on one, dead or alive. That hasn’t stopped marine biologist Michael Vecchione with the National Oceanic and Atmospheric Administration and colleagues from publishing a paper describing the “mystery squid” in the December 14 issue of the journal Science. “It’s a really bizarre animal,” says Vecchione, who is based at the National Museum of Natural History in Washington, D.C. “Clearly, they don’t fit into any known family of cephalopods.” Identifying an animal sans sample in hand is hardly the usual scientific route. It’s like trumpeting the existence of the Yeti on the strength of a few blurry snapshots. Yet as humans push further into Earth’s most inaccessible environments, collecting examples of the local flora and fauna on film rather than in traditional jars of formaldehyde is becoming increasingly common. And biologists are embracing the value of video as an indispensable tool for studying animals in their natural habitat. “There is a revolution taking place. Although the squid’s description is based on appearances on video camera, we nevertheless know much more about the animal than if we had caught one, because most animals designed to work in midwater are extremely fragile. So if you catch one in a net, it turns into two handfuls of mush,” says Bruce Robison, a deep sea biologist at the Monterey Bay Aquarium Research Institute in Moss Landing, California. The squid films show the animal floating just above the ocean floor, holding what appear to be ten identical suckered arms straight out like the ribs of an umbrella. All other known squid have eight suckered arms with two modified tentacles. The squid’s arms bend at an “elbow” near the body, then narrow into many meters of exceptionally limp, noodle-like tentacles that appear sucker-free. The bends in its boneless arms might have disappeared if the animal been caught in a net and entombed in a bottle. One squid that happened to touch the submersible with its arms had a hard time disentangling itself. As it flapped its fins to get away, it stretched its tentacles taut as rubber bands until they snapped free. The lower arms, Vecchione says, “seem to be really sticky. I think it drifts in the water, and the really long spaghetti-like extensions hanging from the elbows dangle down and wait for prey to bump into them.” Passively trolling for food with the web of its arms is unheard of among squid, which typically snatch swimming prey with a quick flick of a muscular tentacle. From the video, Vecchione suspects the squid may be adults of the family Magnapinnidae, known only from juveniles Vecchione found in the stomach of another fish. Although less than five centimeters long, one had unusually wide fins and sprouted wormlike extensions from its arms. Finding such a large and apparently common animal so recently demonstrates how little we know about the life in the deep seas. Despite its distinctiveness, the mystery squid will remain officially nameless until its limp body is scooped from the deep. It’s in good company. The Indonesian mimic octopus, famed for impersonating the shape of venomous animals to escape predators, also maintains only a pixillated presence in scientific collections. “Therefore it’s octopus species X because no one has a real specimen to accession into any of the museums,” says Roger Hanlon, an animal behavior researcher at the Marine Biological Laboratory in Woods Hole, Massachusetts. The International Code of Nomenclature, which governs the description and definition of species, still requires a physical type specimen to be examined and stored before the creature can be recognized. No plans are in the works to permit virtual animals anytime soon. “Without a specimen, one can never be sure of the identify of the creature. For that reason, video will not replace the importance of actual specimens,” says John McCosker, Senior Scientist at the California Academy of Sciences. But the fact that Vecchione and others have been able to pin down so much information about animals glimpsed so many leagues under the sea suggests that many scientists will be focusing on film in the future. The Nitrogen Solution: No Rust, No Aliens Hide away on a ship, ride the high seas, then go on to live the good life in a faraway paradise. This romantic notion once started many a young man on a life of adventure far from home. Today, it’s what billions of creatures do every year as they crisscross the oceans in the ballast water of ships. When these tiny stowaways disembark in foreign harbors, many find a predator-free frontier ripe for the conquering. Centuries of oceanic commerce have seeded global waters with thousands of exotic species. To ride higher within shallow harbors, cargo ships unload thousands of gallons of stabilizing ballast water teeming with millions of tiny sea creatures. Today, these animals and their progeny have radically altered aquatic ecosystems from Australia to the St. Lawrence Seaway. They have transformed the structure of habitats, spread diseases such as cholera worldwide, and may be responsible for more than 70 percent of the native marine species extinctions that have occurred in the twentieth century. A 1999 report by Cornell University ecologist David Pimentel and colleagues estimated the annual cost of controlling zebra mussels in the United States at $3 billion. But with no laws demanding sterile ballast dumps, shipowners have dismissed filters and poisons as too expensive. Now a method to prevent rust formation in ships promises to leave many marine invaders dead in the water. Marine ecologist Mario Tamburri of the Monterey Bay Aquarium Research Institute and Kerstin Wasson, research coordinator for the Elkhorn Slough National Estuarine Research Reserve, have found that purging oxygen from ballast water cuts ship corrosion and kills aquatic animals to boot. Originally developed by engineers at Sumitomo Heavy Industries in Japan, the technique purifies nitrogen from air and constantly bubbles it into ballast water tanks. Shipboard tests have proved the system capable of keeping ballast water oxygen levels near zero for months at a time, cutting rust by 90 percent. Best of all, it’s far less expensive than keeping tanks coated with anticorrosion paint. Over the 25-year lifetime of the average commercial ship, savings could total as much as $1.75 million. In their study, the scientists tested how juvenile forms of three notorious invasive species-the Australian tube worm (Ficopomatus enigmaticus), the zebra mussel (Dreissena polymorpha), and the European green shore crab (Carcinus maenas)—would react to low oxygen levels. Smaller species and juveniles of invertebrates, fish, and algae are the most common types of stowaways because they are small enough pass through the coarse filters on ballast tank pumps. The researchers then bubbled nitrogen into the animals’ airtight tanks. Tamburri and Wasson report in the journal Biological Conservation that at the end of two days, 79 percent of the tube worms, 82 percent of the zebra mussels, and 97 percent of the crabs had died. They estimate that by the end of a long ocean voyage, virtually 100 percent of these animals would be dead. Survivors would be limited to plant spores and seeds, viruses and anaerobic bacteria capable of withstanding long periods without oxygen. Wasson’s research has identified over 55 species of invasive invertebrates in tiny Elkhorn Slough just north of Monterey. But the problem looms much larger in busy shipping ports. Scientists have found 234 known alien species in San Francisco Bay and its Delta; 119 in the Hudson River Basin, and 99 in Port Phillip Bay in southern Australia. The Smithsonian and Environmental Research Center in Chesapeake Bay estimates that ships empty 3 million metric tons of ballast water into Los Angeles Harbor every year, unloading perhaps 300 million miniature immigrants at a time. Even if just one organism in a million gains a foothold and survives, the impact on the local ecosystem is staggering. “You can’t undo past damage, but you can prevent future invasions from occurring.” Wasson says. California Academy of Sciences marine biologist Terry Gosliner says that while the system sounds effective at controlling many potential invasives, “the organisms that survive the treatment will probably be some of the most resilient in a new environment. My concern would be that you are selecting the fiercest competitors, the ones that are hardest to eliminate.” He would prefer ships to exchange their ballast water in mid-ocean, where the organisms taken on will be unsuited to survive after being deposited in a harbor. But until international law mandates either mid-ocean exchanges or the sterilization of ballast water, deoxygenation will help weed out many of the oceans’ hitchhikers. Kathleen Wong is Senior Editor of California Wild. |
