New Deep-Sea Creatures Found in Atlantic
James Owen in London
for National Geographic News
|August 5, 2004|
New deep-sea creatures have surfaced during a two-month voyage of
scientific discovery in the mid-Atlantic Ocean. Researchers arrived back
in Norway yesterday with a catch that includes fish and squid that may
be new to science.
Docking late yesterday, the research vessel G.O. Sars returned to Bergen, Norway, laden with a cargo of strange creatures trawled from the mid-Atlantic abyss. Collected at depths of up to 4 kilometers (2.5 miles), the haul of 80,000 specimens will now be carefully studied.
The research team says it also gathered spectacular images of seabed scavengers and valuable new insights about life along the Mid-Atlantic Ridge (MAR). The MAR, a range of undersea mountains as tall as the European Alps, divides the ocean floor between the Americas to the west and Europe and Africa to the east.
The two-month MAR-ECO expedition formed part of the Census of Marine Life. The census is a billion-dollar venture based in Washington, D.C., that will assess the diversity, distribution, and abundance of the planet's ocean life. Scientists from 16 nations took part in the MAR-ECO research project.
Finds highlighted by the Norwegian-led team include what may be a new species of anglerfish, two previously unknown squid species, and swirling rings of planktonic organisms more than 10 kilometers (6.2 miles) wide. The team also found straight lines of evenly spaced holes in the seabed that appear to have been engineered by animals.
These discoveries were made using the latest undersea technology, such as remotely operated vehicles (ROVs), seabed landers equipped with cameras, and hydroacoustic recorders.
"Each time we splashed into the sea with an ROV we encountered wondrous and apparently undescribed animals that behave in unexpected ways," said MAR-ECO project leader Odd Aksel Bergstad, from the Institute for Marine Research in Bergen, Norway.
ROVs revealed that different types of deepwater jellyfish segregate into layers according to depth, Bergstad said. A spectacular array of bottom dwellers such as sea lilies, brittle stars, sponges, and bivalves congregate on coral reefs at depths of up to 1,340 meters (4,400 feet).
"Observed diversity and density of fauna associated with deep coral banks was remarkable," Bergstad added. "At around 2,000 meters [6,400 feet] we observed a great number of traces left by an unknown animal. The traces were almost straight or curved lines of regularly placed perforations, as if somebody used a sewing machine to create this landscape."
The researchers suspect the burrows were the work of a large, blind lobster, a specimen of which was caught during the team's deep-sea trawls. "But how and why can these lines be that straight?" Bergstad asked.
The voyage's findings raise other nysteries. Two specimens of a peculiar semitransparent blue-pink fish, Aphyonus gelatinosus, were recovered. Coated in a gelatinous layer, it had previously been recorded only once in the North Atlantic.
"Members of this fish family are viviparous, which means that instead of spawning eggs, they give birth to young," Bergstad said. "Practically nothing is known about their biology."
The team also turned up a type of anglerfish never before seen. So-called because they attract prey by waggling a glowing "lure" attached by a "rod" to their heads, anglerfish are the most diverse group of fishes below 1,000 meters (3,280 feet). The new, spiny specimen is thought to belong to the genus Lophodolos. Bergstad said the structure of its head and luring apparatus distinguish it from the two known species in the genus.
The team was not yet able to identify the species of several other anglerfish, Bergstad says. "It would not be surprising if some of these forms proved to be new to science as well after detailed examination," he added.
Of around 50 different types of octopods (the order of mollusks that includes octopuses) and squid captured, two deep-sea squid may also be new species.
The first of the squid, which is deep orange with a small head and unusually small, semi-opaque eyes, is thought to belong to a family with just one named species to date.
The second unknown squid lost its tentacles in the trawl net. Another was later caught that was even more damaged, though its tentacles were still intact. Taken together, the two specimens should provide enough information to establish if this, too, is a new species, Bergstad said.
Bergstad was joined by scientists from 13 countries for the voyage between Iceland and the Azores islands off Portugal. They included researchers from Oceanlab at the U.K.'s University of Aberdeen. This group operated a seabed lander equipped with a digital camera.
The Oceanlab team discovered that the Mid-Atlantic Ridge is a barrier to the movement of deep-sea fish between the east and west Atlantic Ocean. For instance, abyssal grenadier fish were confined to valleys on either side of the ridge. Tests on samples will determine whether eastern and western populations are, in fact, genetically distinct.
The team also filmed wolf fish and deep-sea sharks, which fought over mackerel bait attached to the lander.
But the fearsome wolf fish did exhibit a caring side to its nature, according to Oceanlab director Monty Priede. Males and females paired up in elaborate courtship rituals before keeping guard over their eggs.
"We had no idea these fish would be found living in the mid-ocean like this," he said. "It was quite poignant to see the devoted 'ugly couple' in their deep-sea Eden."
Bergstad emphasized that, not long ago, this type of search would have been imposible: "Investigations of [deep-sea] marine life have just begun, and it is only nowwhen we can utilize custom-built research ships and the finest modern technologythat we can learn how ecosystems in the oceans are structured and function."
Until now the deep sea had been largely, and almost literally, an unfathomable world.
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