NOOA Ocean Explorer / National Exploration and Research
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Exploration of seamount Vailulu'u by a manned submersible vehicle (ROV) revealed a new 300-meter-high volcano around American Samoa that has grown in the summit crater in less than four years.
Several types of hydrothermal vents fill Vailulu'u crater with particles that reduce visibility to less than a few meters in some regions.
Low-temperature hydrothermal vents at the Nafanua summit (at 708 meters depth) host a thriving population of deep-sea green eels (Dysommia rusosa).
Vailulu'u is an underwater volcano located about 20 miles east of Ta'u Island in American Samoa. During an expedition to the volcano in 2005, scientists encountered fissures of a hydrothermal vent at a depth of 708 meters, where thriving aggregations of eels lived.
These eels, identified as Dysommina rugosa, are known from trawl samples in both the Atlantic and Pacific oceans, but have never been studied in their natural habitat.
Although eels thrive in hydrothermal vents at the summit of Nafanua, vents elsewhere in the crater cause mass mortality.
Paradoxically, the same anticyclonic flows that provide food for eels may also concentrate a variety of nektonic animals in a death trap of toxic hydrothermal fluids.
The body of eels is light brown dorsally, paler ventrally, and the dorsal and anal fins have a white margin.
The posterior third of the anal fin base and posterior seventh of the anal fin are black.
About the NOAA photo:
Shoals of small synaphobranchid eels (Dysommina rugosa) live in the crevices on the summit of Nafanua.
Scientists named this site "Eel City."
Several types of hydrothermal vents fill Vailulu'u crater with particles that reduce visibility to less than a few meters in some regions.
Low-temperature hydrothermal vents at the Nafanua summit (at 708 meters depth) host a thriving population of deep-sea green eels (Dysommia rusosa).
Vailulu'u is an underwater volcano located about 20 miles east of Ta'u Island in American Samoa. During an expedition to the volcano in 2005, scientists encountered fissures of a hydrothermal vent at a depth of 708 meters, where thriving aggregations of eels lived.
These eels, identified as Dysommina rugosa, are known from trawl samples in both the Atlantic and Pacific oceans, but have never been studied in their natural habitat.
Although eels thrive in hydrothermal vents at the summit of Nafanua, vents elsewhere in the crater cause mass mortality.
Paradoxically, the same anticyclonic flows that provide food for eels may also concentrate a variety of nektonic animals in a death trap of toxic hydrothermal fluids.
The body of eels is light brown dorsally, paler ventrally, and the dorsal and anal fins have a white margin.
The posterior third of the anal fin base and posterior seventh of the anal fin are black.
About the NOAA photo:
Shoals of small synaphobranchid eels (Dysommina rugosa) live in the crevices on the summit of Nafanua.
Scientists named this site "Eel City."
