Vailulu'u Seamount, Samoa: Life and death on an active submarine volcano.
Submersible exploration of the Samoan hotspot revealed a new, 300-m-tall, volcanic cone, named Nafanua, in the summit crater of Vailulu'u seamount. Nafanua grew from the 1,000-m-deep crater floor in <4 years and could reach the sea surface within decades. Vents fill Vailulu'u crater with a thick suspension of particulates and apparently toxic fluids that mix with seawater entering from the crater breaches. Low-temperature vents form Fe oxide chimneys in many locations and up to 1-m-thick layers of hydrothermal Fe floc on Nafanua. High-temperature (81 degrees C) hydrothermal vents in the northern moat (945-m water depth) produce acidic fluids (pH 2.7) with rising droplets of (probably) liquid CO(2). The Nafanua summit vent area is inhabited by a thriving population of eels (Dysommina rugosa) that feed on midwater shrimp probably concentrated by anticyclonic currents at the volcano summit and rim. The moat and crater floor around the new volcano are littered with dead metazoans that apparently died from exposure to hydrothermal emissions. Acid-tolerant polychaetes (Polynoidae) live in this environment, apparently feeding on bacteria from decaying fish carcasses. Vailulu'u is an unpredictable and very active underwater volcano presenting a potential long-term volcanic hazard. Although eels thrive in hydrothermal vents at the summit of Nafanua, venting elsewhere in the crater causes mass mortality. Paradoxically, the same anticyclonic currents that deliver food to the eels may also concentrate a wide variety of nektonic animals in a death trap of toxic hydrothermal fluids.
Staudigel
Hubert
H
Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA 92093, USA. hstaudigel@ucsd.edu
Hart
Stanley R
SR
Pile
Adele
A
Bailey
Bradley E
BE
Baker
Edward T
ET
Brooke
Sandra
S
Connelly
Douglas P
DP
Haucke
Lisa
L
German
Christopher R
CR
Hudson
Ian
I
Jones
Daniel
D
Koppers
Anthony A P
AA
Konter
Jasper
J
Lee
Ray
R
Pietsch
Theodore W
TW
Tebo
Bradley M
BM
Templeton
Alexis S
AS
Zierenberg
Robert
R
Young
Craig M
CM
D000818:Animals; D017753:Ecosystem; D004524:Eels; D005290:Ferric Compounds; D055593:Geological Phenomena; D005844:Geology; D006358:Hot Temperature; D008855:Microscopy, Electron, Scanning; D018947:Samoa; D012623:Seawater / Q000382:microbiology; D018707:Volcanic Eruptions
D005290:Ferric Compounds; C000499:ferric oxide