Larval settlement arrays E and F are readied for deployment at Cloud vent, marker N-6. A spider crab in the foreground is checking them out.

NOAA Ship Ron Brown/ROV ROPOS
Science News

Science Report - Friday, July 27, 2001
Bill Chadwick
Ship's position: 45 56.0'/-129 58.9'

ROPOS dive 629 involved extensive use of the elevator mooring to get equipment and samples down to the seafloor and back up again. Most of the elevator cargo was larval traps and settling arrays, which are both tools used to investigate how vent animals colonize new sites. Larval traps collect animal larvae that is floating by in the water, whereas the setting arrays collect larvae after they have settled out of the water, attach themselves to a substrate, and start to grow into juveniles. Little is known about how vent animals reproduce and spread, but they are remarkably successful, considering that hydrothermal vent sites are ephemeral and often far apart. Traps and arrays were recovered today from the Cloud vent area that had been deployed for 1 week, and additional settling arrays were put down which will be left in place for 1 to 2 years at varying distances from the vents. With less than a week remaining in the NeMO 2001 expedition, the schedule for the coming days is full of recoveries of short-term experiments and deployments of long-term ones for the coming year.