Mountains in the Sea 2004: Exploring the New England Seamount Chain
May 8-24, 2004
Visiting a seamount is a special event, but returning to a previously visited seamount is exceptional. Second opportunities are rare, because seamount exploration requires costly resources, such as research submarines or remotely operated vehicles (ROVs), and scheduling is tight. So, for these and other reasons, we are excited about returning to the three seamounts we visited last August on Mountains in the Sea 2003.
The first exploration of any undersea site produces many questions and almost no answers.
Last year, we saw that all three seamounts—Manning, Kelvin, and Bear—had spectacular octocoral gardens. We collected octocoral (coral with eight featherlike tentacles) specimens for reproductive condition and genetic analysis, and we found that a diverse array of commensals (organisms that benefit from a harmless relationship with another species) live with these corals. The commensals apparently use the corals for substrate and help in getting food; they may also require the corals to expend small amounts of energy.
Anticipating interesting patterns in coral distribution, we took long video sequences to document the coral abundances up the side and over the top of the seamounts. The video also enabled us to look at other wildlife, such as deep-sea fishes, and to determine whether they use the corals for food or shelter. In another effort, we set out bare blocks of basalt (volcanic rock) to see if we could collect newly settled coral colonies.
This year, the team will continue to video, completing comprehensive transects around several other sides of the seamounts. We aim to document the occurrences of the corals with respect to current flow. We also plan to observe the relationships of the benthic (bottom-dwelling) fishes to coral distributions as well as to other aspects of the seamount landscape. Additionally, we will recover the basalt settlement blocks, determining whether any young corals have settled here in the last 10 months, and sample extensively for population analysis of commensal species. We know from our analysis of last year's images that many coral species remain to be collected and identified. So, this time around, we will dedicate much effort to documenting the octocorals of the seamounts.
Updates & Logs
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