A coral complex from Manning Seamount

A coral complex from Manning Seamount featuring the octocoral Candidella imbricata, and the hard corals Lophelia pertusa and Desmophyllum cristagalli, the latter in both living and fossil forms. Click image for larger view and image credit.

North Atlantic Stepping Stones 2005

August 7 - September 3, 2005

Seamount chains are present in all ocean basins, potentially providing stepping stone habitats that are semi-continuous and are likely to have a fundamental impact on the faunal dispersal patterns controlling regional biogeography and the diversity of deep-sea fauna. Identifying the mechanisms that drive the distribution and evolution of deep-sea species in space and time is critically important to understand the forces that structure deep-sea biodiversity.

The New England seamount and Corner Rise seamount chain comprise a line of seamounts that extend from the eastern continental margin of the United States to the Mid-Atlantic Ridge. The New England Seamount Chain, the Corner Rise Seamounts, the mid-Atlantic Ridge, and the deep sides of the Azores platform constitute a nearly continuous series of hard substrate islands in a sea of abyssal mud extending across the North Atlantic Ocean. Major peaks rise as much as 4000 m above the abyssal plain. While the geology of the seamounts and their effects on ocean currents have been studied to some extent, the evolutionary and ecological exploration of these important habitats have only recently been addressed.

Together, our group has conducted three cruises to the western part of the New England Seamount chain using Alvin, Hercules/Argus, and the autonomous vehicle ABE. Video transects and discrete samplings have revealed habitats in which discovery of new species and range extensions from distant locations are common. The results of our explorations to date have produced tantalizing clues about how seamount faunas are distributed on individual peaks and how they are restricted to particular regions of the ocean by current patterns. But this work remains incomplete. Almost none of the seamounts we will visit has been biologically sampled by submersible or ROV before.

In order to develop a more complete understanding of patterns in the diversity and abundance of corals, the species that live in association with them, and deep-sea nekton of seamount habitats in the western North Atlantic, we are targeting the Corner Rise and western New England Seamount regions, a nearly 3,000 km-long transect across the NW Atlantic Ocean Basin. Our ultimate goal is to ascertain if seamounts function as 'stepping stones' allowing hard substrate organisms to disperse among these deep-sea 'islands' and expand their ranges across ocean basins. The Hercules/Argus ROV system will be our primary sampling tool in order to obtain high resolution imagery and discrete faunal samples from particular sites. Multibeam sonar will be used to aid in dive planning and to better understand variation in seamount morphologies and landscape patterns. These remotely-operated dives will provide seafloor samples and observations from critically important sites to assess the role of the New England and Corner Rise Seamounts in controlling the biogeography, diversity, and evolution of deep-water corals and other fauna in the North Atlantic. In addition, using experience gained from our previous Ocean Exploration and NSF funded cruises, we will develop a comprehensive educational facet that will focus on the collection and compilation of educational resources for teachers.


Updates & Logs
Click images or links below for detailed mission logs.

September 3, 2005 September 3, 2005 A novice crewmember on the expedition shares her once in a lifetime experiences.

September 1, 2005 September 1, 2005 Will the real Lepidisis please stand up? The problem of cataloguing deep sea corals.

August 31, 2005 August 31, 2005 Seamount larva are tiny creatures dependent ocean currents for their survival.

August 30, 2005 August 30, 2005 Paula Carlton, Teacher at Sea, shares her excitement at being onboard a research vessel and discovering new territories.

August 28, 2005 August 28, 2005 The expedition is moving westward, toward the New England seamounts. But not before a memorable dive yielding still more new discoveries.

August 26, 2005 August 26, 2005 Maintaining and operating the ROVs Hercules and Argus during a weeks-long research cruise requires time and teamwork. Read about the details.

August 24, 2005 August 24, 2005 Scientists use the ROV Hercules to census fish, as well as corals, on the challenging seamount terrain.

August 22, 2005 August 22, 2005 More biogeographic information is collected at the Central Corner Rise Seamounts. What can these faunal differences tell the scientists?

August 20, 2005 August 20, 2005 How does the science party decide where to dive when an area is unexplored? Read about the process that is as much art as science.

August 18, 2005 August 18, 2005 The diving at East Corner Rise wraps up, resulting in improved maps, a new name for the underwater feature, and some interesting coral observations.

August 15, 2005 August 15, 2005 Journey into the past as the scientists honor the 71st anniversary of the dive made by William Beebe and Otis Barton one-half mile under the sea in their bathysphere.

August 14, 2005 August 14, 2005 Groomed poodles and bottlebrushes? Could these be real names for corals? Read how scientists use inventive substitutes for scientific names while onboard. Includes slide show.

August 12, 2005 August 12, 2005 Read about the challenges of studying reproduction in deep-sea corals on seamounts so remote and unexplored they have yet to be officially named. Includes slide show.

August 10, 2005 August 10, 2005 Read about the coordination required each time the ROV dives and the "shopping list" scientists make so that they hopefully get the most of each dive.

August 8, 2005 August 8, 2005 North Atlantic Stepping Stones is getting underway. Read about the challenges facing scientists preparing for the second of back to back explorations. Includes slide show.