A team of scientists has just returned from a research mission to sample habitats on the edge of the continental shelf using the Marine Institute’s vessel, the RV Celtic Explorer, and the deep water remotely operated vehicle (ROV) Holland I. The aim of this mission was to explore the little-studied habitats at the edge of the continental shelf, where the depth increases from approximately 400 m to over 3 km.
The ROV Holland 1 uses its robotic arm to take a sample of deep water sponge from the deep ocean along Ireland's continental shelf. Picture by NUIG, Copyright Marine Institute.
In addition to mapping sections of habitat, material sampled from the ROV and from cores was passed to taxonomists to help quantify the biodiversity and identify any species that may be new to science. Some sampled organisms will be frozen and returned to the biodiscovery laboratory hosted by the Marine Institute so that they can be made available to researchers looking for new compounds with pharmaceutical potential.
'Biodiscovery' is the term used to describe the collection and analysis of organisms for the purpose of developing new products. Most of the new compounds derived from marine organisms have originated in warm water ecosystems such as coral reefs. To date, relatively little effort has been spent studying bioactivity in temperate waters and the deep sea, despite the abundance here of sponges and other groups known to have great potential for biodiscovery.
The deep sea sponge Lissodendoryx diversichela (white) just above a patch of coral photographed from the RV Holland 1. Picture by NUIG. Copyright: The Marine Institute.
“A feature of the continental margin is the presence of canyons, which increase the complexity of the margin and may be areas of high biodiversity,” said Project Leader Prof. Mark Johnson of NUI Galway. “Up until quite recently, it has been difficult to sample canyons. Deep sea communities are normally sampled by sending down metal grabs or dredges. These methods do not work well in sloping complex habitats like canyons. In contrast, an ROV can manoeuvre to video and sample organisms with a high degree of precision.”
Samples from the ROV were mostly collected on, or close to, underwater cliffs, some of which were over 100 m high. This sampling included the deepest dive to date with the Holland, to just short of 3000 m deep, twice the depth of the sea floor at the site of the Deepwater Horizon oil leak in the Gulf of Mexico. Organisms were collected using the robotic arms of the ROV, sometime using a suction hose to draw material into a collection box. On surfacing, the collected material was sorted, with material for biodiscovery frozen at minus 80 °C, the best way to preserve the molecules of interest.
The ROV Holland 1 being deployed (Photo Christine Picton). The cylindrical structure on top of the ROV is the 'tether management system' that the ROV detaches from once its operational depth is reached. The crew member in the bottom right of the picture gives an idea of scale.
To make the best use of the mission, the scientific team was drawn from several institutes: NUI Galway, University College Cork (UCC), Trinity College Dublin (TCD) and Queen’s University Belfast (QUB). The Chief Scientist was Dr Louise Allcock from NUI Galway. (Picture left: Christine Picton of QUB holding a piece of dead coral with a vase-shaped sponge attached. The sample was picked up using the robotic arm of the ROV. Photo: Karl Bredendieck).
Scientists from UCC are interested in the biodiscovery potential of microorganisms from sponges. This work is complemented by microbiologists from Galway working on the composition and function of microorganisms in the water column. The Trinity team are looking at the links between the canyon habitats and the cycling of nutrients.
Queen’s University Belfast researchers are interested in biodiversity, particularly the taxonomy of sponges. Links to the wider international research community have been made through associating this mission with the Census of Marine Life COMARGE project (http://www.ifremer.fr/comarge/en/index.html).
This mission is partially supported by a Beaufort Marine Biodiscovery Research Award under the Sea Change Strategy and the Strategy for Science Technology and Innovation (2006-2013). The Beaufort Award is a 7-year project linking NUI Galway, UCC and QUB. It provides the human capacity to support this mission, including PhD studentships and postdoctoral appointments.
Angela Stevenson (TCD) making detailed photographs of a deep-water holothurian or "sea cucumber" (Psychropotes sp.) retrieved from 2800 metres by the ROV. (Photo by Carsten Wolff)
The overall aim of the Beaufort awards is to develop Irish research capacity in five key areas identified in Sea Change, including Marine Biodiscovery, Ecosystem Approach to Fisheries Management, Sensors and Communications Systems for the Marine Environment, Fish Population Genetics and Economic Research related to Development Dynamics of the Marine Sector in Ireland. These awards are managed and supported by the Marine Institute, and funded under the Marine Research Sub-Programme of the National Development Plan 2007–2013.