Ever since the early meetings of MARECO, the Central Box midway between Iceland and the Azores has stood out as the most fascinating and least known area to visit of the Northern Mid Atlantic Ridge. As far from land as it is possible to be in the North Atlantic Ocean this is where the warm Gulf stream flows from west to east over the ridge. Cold bottom water of Arctic origin flows in the opposite direction through the giant canyons of the “Charlie Gibbs Fracture Zone”.

This is a potential ecological cross roads of the North Atlantic with sub polar species to the north, sub tropical species to the south, American species in the west and European species in the East. The expedition of the GO Sars in 2004 gave us a tantalising first glimpse of what lives here and it is a great pleasure to be finally be at sea on an expedition dedicated to study the ecology in this area.. Our expedition is on board the new UK Royal Research Vessel James Cook built in Norway. With 54 people on board under the command of Captain Antonio Gatti we are heading westwards towards western Ireland seeking shelter in Bantry Bay to carry out crucial pre-cruise calibration of the EK60 sonar that we shall use to measure biomass in the waters overlying the ridge. The ship is stowed full of equipment which is being unpacked, assembled and prepared in time for our arrival at the first station over 1000 nautical miles from our starting point in Southampton.

The ECOMAR project will undertake a comprehensive study of all the processes from water flow over the ridge, primary production in the surface layers, life in the water column, downward flux of organic matter and life on the ridge itself. We are already receiving satellite images of chlorophyll concentration in the study area and have prepared the EM210 sonar that we shall use to survey the sea floor in a very poorly charted area. We have a young scientific party, average age 34 (excluding myself) which will lay the future for a new kind of marine science using the new technology aboard this vessel.

Monty Priede

Principal Scientist

Saturday, 14 July 2007

Hi!

I am a 24 year old Norwegian/French PhD student, currently on the research vessel James Cook, where I will be spending the next forty days. I normally work in the Gatty Marine Lab, at the University of St Andrews.

My goal: investigating the zooplankton on the Charlie-Gibbs fracture zone (CGFZ) of the mid-Atlantic-Ridge (MAR). My contribution to the project is going to be another piece of the puzzle, explaining how surface productivity is affecting the peculiar life of the deep.

I will achieve this by sampling the pelagic (water column) realm, using a RMT (rectangular midwater trawl) which will catch the small animals which rely primarily on currents to move around. My main interest is in euphausiids (krill), a small crustacean which produces bioluminescence and aggregate in large swarms. Their claim to fame is being the principal food-source for large baleen whales. Even though these are not able to swim very quickly, they still migrate to the surface at night and to deeper waters at day. They do this to feed, and to avoid visual predators. This means that krill, and other zooplankton with similar behaviour, can contribute actively to the ecosystem of the deep sea, by feeding on the shallow primary productivity and providing food for abyssal predator and scavengers. I hope to assess the trophic level of krill species, and their main food source, by techniques such as stable isotope and lipid analysis. This will involve freezing samples at -200ºC using liquid nitrogen!

I am also interested in the impact of the unique bathymetry and surmounting fronts of the CGFZ on the species populations. Previous research indicated that deeper individuals tend to be older, so individuals on top of the ridge are usually younger. Is this reflected in the genotype of the species? Studies in other areas suggest that oceanic fronts are a source of genetic divergence. It would be interesting to detect such an effect in our study area, perhaps amplified by the barrier properties of the MAR.

All in all, it looks to be a very interesting cruise, and I can’t wait to get started with the sampling!

Tom Bech Letessier