SAMS news room

by Dr Toby Sherwin, Principal Scientific Officer

Tuesday, 18 October 2005

Four SAMS scientists and colleagues from the National Oceanography Centre, Southampton, the Universities of Aberdeen and East Anglia, the Environmental Research Institute Thurso, and the Sea Mammal Research Unit passed Britain's most famous rock during a current research cruise along the Ellett Line on RRS Charles Darwin.

The Ellett Line, called after its founder, the late David Ellett, is a time-series established 30 years ago that monitors environmental changes off the western coast of the UK. This region is anomalously warm for its latitude, and climate-driven changes here may thus directly impact on UK weather patterns.

Cruise CD176 is a multidisciplinary cruise combining CTD, nutrient and dissolved oxygen measurements with determinations of trace metal concentrations, and biological monitoring of seabed biology and cetaceans.

Our seabed sampling has three objectives: to a) repeat five cores at 2900 m in the Rockall Trough, sampled in 1975 by the late Professor John Gage; b) sample at 1000 m on either side of the Wyville Thomson Ridge to replicate previous samples; and c) find more specimens of a deep-sea acorn worm on the north side of the WTR. The last objective has already been met.

When steaming between CTD stations an underwater microphone is towed behind the ship to listen for whales, dolphins and porpoises, so that we can map their distribution and relate it to the oceanographic data we collect. Sperm whales, dolphins and pilot whales have been providing their usual cacophony of clicking, whistling and buzzing for over 50% of the listening time, much more than is usually detected.

A team of biogeochemists from Southampton are investigating iron biogeochemistry.  Samples for dissolved iron are being collected using a near-surface clean underway fish and titanium CTD. On deck incubations are undertaken to determine if iron is a potential limiting micro-nutrient for primary production in the high latitude north Atlantic (Icelandic basin).

The scientific team on the RRS Charles Darwin are: