[1] NERC, British Antarctic Survey, Cambridge CB3 OET, England
[2] IFREMER, Ctr Mediterranee, Prov Azur Corse LER PAC, F-83507 La Seyne Sur Mer, France
[3] Univ Plymouth, Inst Marine, Marine Biol & Ecol Res Ctr, Plymouth PL4 8AA, Devon, England
[4] N Carolina State Univ, Dept Civil Construct & Environm Engn, Raleigh, NC 27695 USA