Professor Sir Eric Denton

Brilliant marine biologist who led the MBA Plymouth laboratory

Eric James Denton, marine biologist: born Bentley, Yorkshire 30 September 1923; staff, Biophysics Research Unit, University College London 1946-48, Fellow 1965; Lecturer in Physiology, Aberdeen University 1948-56; physiologist, Marine Biological Association Laboratory, Plymouth 1956-74, Director 1974-87, Research Fellow 1987-2005; FRS 1964; Royal Society Research Professor, Bristol University 1964-74, Honorary Professor 1975; member, Royal Commission on Environmental Pollution 1973-76; CBE 1974; Kt 1987; married 1946 Nancy Wright (two sons, one daughter); died St Just, Cornwall 2 January 2007.

Eric Denton was one of the most brilliant experimental marine biologists of the past century. He worked on a wide range of fundamental problems from a biophysical perspective, with the common threads of communication and locomotion in the sea, covering areas such as buoyancy, eyes and vision, perception, camouflage and signalling.

An imposing individual, he was a mentor to many biologists working not only in his field but also in the wider marine and geochemical sciences. The combination of these attributes with his scientific passion gave him the qualities of a great scientific leader.

Born in Yorkshire in 1923, Denton was educated at Doncaster Grammar School and St John's College, Cambridge, where he read Physics. Toward the end of the Second World War he worked at the Radar Research Establishment, Malvern, a career step that he shared with several renowned biophysicists. He joined the group of Professor A.V. Hill in the Biophysics Research Unit at University College London in 1946. This laboratory produced some of the world's best physiologists. Denton took a Lectureship in Physiology at Aberdeen University in 1948 before moving to the Marine Biological Association (MBA) laboratory in Plymouth as a staff physiologist in 1956.

Thus began a long and distinguished career in experimental marine biology. He was awarded a Royal Society Research Professorship, seconded from Bristol University, and became Director of the MBA Plymouth laboratory in 1974. He was also a member of the Royal Commission on Environmental Pollution in 1973-76. After retiring in 1987 he continued to work at the MBA laboratory as an Honorary Research Fellow for almost 15 years.

Eric Denton had several outstanding features as MBA laboratory director. He interacted with the staff of around 100 not through formal management or even regular scientific discussion meetings but mainly by "calling in" on individuals around the laboratory or during coffee and tea breaks in the common room. This approach, focusing on individual interactions, reflected his genuine interest in the work of all members of the laboratory in a range of areas from membrane biophysics to ocean chemistry. These interactions rarely ended without him making some constructive comments or raising important questions.

At a personal level, his quietly spoken manner was in complete contrast to his scientific presentations in front of an audience which were always crystal clear. He also worked well with the governing council and president while steering the laboratory through the vagaries of Research Council funding. During this time, the MBA flourished both through its in-house research and that of many visiting workers.

Many of these visitors were physiologists, including P.F. Baker and R.D. Keynes who focused their attention on the biophysics of the giant nerve fibre of the squid and D. Haydon who studied the mechanism of anaesthetic action, using the same system. This followed the discovery of this specialised cell by J.Z. Young, which had led to Nobel Prize-winning work at the MBA by Sir Alan Hodgkin and Sir Andrew Huxley on the nature of the nerve impulse and membrane ion channels. While Denton began to work on aspects of squid physiology, his individual approach soon led him down new avenues of marine biology.

Denton's early work identified new visual pigments in amphibians, reptiles and fish. He later showed the importance of the silvery layers in the eyes, the luminescent organs and external surfaces of fishes. His unique experimental approach to problems led to important insights, gained by the careful study of often common creatures. Such insight led to the discovery that the distribution of light in the sea made it possible for fish to camouflage their sides with mirrors provided by their silver scales, making themselves invisible to predators. More complex and sophisticated methods of camouflage were revealed during ocean cruises on the research vessel RRS Discovery, along with various other significant findings on how deep sea fish use light to search for prey.

These investigations were made possible by Denton's superb command of optics and ability to design experiments and construct simple apparatus to make measurements that had not been possible previously. It was on a Discovery cruise, too, that he found a dragonfish (Malacosteus) that could illuminate prey with a luminescent searchlight that used a wavelength of light that the prey could not detect. Denton held the firm opinion that experimental biology should not necessarily be confined to the laboratory. Indeed, it was an unwritten rule that young scientists joining the Plymouth laboratory should spend some time at sea, a philosophy that persists to this day.

Another major contribution was in the field of buoyancy of fish and cephalopods. This work revealed an astonishing range of mechanisms by which different fish and cephalopods can regulate their buoyancy.

For example, in collaboration with M.R. Clarke and J.B. Gilpin-Brown, Denton showed that many squid, including the giant squid Architeuthis, use bags of ammonium chloride rather than the air-filled swim-bladders used by bony fish to regulate their buoyancy. He demonstrated that cuttlefish used their cuttlebone as an adjustable buoyancy device, a result that allowed the locomotion and behaviour of modern and long-extinct nautilids and ammonoids and belemoids to be understood. Moreover, he showed that many deep-sea dogfish sharks and basking sharks used especially light oil to regulate their buoyancy.

Some of Denton's most elegant experiments were on the perception of distance and direction of sound by fish. Combining his experimental and theoretical talents with the electrophysiological expertise of Sir John Gray, he showed a close and previously unknown coupling between the swim-bladder and ear that is a special feature of clupeoid fishes such as herring and anchovies.

Denton's home in St Germans, Cornwall, was familiar to many visiting scientists and resident staff of the laboratory who enjoyed the exceptional hospitality that he provided together with his wife Nancy. This hospitality was an important component of the ethos and family atmosphere that Eric Denton instilled in the laboratory, a major role of which was to provide research facilities for visiting marine biologists from postgraduate students to world-leading scientists.

He received many honours, including the Royal Society's Royal Medal in 1987 and the International Prize for Biology by the Japanese Society for the Promotion of Science in 1989. Despite increasing difficulties with movement and communication brought about by Parkinson's disease he continued to supervise PhD students and to work in his laboratory, publishing his results in leading journals long into his retirement. He made a final visit to the laboratory last summer.

Colin Brownlee