Sir Cyril Lucas

Cyril Edward Lucas, marine biologist: born Hull 30 July 1909; FRSE 1939; Director of Fisheries Research, Scotland (Department of Agriculture and Fisheries for Scotland) and Director, Marine Laboratory, Aberdeen 1948-70; CMG 1956; Chairman, Consultatove and Liaison Committees, International Council for the Exploration of the Sea 1962-67; FRS 1966; Chairman, Advisory Committee on Marine Resources Research, FAO 1966-71; Kt 1976; married 1934 Sallie Rose (died 1974; two sons, one daughter); died Aberdeen 12 January 2002.

Cyril Lucas was a marine biologist of distinction who laid the foundations for modern fisheries science around the world. Through his role as Director of Fisheries Research for Scotland – from 1948 to 1970 – and as a participant in international fishery councils and commissions he shaped the mechanisms, still used today, for providing scientific advice on fisheries.

Lucas began his research career at the University College of Kingston-upon-Hull, his native city, working with Alister Hardy, the Professor of Zoology and Oceanography, on plankton research. Plankton, tiny creatures which drift in the currents of the sea, can "bloom" and multiply to form dense concentrations which, spread over large areas, support all the life of the sea from the smallest fish to the great whales. Hardy and Lucas understood that determining the quantities and types of plankton in the sea, and relating this to the various factors which influence them, is the key to understanding the productivity of the oceans.

Hardy and his team devised the continuous plankton recorder, a torpedo-shaped machine which could be towed at full speed behind any ordinary ship. Like a giant coil of gauze at the end of several hundred miles the material can be unwound inch by inch to reveal plankton distribution.

Hardy and Lucas arranged for the continuous plankton recorder to be deployed routinely by cargo and other commercial vessels operating on routes across the North Sea and beyond. In 1932, the year after Lucas graduated, a five years' trial began over the southern half of the North Sea, on lines radiating from Hull to the Skagerak, to Hamburg and to Rotterdam. Month by month, continuous records were obtained showing variations in the density of plankton across the North Sea. These could be compared throughout the year, and from year to year and related to ocean weather conditions and to the distribution of other organisms – including fish. The survey was extended over the whole of the North Sea, and in 1937 a branch of the Hull Oceanographic Laboratory was opened in Leith, near Edinburgh, with Cyril Lucas in charge.

The onset of war in 1939 saw the cessation of the survey and the start of a fruitless project to put plankton on the menu at a time of shortage. After a death-defying experience attempting to "harvest" the tiny creature Calanus, Lucas's great scientific expertise was redirected to find the best ways to prevent the infestation of stored wheat by weevils.

Despite his personal research on marine science's having been interrupted, Lucas recognised that the war did provide what he described as the second of two gigantic fisheries experiments, demonstrating that the removal of fishing resulted in a rapid regeneration of declining fish stocks.

In 1946 he returned to marine science to put together a new programme of sampling with the continuous plankton recorder. This important work continues today and is now based at the Sir Alister Hardy Foundation for Ocean Science, at Plymouth.

Lucas published his best-known and most quoted paper in 1947: "The Ecological Effects of External Metabolites". He had noticed, with others, the scarcity of fish and other organisms in the presence of dense phytoplankton. He suggested that this "animal exclusion" was the result of the production of substances or "ectocrines" which had an inhibitory or even lethal effect upon some associated organisms, but were beneficial to others. He pointed out that some of the underlying principles were shared with antibiotics. During the course of evolution many organisms had adapted themselves to tolerate or take advantage of the external metabolites of their neighbours. Others had not and took avoidance measures. He proposed that important ecological mechanisms might have arisen in this way.

In 1948 Lucas was appointed Director of the Scottish Home Department Marine Laboratory in Aberdeen. He became responsible for providing scientific advice to government on the marine fisheries and for research into the fish stocks, including salmon.

Although the laboratory at Aberdeen was small and cramped, seagoing facilities were good, with an old but seaworthy steam trawler, the Explorer, and a smaller vessel, the Kathleen. A half-share was acquired in a wooden herring drifter, shared with the Lowestoft laboratory, and a larger steel naval vessel was converted into a research ship and renamed the Scotia. Later, in 1955, a new purpose-built research ship joined the fleet from the shipyard of Alexander Hall & Co in Aberdeen to replace the Explorer, and in the same year a new laboratory building was opened in the city's Torry village.

Lucas led a laboratory which in his 22 years in harness rapidly increased in size and international reputation. In 1958, he also became responsible for the Freshwater Fisheries Laboratory at Pitlochry, the former Brown Trout Research Laboratory. He reorganised and extended the research programmes of both laboratories and recruited a large number of young fishery scientists and oceanographers, many of whom have since gone on to create their own successes, and to direct their own laboratories.

Cyril Lucas was not only an outstanding director of fishery science, but also played a prominent role in the international aspects of fisheries management. He had realised that the increasingly sophisticated mathematical models being developed for describing the dynamics of fish stocks, and assessing the effects of fishing were without value unless they were accompanied by a wide and detailed knowledge about the fish stocks and the fisheries themselves.

As early as 1901 Scotland had set an example to other countries by collecting statistics of individual trawl catches, based on squares of latitude and longitude which are now the internationally recognised statistical units. Scottish scientists also played a key part in establishing the International Council for the Exploration of the Sea (ICES) founded in 1902. The truly international nature of many fish stocks meant that marine research could only be successful if it was co-ordinated internationally.

Lucas put much of his energy into ICES, the fisheries work of the Food and Agriculture Organisation of the United Nations, the International Commission for the Northeast Atlantic Fisheries and the Intergovernmental Oceanographic Commission. His efforts were supported by the outstanding Scottish Fisheries Secretary of the time, John Aglen. The two of them worked together to build sound international arrangements for providing scientific advice on the fisheries of the north-east Atlantic.

To those who worked with him Cyril Lucas was modest, quietly spoken, quick to smile, but firm and with a strong sense of direction. He remembered almost everything he was told, which served him well in the relentless committees he served. He was an unashamed pipe-smoker and in recent years walked on most mornings along Union Street in Aberdeen to drink coffee and read the newspapers in Fraser's Department Store, one of the few cafés still tolerating pipe-smokers.

Tony Hawkins