Britain's foremost marine fisheries ecologist, David Cushing, did much to transform the subject into a science, in a career of more than 50 years.

David Henry Cushing was born in Alnwick, Northumberland, and educated at Duke's School, Alnwick, and Newcastle upon Tyne Royal Grammar School before going to Balliol College, Oxford, where he took his MA and in 1950 gained his DPhil.

After war service in the Army from 1940 to 1946 he joined the Fisheries Laboratory, Lowestoft, now the Centre for Environment, Fisheries and Aquaculture Science (Cefas), in 1946 as a scientific officer. There he rose to become deputy director and head of the fish population dynamics division from 1974 until his retirement in 1980.

He was active in the International Council for the Exploration of the Sea (ICES), serving on the advisory committees on fisheries management and marine pollution, chairing the biological oceanography committee and leading the herring working group through a critical phase in its existence. His achievements were recognised in his election to fellowship of the Royal Society, and through many awards from institutions overseas.

His books included Marine Ecology and Fisheries (1975) in which, for the first time, the whole of fisheries science - the observation and modeling of primary and secondary production, the unity of fish stocks and the population dynamics of fishes, the temporal changes in their physical and chemical environments and thus the regulation of fish populations by nature and man - is laid out in a modern comprehensible text.

Cushing was in the forefront of the development of fisheries acoustics from the late 1940s; of studies of production in the sea; of research into why North Sea herring declined from 1955; and he took a pioneering interest in the impact of climate on the planktonic ecosystem and on fish stocks.

The theory of fisheries acoustics and the equipment to support and develop it were both in their infancy after the war. As Cushing's research team began their work in the early 1950s, ring-netters were estimating the density of herring shoals from the number of hits on a towed piano-wire. There was still no quantitative evidence as to which part of a fish (flesh, bone or swimbladder) produced the acoustic return; no knowledge of which frequencies produced the optimal return; no information as to how the packing density of the fish, or how their depth or the thermal structure of the water might affect the amplitude of the return.

Cushing answered all these points in sequence. A milestone paper by Cushing and Richardson in 1955 showed that more than 50 per cent of the acoustic return from fish is from the swimbladder.

Cushing's second main research interest was the controls on production in the sea, to which he made key contributions, through studies, conducted on 13 cruises between March and June 1954 off the northeast coast of England, and published in 1963.

At that time, what might be called the “agricultural model of marine production” - the notion that the quantity of algae produced depended solely or largely on the quantity of available nutrient - was already under fire, notably from the research done at the marine biology laboratory at Plymouth in the mid-1930s, which had shown that a large part of algal mortality during the production season must be due to zooplankton grazing.

The monitoring of the full range of production parameters throughout the complete production cycle by Cushing in 1954 confirmed that the algal stock was being restrained primarily by grazing, not by nutrients. Three key reports, published almost together in the early 1960s by Menzel and Ryther (1960), John Strickland (1961), and Cushing and co-workers (1963) effectively modernised the subject of production in the sea at a stroke.

In 1955 the first great crash of the East Anglian herring fishery took place when the forecast numbers of young recruits failed to arrive. This collapse, which had devastating effects on the East Anglian and Dutch economies, led to urgent national and international inquiries as to its cause.

At Lowestoft Cushing was drafted in to take an objective, scientific and quantitative view of the arguments of the different factions there, which centred on the extent to which the collapse might be due to a Danish industrial fishery for juvenile herring on the Bløden Ground of the eastern North Sea.

The first international scientific meeting on herring in the Downs did not succeed in sustaining the case that the reduction in catch might be due to increased fishing effort - but it was a milestone in the development of international co-operative research, and it shaped new responsibilities for ICES. In meeting after meeting Cushing as chairman pressed the need to obtain estimates independent of catch-andeffort data. Homing in on the two key questions (What is the fishing mortality on the adult stock? What is the fishing mortality on the juvenile stock?), plans were laid to measure fishing mortality by tagging the adults on the Downs spawning fishery and juveniles on the Bløden, the first such use of the method on herring. These internationally sponsored tagging experiments were later successfully complemented by a large-scale programme, initiated by Cushing, in which high-speed samplers were used to catch herring larvae directly.

Cushing introduced the concept of “recruitment overfishing” by which the parent stock is reduced to a degree that recruitment suffers. But around a constant stock size, recruitments are extremely variable. This led him into the study of climate and its effects, which became his fourth and most enduring area of research.

The wealth of ideas he produced continues to lead research today. His 1973 “match-mismatch hypothesis” to explain the natural regulation of fish populations in terms of the timing of larval production and their food is perhaps his finest construct.

Cushing's official retirement merely ushered in a new and equally productive phase of his long career. In 1979 he established the Journal of Plankton Research which he edited for 22 years until 2001.

Cushing is survived by his wife, Diana, whom he married in 1943, and by their daughter.

David Cushing, FRS, deputy director, Fisheries Research, England and Wales, 1974-80, was born on March 14, 1920. He died on March 14, 2008, aged 88