Born in Yorkshire and educated at Rothwell Grammar School, Fish joined the Royal Naval Volunteer Reserve in 1942 and was posted as a rating to the battleship HMS Duke of York. The following spring he was commissioned as a Sub-Lieutenant on the Fleet Destroyer HMS Marn based at Scapa Flow. He was on at least six Arctic convoys to Russia and subsequently saw service in home waters, the Atlantic and the Mediterranean, ending the war as a lieutenant.
These experiences led him to say that he had seen enough of the ocean for his lifetime. He declined subsequent offers of sea-going opportunities, including a visit to Antarctica when he later became Chairman of the Natural Environment Research Council (NERC), which included the British Antarctic Survey amongst its responsibilities.
After his war service Fish read Chemistry at Leeds University. He then held various posts as chemist, pollution and fisheries inspector, river conservator, Chief Purification Officer, Director of Scientific Services with Essex and Thames water and river organisations. He eventually became chief executive of Thames Water Authority in 1978, a post he held for six years.
He was highly respected for his contribution to the industry both before and after privatisation in 1989, through his innovation, enthusiasm and optimism. He served on several committees dealing with water industry development. These included the Central Advisory Water Committee (1970-72) and the Ogden Committee on Water Authority Management and Structure in 1973.
In this way he was one of the architects of the modern UK water industry. In 1974 many hundreds of local authority water and sewerage functions were brought together within defined river basin boundaries to create 10 water authorities. This river basin model for effective water management is increasingly being used around the world.
The benefit of his experience and views on freshwater management and fisheries were in demand worldwide. He made a number of professional visits overseas, notably to China and Poland. In 1976, during his time at the Thames Water Authority, he had been appointed to the board of the NERC and in 1984 he was made chairman for a term of four years.
Fish was adept at instilling optimism, in finding solutions to difficult resource problems, in causing others to believe that his organisation mattered and that the seemingly impossible might just be achieved. He would not shy from showmanship to achieve his aim. "Bring a research ship into the Pool of London and invite their Lordships and Members of Parliament by launch from Westminster so that NERC's name will be imprinted on their memories" was a typical suggestion - and a successful one.
He loved science and recognised that to achieve high quality science required a subtle blend of a strategic sense of direction and individual scientific creativity, allied with the provision and management of large- scale equipment and computing. He attended to all aspects and at the end of his term as chairman the council gained considerable plaudits for developing relevant and nationally important research. Increased funding followed and suggestions for disbanding the council were discarded. It is heartening that the NERC is thriving still and due in no small measure to Fish's contribution.
Fish, who was knighted in 1989, became a member of the Advisory Committee, and then of the Board, of the National Rivers Authority, set up at the time of water privatisation. As ever he brought sound experience and common sense, presented in a forthright but often humorous way, to the proceedings of the new environmental regulator.
In previous posts in the water industry he had been both poacher and gamekeeper in the same organisation - as chief executive of Thames Water Authority, he was responsible for providing water services, and also for regulating them. This experience enabled him to know very well the poachers' tricks, and he was an excellent gamekeeper. Very recently he was involved, as Chairman of Enviro-Logic Ltd, in establishing the first new water company since privatisation. Its subsidiary, Albion Water, has just gained a contract to supply water to a large industrial user within the area supplied by another water company. This precedent may well be extended to other water users and to waste water handling.
Allied to his work, Fish was involved with related professional bodies, including the Freshwater Biological Association at Windermere and the Institute of Water and Environmental Science, of which he was President in 1984. At the time of his death he was President of the Institute of Fisheries Management and a Visiting Professor of the University of Hertfordshire. He was a Fellow of the Royal Society of Chemistry and of the Institute of Water and Environmental Management.
Hugh Fish was that unusual combination for his generation of a scientist with business management skills. He was an optimist whom some misjudged, at their peril, because of the fun he brought to serious matters. He was a professional achiever and encouraged others to emulate himself. Though devoted to tasks related to the water industry, he also found time for and cared deeply about his family. He married Nancy Asquith in 1943 and they had two sons and a daughter, who were a source of great pleasure to them. Sadly one son predeceased him.
Hugh Fish, water and environmental manager, and chemist: born Woodlesford, Yorkshire 6 January 1923; Pollution and Fisheries Inspector, Essex River Board 1952-65; River Conservator, Essex River Authority 1965-69; Chief Purification Officer, Thames Conservancy 1969-74; OBE 1971, CBE 1984; Director of Scientific Services, Thames Water Authority 1974-78, Chief Executive 1978-84; Chairman, Natural Environment Research Council 1984- 88; Kt 1987; President, Institute of Fisheries Management 1987-99; Chairman, Water Engineering Ltd 1988-91; married 1943 Nancy Asquith (one son, one daughter, and one son deceased); died Wallingford, Oxfordshire 27 May 1999.