Ffennell, William Joshua (1799–1867), fishery reformer, was born 16 August 1799 at Ballybrado, near Cahir, Co. Tipperary, eldest son (among six sons and ten daughters) of Joshua William Ffennell, country gentleman, and his wife Elizabeth. Educated locally, though not well, he was more interested in leisurely pursuits, especially hunting, fishing, and shooting. In 1824 he purchased the lease for Carrigatha River, which joined Ballybrado on the Suir. This marked the beginning of a passionate concern for fishing interests, and a lifetime of dedication to improving Irish rivers. He became a JP in 1834, and used a combination of charm and cajoling to persuade the local people to stop using stake weirs in the Suir, and refrain from any actions that damaged the river or its fish stocks. In 1837 he became secretary of the Suir Preservation Society, with his friend and neighbour, Richard Butler (1794–1858), 2nd earl of Glengall, as chairman. Important fishing legislation was passed in 1842, 1844, and 1845, and Ffennell was appointed fishery inspector under the board of works. He continued to press for further reform, however, culminating in the passing of significant legislation in 1848, popularly known as ‘Ffennell's act’. This legislation helped protect the salmon industry, providing money and equipment for enforcing previous acts. In recognition of his tireless work, Ffennell was appointed a commissioner on the board of public works with responsibility for the new fishery districts. As he possessed an exhaustive knowledge of the salmon industry, his advice was regularly sought in Britain. In 1860 he was asked to examine the salmon fisheries in England and Wales, and was appointed inspector of salmon fisheries there the following year; he became commissioner of fisheries in Scotland in 1862. His final major contribution to fishery reform in Ireland was a pamphlet (1863) that aimed at ‘effecting a complete renovation of the Irish salmon fisheries’, and vehemently attacked the existing stake weirs. This well-argued case influenced an act which abolished the stake weirs later that year. In 1866 he started a nature magazine, Land and Water, with F. T. Buckland, and in 1864 and 1866 wrote letters to The Times calling for the restoration of salmon fisheries and the protection of rivers against pollution.
He died 12 March 1867 in London. He married (1830) Margaret Catherine, youngest daughter of Robert Prendergast of Greenmount, Co. Tipperary; they had nine children.