A joint founder of the Otter Trust, Jeanne Wayre, who has died peacefully aged 86 at her Waveney Valley home, had a pivotal role in one of the country's most remarkable conservation success stories.

After decades of declining numbers, the otter was heading towards certain extinction until the Otter Trust was founded at Earsham, near Bungay, in 1971 with television naturalist and award-winning conservationist, Philip Wayre.

After 25 years, the Otter Trust's key directors could claim with justification: 'Mission accomplished.' Once harried, by hunting, trapping, pollution and pesticides and unprotected by the law, otters now thrive in every county in England. By 1996, after the Otter Trust had bred and released more than 130 from captive breeding programmes, numbers had recovered to more than 200 in Norfolk alone.

A 1980 survey had shown that Norfolk's population was probably down to 20 or fewer, with a handful in Suffolk. Just two years earlier, their campaign to get the species added to the protected list was successful.

In that same year, 1978, Mr Wayre had made a film, The Vanishing Otter.

Her support for the project was unstinting and especially behind the scenes. She was also interviewed on BBC Radio 4's Woman's Hour to promote the trust's work. Her husband said in 2006 that she had been 'working seven days a week purely for the love of it.'

She was as successful at fund-raising, also for the lifeboats and RNLI at Bungay, as the more practical side of rearing otters. One, called Mouse, which lived in their home, also became popular, especially with publicity efforts. She had reared two of the tame otters, which featured in the Tarka film.

The trust, which opened to the public in September 1976, went on to attract more than 750,000 visitors in the next 20 years and raised funds to continue conservation efforts. One of first releases of breeding otters was on the River Blackwater, Suffolk, in July 1983 and next year into the River Thet, near Thetford. It also included releasing otters bred at Earsham into France and in the Netherlands.

Born at Hessle, near Hull, in the East Riding of Yorkshire, she made rapid progress at school. At 16, she won a state scholarship to Leeds University and gained a first class honours degree in English – at 19. Her first job was as a lecturer in English and linguistics at a polytechnic for foreign students and then she taught at a Leeds school before lecturing at a college in the city.

A lecturer in English at Leeds University, she was involved in the re-organisation of education in Yorkshire. At 38, she became head of a comprehensive school – one of the first in Yorkshire if not the country – with more than 2,000 pupils and 93 staff at Garforth, near Leeds.

She had married Peter Franklin in 1949 and they had three children. She spent 25 happy years in Yorkshire. After divorcing in 1973, two years later she married Philip Wayre.

He had opened the Norfolk Wildlife Park, on a 50-acre acre farm at Hawks Hill, Great Witchingham, in 1961. It was sold in 2000.

When they bought River Farm, Earsham, on the Norfolk bank of the Waveney, with 30 acres of marsh in 1976, they leased 23 acres at a peppercorn rent to the Otter Trust. Later, it acquired other land to start nature reserves including Swangey Fen, near Attleborough, in 1979, and then in 1980, Stanley Carrs reserve, near Beccles. The trust also opened the Tamar Otter Sanctuary in Cornwall in 1986 and a further 230-acre reserve, Bowes Moor, in County Durham, in 1995.

Her contribution to otter conservation around the world resulted in invitations to advise the Italian government and address conferences in Germany. She was also a former chairman of the south regional group of the Norfolk Naturalists' (now Wildlife) Trust.

While otters were central to her life for more than three decades, she enjoyed music, books and especially the literature of Shakespeare, the arts and attending festivals and theatrical productions.

Although her health had declined over the past half dozen years, she took a keen interest in her grandchildren and her great grandchildren.

Her husband Philip survives and she leaves daughters, Felicity and Gillian, seven grandchildren, and six great grandchildren. Her eldest child, Stephen, predeceased in 2007.

A funeral will be held at All Saints, Earsham, on Saturday, December 14 at noon.

Michael Pollitt