Nicholas Hughes, the son of the poets Sylvia Plath and Ted Hughes, has hanged himself at the age of 47. The former fisheries scientist at the University of Alaska Fairbanks had carved out a successful scientific career in one of the remotest parts of the western world, but ultimately he could not escape the legacy of being the offspring of one of the most famous and tragic literary relationships of the 20th century.

Those who know little else about his mother know that she was the American-born poet who gassed herself in the kitchen of her north London home in February 1963 while her one-year-old son and his two-year-old sister, Frieda, slept in their cots in a nearby room. Plath had placed towels around the kitchen door to make sure the fumes did not reach her children. She had been distraught at the break-up of her relationship with Hughes, following her discovery of his infidelity. Six years after their mother's death, in 1969, their father's then partner, Assia Wevill, also killed herself, killing her four-year-old daughter Shura in the process.

Plath's relationship with the future poet laureate has been the subject of numerous literary and personal memoirs and biographies, and even a film, as well as long-running attacks on her husband's reputation and behaviour by some feminists. She addressed one of her last poems, Nick and the Candlestick, to her baby son: "O love, how did you get here? O embryo … In you, ruby/ The pain you wake to is not yours … You are the one." Although Nicholas Hughes's father maintained an anguished public silence about the tragedy, poems written at the time, published in the last year of his life, also spoke of his relationship with his son.

In a statement issued late on Sunday evening, Frieda Hughes reported: "It is with profound sorrow that I must announce the death of my brother Nicholas Hughes, who died by his own hand on Monday 16 March 2009 at his home in Alaska. He had been battling depression for some time.

"His lifelong fascination with fish and fishing was a strong and shared bond with our father (many of whose poems were about the natural world). He was a loving brother, a loyal friend to those who knew him and despite the vagaries that life threw at him, he maintained an almost childlike innocence for the next project or plan."

A report in the Fairbanks Daily News-Miner today by its columnist Dermot Cole understandably celebrates Hughes's academic and personal qualities rather than his literary associations. Noting that his initial scientific training had been at Oxford, Cole says he earned a doctorate at the University of Alaska in 1991: "He made lasting friendships in Fairbanks with those who shared his inventive interests in such varied pursuits as stream ecology, pottery, woodworking, boating, bicycling, gardening and cooking the perfect pecan pie … He spent countless summer hours in his research of grayling and salmon in the Chena river, exhibiting all the patience and wonder that defines a great fisherman. One of his innovations was rigging underwater cameras to get a three-dimensional view of the fish feeding in the passing current."

That interest may seem to pop psychologists an altogether more positive inherited legacy, of Ted Hughes's passionate interest in fishing, and indeed his father made several visits to Alaska before his death in 1998. Nicholas's particular academic specialism was in the behaviour of fish in currents. A 2004 paper explored why larger fish swim upstream in the turbulence of midstream rather than in the quieter waters near the banks: "Large fish swim further from the bank to avoid wave drag, the resistance associated with the generation of surface waves when swimming close to the surface," he wrote.

Hughes gave up his professorship two years ago to concentrate on pottery, although the paper said he continued his research with his partner, Christine Hunter, also a biologist.

Cole wrote: "A few times I called to let him know I would like to write about his life and his family connections whenever a news story about his parents appeared, but he did not think it was a good idea, so it never happened. He deserved his privacy. By and large, people in Fairbanks respected that, which is a good comment on our part of the world. In Alaska he had the freedom and the opportunity to live on his own terms and be recognised for his own accomplishments. Here he was not a literary figure forever defined by the lives of his parents."

In Plath's poems, he was her saviour

The shock and sadness of the news of Nicholas Hughes's death is almost unbearable. In his mother's poetry, he was saviour and life force - at his birth, she wrote, "this great bluish, glistening boy shot out onto the bed in a wave of tidal water that drenched all four of us to the skin, howling lustily", and he was for her the baby in the barn, "the one solid the spaces lean on". She loved her children, but not even loving them could save her, or, it now seems, him. Her son tried to survive her, escaping to Alaska, pursuing the wild fish through the icy rivers, but in the end he swam back up stream to the terrible birth and death place. Plath was heroic, in her struggles to create light and art from darkness, and so, I must and need to feel, was he. Margaret Drabble