The River Torridge Salmon Hatchery

For the last fifteen years I have been one of a small group of volunteers which has run a salmon hatchery beside the River Okement at Monkokehampton. It is extremely time-consuming but very rewarding and by the time you read this over 38,000 young salmon will have been stocked out into the headwaters of the Torridge and its main tributaries, the rivers Okement, Lew, and Walden, including about 3,000 into Mussel Brook above and below the bridges at Upcott and on the road to Black Torrington. The Torridge Fishery Association always wanted to set up its own hatchery. In 2007 a site was located beside the mill at Monkokehampton and we were able to purchase three holding tanks from the Environment Agency. It has very much been a learning curve, and we have been very indebted to Paul Carter, the EA Fishery Officer for North Devon, for his support and expertise. The annual process starts in early November with the capture of five hens and five cocks from the fish pass beside Monkokehampton weir. The adult fish are transported the short distance back to the hatchery in an oxygenated tank and are placed in the holding tanks after they have been weighed and measured. The hens weigh between 8lb and 12lb, while the cock fish tend to be much smaller - this year all the cock fish were between 4lb and 5lb. To provide oxygen, there has to be a regular flow of water through the tanks, which comes from the mill leat, and the fish have to be treated every other day to avoid the onset of a fungal growth on their heads. By early December, the hens are ready to be stripped of their eggs, which are fertilised by the milt of the cock fish. On average, each hen will provide about 8,000 eggs. The fertilised eggs (ova) are laid out in trays, and again, a regular flow of water is essential. After several weeks they will start to “eye up” - little black dots inside the egg. This is the first sign of life, and two or three weeks later they will start to hatch. Each baby salmon (at this stage called alevin) has a small yolk sac which provides food. They grow quickly, and as soon as the reserves in the yolk sac have been used up the little fish have to start feeding themselves. Still in the trays, they will come up to the surface looking for food, so they get the name “swim-up fry”. It is at this juncture, normally about mid-March, that they are ready to be stocked out. Batches of about 1,000 are transported by our band of volunteers to specially selected sites in the headwaters, where they will have the best chance of survival. The young salmon will spend two years in the river growing into salmon parr before swimming downstream into the Bristol Channel. About eight inches long, and very silvery, they are known at this stage of their life cycle as salmon smolt. These little fish will then begin their migration of several thousand miles to the feeding grounds off Greenland before returning as an adult salmon two years later, by which time some of them will weigh over 15lb. Salmon will always return to the river of their birth, so we know that, hopefully, at least a few of our “swim-up” fry will return to the Torridge as adults. Why do we go to all the trouble of running a hatchery? In the last fifty years the numbers of salmon returning to all the rivers in the British Isles has fallen dramatically, and nowhere is this more true than on our own river here in North Devon. Compared to fifty years ago, salmon numbers in the Torridge have declined by over 90%. If this decline is not halted, it will not be too long before the Torridge salmon will be something we can only talk about but never see. The changes in our climate are one of many reasons for the decline. Winters are getting warmer and wetter. For the last three months the river has continuously been bank high, often in flood, and most, if not all, of the salmon eggs deposited in the gravel will have been washed away. The few that were left would be covered in a layer of muddy silt, starving them of the oxygen so necessary for their survival. So at least our 38,000 “swim-up” fry have a head start. We have no proof that the hatchery is making a difference, but there are signs that the number of fish returning to spawn each year is marginally increasing. Surveys are showing encouraging numbers of salmon fry and parr, particularly in sections of the River Okement and River Lew. We like to think our efforts are helping.

Charles Inniss