Across the modern world, there’s an ever-growing movement challenging humanity to interact positively with nature’s processes and create change to benefit the planet for future generations.  

Behind this burgeoning global determination to act, is the understanding of a fine line between beneficial intervention and damaging interference and in one, picturesque part of Yorkshire, the fragile grayling is benefitting from such distinction.  

Once a year, the River Wharfe plays host to part of an Environment Agency project that works in harmony with nature’s balance and helps the ‘Lady of The Stream’ to increase its number. It’s here, that Grayling Day; has operated on the basis of environmental positivity and old-fashioned collaboration for the last decade. 

In short, this is how it works:

The resultant fry are then reared in perfect growing conditions, until ready for strategic release into waters that have been specifically identified for having suitable conditions.  

The exercise at Calverton is run in accordance with the EA’s National Trout and Grayling Strategy – a programme that runs about as far from the phrase ‘ad-hoc’ as any plan could. The strategy identifies four distinct genetic strains or ‘families’ within which the grayling population sits. It also dictates a geographical river footprint within which the identified strains of newborn fry can – and more specifically by default – cannot be introduced. Such is the delicacy of the grayling’s gene pool, indiscriminate introduction into England’s waterways just will not work.  

“The Trout & Grayling Strategy dictates that you have to stock grayling from the right genetic strain,” says Calverton Fish Farm Technical Officer, Richard Pitman. “The fish that come out of the River Wharfe will go back into the Wharfe, and into other areas across the north and north east that are approved for their specific make-up. They could be stocked as far up as Durham or down to the Ripon area.”  

Calverton’s Grayling programme also includes adult collection exercises with identical parameters in the midlands and the south which cover all the Environment Agency stocking requirements. Overall, it provides a massive influx of grayling into suitable English waters, and the practical evidence confirms the process is making a difference. 

“We released 89,000 grayling fry across the country last year as part of the ongoing stocking plan” says Richard. “We’re now seeing fish in areas they were not showing in before, so we know it’s working. It’s important to remember that the grayling has a natural place in the eco-system so we’re looking after the environment and not just the anglers. Overall, we want the numbers to be increasing and to be self-sustainable.” 

Once caught, the adult, donor fish stay at Calverton for 8 to 10 days. The eggs incubate for 25 days, and the fry are grown on before being put into their allocated stretch of river about 6/8 weeks after hatch. At this point, they’re approximately 5cm long, but before that important moment, Calverton provides an environment at the farm that sharpens their natural survival instincts. 

“The fish in the river have got constant, natural food coming past them all the time,” says Richard. “So the fry are grown in flowing water from the moment they hatch, which means there’s no lack of ability to keep up with flowing conditions in the wild. We also provide as much natural food as possible for them during their stay and put artificial structures into the troughs so they know how to interact with natural cover. The first food the larvae receive is Artemia. This live food is a small swimming shrimp the larvae must actively chase and this triggers their inbuilt snap responses and hunting instincts. It is also full of natural enzymes which give the newly hatched larvae a boost and helps to kick start their gut. They’ll also have daphnia and bloodworm amongst other things, so when release time comes, they don’t go out as naive fish. We look at the fish husbandry and re-stocking from a fish’s point of view rather than it just being a numbers game. Our aim is to make the fry fit for purpose before release.” 

It’s not surprising that the anglers who work with Calverton to catch the donor females are all willing volunteers. Grayling Day is a powerful eco-project that has its starting point in the fundamental enjoyment of a day’s fishing. Albeit with some associated pressure! 

“It’s a good social day out and we enjoy understanding what goes on,” says Leeds & District ASA Vice President & Fisheries Liaison Officer, Dave Rushton. “There’s a sense of pride when your fish are taken away as part of the process and the anglers feel they’ve contributed towards something positive. There’s a genuine ‘feel good’ factor but it’s also a challenge because when somebody asks you to catch them ten grayling you need a real sense of focus! You fish hard, try different swims and tactics and even if you catch, you can’t guarantee it’s a female! But when you see the van with the tanks drive down the field to pick up the fish you’ve successfully caught, you do get a good feeling that you’ve achieved something.” 

Wetherby & District A.C. Match Secretary, Nick Sutton agrees, especially as planning the catching session is critical to the whole operation. “There’s always a small window of opportunity in late February or early March when we’ve waited for the river to drop,” says Nick. “We could all go on a flooded river but the E.A. have to set off based on what we’re likely to catch so it’s difficult getting it right and it’s always a bonus when it happens well. This year it did. Anything we can do to protect the fish and help the breeding, we’ll do happily.” 

So, it’s no surprise that the unique fragility of the species is considered at all stages, and when discussing this aspect, Nick Sutton is happy to pass on a tip that will stand all grayling hunters in good stead for the future.

From start to finish, it appears that Grayling Day and its offspring are in very good hands.