Wednesday, July 9, 2008

Week 25

Week 25

Fishing is now starting to pick up again, the fishes’ appetite re-emerging post Mayfly. The fishing is not easy, any fish caught in the day between showers on olive patterns or a Daddy Long Legs, fish in the evening to Sedge patterns. Numbers of sedges are really building up and by eight o’clock there are literally thousands of them skittering around just above the water, we are also starting to see some of the huge sedges that appear late in the day during the summer months. Fish often slash at these at dark, and if your eyes are up to it, it is well worth staying into the last few minutes of daylight as the bigger fish often have a go at these dusk dwelling flies. Quite a few fish have been caught this week, several of them fish that were stocked in previous years, big fish and in superb condition; they know what it is about and take some catching. I have also stocked the river this week, and in previous years have been busy this week with several fish deliveries to other rivers and beats. Unfortunately this year this has not been possible, and is unlikely to be possible in years to come. After consultation and research, the Government are phasing in the implementation of the “National Trout and Grayling Strategy” over the next seven years. This strategy has been much talked about over the last few years and its main aim is to protect the wild stocks of Brown Trout and Grayling in all of UK’s rivers. Heavily influenced by the Wild Trout Society, it means that any river with a genetically identifiable population of wild Brown Trout must only be stocked with sterile fish – Triploids, or Diploid fish rose under a suitable rearing regime. What is considered a suitable rearing regime we wait to see? We currently raise our own fish from our own Brood Stock; the progeny are male and female and are fertile, as nature intended them to be. While we will no longer be able to supply fisheries on other river systems with these fish we hope to be able to continue stocking them into our river. It means a scaling down of our already small fish production, and a loss in revenue that will have to be passed onto the angler, or increasing pressure on the river by selling more rods.
While I can see the benefit of stocking Triploids in some rivers and lakes, I do not agree with the enforced stocking of them into this river system. Triploids are produce by interfering with the cell development of a newly fertilised Trout egg when they are around twenty minutes old. The eggs are subjected to either a short period in water at a significantly higher temperature, or a short period in a pressure vessel at an incredibly high pressure. The technique was first developed to enable Put and Take Trout fisheries to provide better fishing through the winter, previously they had been able to stock with rainbow Trout that do not breed in this country, although the females still developed eggs and the males milt. While in spawning condition their sporting value was diminished going off the feed and losing condition. Initially there was a move to stocking all female fish, a technique developed for the table market where there was a problem with cock fish having poor flesh quality for several months of the year. A normal batch of fish are fed a diet containing methyl testosterone for several months, all the fish develop male characteristics including the production of milt. The fish that were initially female remain genetically female but can produce milt, these fish are then used to fertilise normal eggs the result of which are all female progeny.
Both of these techniques have been in wide use over the past thirty to forty years. There hasn’t been a male trout sold in a supermarket for many years, something that the GM food lobby missed out on.
Today the ideal fish for stocking into a river containing Wild Brown Trout is deemed by the Government agency to be an all female Triploid Brown Trout. A fish that will feed throughout the year will not spawn and is capable of out competing most other fish in the river. Some stretches like them because they are said to be relatively easy to catch, there are also many reports of how they like to shoal. Many American rivers love them to bits, others are not so sure.
With today’s powerful move towards the ethical production of foodstuff, the label of Frankenstein science could quite easily be thrown at the production of Triploids and All Female Trout.
At the moment we rear and stock male and female Brown Trout, some at a takeable size some undersize to grow up in the river. This is a practice that has gone on in The Test Valley for nearly two hundred years with fish introduced from all parts of the country; it is not possible to identify the initial wild “Test” stock. The Wild Trout Society and the Government Agency state that these fish have interbred with wild populations; because they have been farm reared they have not been subject to the rigours of Natural Selection and could in some cases be weakening the strength of the spawning fish stock in the river. To get round this one I would suggest that instead of stocking Triploids that will out compete a normal fish for food at a critical time when it is looking to recover from spawning, beats are encouraged to stock with greater numbers of smaller undersize fish that are left to grow up in the river and would be subject to a certain amount of natural selection. Support the Keepers and Owners on Predator and Fishery Management issues; let the Keeper “keep” the river in a strategy that mirrors the much-lauded Salmon stocking policies for many rivers. The fish may not be the genetically wild stock, but after two years in the river they look wild and are more likely to be successful spawners.
The National Trout and Grayling Strategy is flawed, the biggest problem being that is a National one and not a regional one. Management practices for rivers in one part of the country will not necessarily work in another. Of course this will be dismissed as another rant by a keeper on a river in decline where they cut the grass too short and the fish are too big. I would point out that many of the practices claimed and practiced by some of these conservation groups were developed and used on this river a long time before they got hold of them. There is a depth of knowledge passed on from generation to generation about how to keep Mr & Mrs Trout Happy that should not be discounted, and would urge many of them to take on board the advice in the response to the strategy by The Test and Itchen association.

3 comments:

John Aplin said...

Nice to see a fellow river keepers blog cheers John http://riverworksblog.blogspot.com/

Anonymous said...

Please stop falling off roofs, trees, etc - we need you next season!
Christopher Normand

Test Valley River Keeper said...

Thanks for your concern Mr Normand, but if it keeps raining like this you may find us all on the roof on the opening day of the season