Hatchery fish emerge – properly this time!

On the 7th March I posted a thread called “Hatchery fish emerge”. Of course that was completely the wrong terminology as emergence in a fish hatching context means when they lose their yolk sac and emerge from the gravel to feed. Surprised no-one pulled me up about that!

Yesterday Jimmy Woods called to say that a lot of the fish were “emerging” from the incubators into the tanks, ready for feeding. The system is designed to allow the fish to time their own emergence from the incubators. It is two months since the fish actually hatched, just shows how long the incubation period is for salmonids. I went up in the afternoon to have a look and take some photos.

Newly emerged fry in the feeding tank

Newly emerged fry in the feeding tank

A good hatchery manager is essentially a stockman; like any good stockman you have to observe your stock!

Keeping an close eye on the wee fish

Keeping a close eye on the wee fish

 

Close up of some of the alevins/fry

Close up of some of the alevins/fry. Some still had a little yolk sac which will disappear over the next few days.

Jimmy removed the plastic substrate from the incubators to encourage the remaining alevins to take the plunge.

Still a lot to emerge

Still a lot to emerge

The fish in the tanks are now being fed several times a day and if the warm weather continues they will soon develop. The temperature in the hatchery was 11oC yesterday, the same as in the lower mainstem. The River Dulnain stock were the first stripped and they appeared to be the most advanced yesterday. If the fish are emerging at 850′ altitude in the hatchery the same will be happening with the naturally spawned fish across much of the catchment.

Jimmy reckons the mortality in the egg phase was around 1% with little evidence of mortality in the incubators.

 

There are 10 comments for this article
  1. Charlie Herd at 3:11 pm

    I don’t want to labour my point but it is a fact that in general the chances of catching a fish on the Spey are not as good as on many other rivers in Scotland. I am just concerned that if we ‘ leave it to nature ‘ it could take a very long time for things to improve when there is evidence both here and abroad that giving nature a helping hand can work.

  2. Charlie Herd at 11:17 am

    Brian,
    The ASFB report highlights the fact that the Spey catch per rod is just about the lowest in the country and is about a third of the best. The west coast Carron achieved double the catch per rod of the Spey and once the fish started entering their river they were averaging one fish per rod per day, a rare event on any beat on the Spey!
    Abroad the Ranga and the Vosso have also proved that it is possible to regenerate a large smolt run and the Carron experience suggests that even on a very small budget stellar results can be achieved here in Scotland.
    Is it not possible that the negative attitude
    of the Board in this matter is being unduly influenced by the results of historical trials.? Since then major advances in technology and knowledge have produced results elsewhere which suggest that things have moved on. By ignoring these advances, are we not in danger of being left behind with a river that will continue to under perform and fail to achieve its full potential.? Is the salmon’s best defence not safety in numbers!?

    Charlie.

    • Brian Shaw Author at 9:08 am

      Charlie,

      Are you comparing the same thing here? Did you include all the potential fishing days on the Carron in your rod average calculations or was it just the days when conditions were right on a spate river? I won’t be a surprise to many to conclude that the rod average on a spate river during spate conditions can be very good.

      The best beats on the Spey average less than one fish per rod/day over the season but the fishing there is about as good as it gets in Scotland, so I’m not quite sure about the worth of your point. One way to increase the rod average would be to reduce the number of rods, do you want to make it more exclusive and difficult to access; hardly a good strategy in this day and age.

      Looking closer at your Spey rod catch analysis. Last year there were approximately 7500 fish caught, in a good year on the Spey there will be 10,000 fish caught, so the rod average last year was 75% of a good Spey year, the sort of year that would see smiles across Speyside. To compete with your “best” the Spey catch would need to be about 22,500 fish, a rod catch that has never been achieved. The Spey is what it is.

      I don’t think anyone is ignoring any advances, the Boards stocking policy has been progressive and is reviewed annually at least. I do agree about your point regarding safety in numbers though!

      Brian

      • GRAHAM SALISBURY SRG at 7:52 pm

        Hello Brian what do you believe has brought about the turn in fortunes of the Tay? Yours, GRAHAM SALISBURY SRG

        • Brian Shaw Author at 9:14 pm

          Hi Graham,

          First of all congratulations on your good catches at Craigellachie last week, I see from Malcolm’s report that you had some sport. Regarding the Tay surely it can only be the kelt reconditioning?
          Brian

        • GRAHAM SALISBURY SRG at 1:47 pm

          Brian, fishing is pretty much like anything else if you have the belief and then unrelenting determination you usually get the rewards! how are we getting on with the assessment of the PH levels of our nursery streams as I believe the shell fish method which has proven successful across the pond might have an important role to play on Speyside would you agree? KR GRAHAM SALISBURY SRG

          • Brian Shaw Author at 4:23 pm

            Graham,
            I don’t think that pH is considered to be a major issue on the Spey. Some of the streams draining the Cairngorms tend to be acidic but I suspect this is primarily a natural phenomena, with low buffering due to the granite geology. I haven’t found any evidence that pH itself is a limiting factor. The Allt a’Mharcaidh is an Acid Waters Monitoring Network site see http://awmn.defra.gov.uk/sites/site_02.php with a long history of fish and other data. There is a summary of the monitoring on the right hand side of the page. Salmon are generally present each year although fry numbers are more variable. The invertebrates show several mayfly species to be present, whereas in Ayrshire mayflies were found only very occasionally in the Carrick Lane, a major Loch Doon tributary draining the Galloway Hills. The water chemistry report appears to show an improvement in pH levels, although no readings below 5 were recorded so it should be okay for salmon egg hatching.
            The Knockando Burn is famously prone to acidic episodes but it still supports a good trout and mayfly population, with salmon fry present in good densities in the limited accessible part. This part of the catchment is considered to be more acidic than other areas but access is restricted into all the burns due to the steep terrain.
            When I did my electrofishing course with the Galloway Fisheries Trust I remember seeing what appeared to be crushed scallop shells on the forestry roads. The concept at the time was that the scallop shells would be constantly crushed and ground down by vehicle traffic on the forest roads and the leachate would eventually find its way in the burns. I don’t think there were ever any conclusive results. Prior to that the Galloway Trust had tried depositing shells directly into the burns but my understanding is that they oxidised rather than dissolved and there was no measurable change in water chemistry . I think current thinking on this side of the pond is that more direct liming provides a more effective solution with the Wye and Usk Foundation working in this area.
            One problem with the Galloway crushed shells trial was the odour from traces of meat left on the shells. Cleaned shells were eventually obtained but the source dried up when garden centres started to buy the shells for landscaping.
            I have contacted the organisation in the US to ask for their data regarding the impact of their technique but I can foresee difficulties if we propose trying to manipulate pH in the highly designated landscapes of the Cairngorms.
            Best regards
            Brian

          • Brian Shaw Author at 4:40 pm

            Graham,
            I received a reply from a fellow clansman a Mr Dwayne Shaw from Maine, regarding the clam shell work. They appear to have achieved very good results with a 1 point change in pH and higher densities of salmonids. I have referred the work to another Trust in Scotland where pH is a major issue and I will certainly bear this in mind if required on the Spey. Thank you for the suggestion, keep them coming.
            Brian

  3. Charlie Herd at 4:22 pm

    As far as I am aware most of the successful recovery or improvement programmes have involved the release of hatchery smolts. Have the Board ever considered this as an option and if not , why not?

    • Brian Shaw Author at 9:23 am

      Hi Charlie, as far as I am aware there have been very few examples of successful recovery programmes using hatchery smolts in Scotland, certainly none on the east coast of Scotland. There are a couple on-going programmes on the west coast where the published return rates for one river range from 0.01 to 0.25% (to the rod); on the other, the one I think you may be referring to, there are a number of assumptions made which would have a huge bearing on the stated egg deposition figures. Other programmes have been ditched not long after the first poor returns were apparent.
      I know that the Board have considered this option, probably more than once but on each occasion decisions on stocking were made based on perceived best value and least risk? Remember the Spey is a SAC for salmon so the views of national regulators have also to be considered.
      One of my favourite analogies is that stocking salmon is more akin to “stocking swallows than pheasants” (thank you JW). We are dealing with an animal here that has to do a circumnavigation of the ocean and all the challenges that presents.
      Looking at some of the catch returns in the ASFB/RAFTS annual report http://www.asfb.org.uk/wp-content/uploads/2013/03/2013-Annual-Review.pdf there are plenty of examples of rivers where there have been significant recoveries and not a stocked smolt in sight.
      Brian

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