Cree Hatchery and Trust Visit 4th Feb. 2024

Visit Report

The purpose of this visit was to better understand the work that has been undertaken by the Cree Hatchery & Trust in relation to their approach, processes and successes in supplementing local Atlantic Salmon numbers within their catchment.

 Established in 2010 by a group of conscientious members of the local angling club the River Cree Hatchery and Trust is a charity-based organisation relying almost entirely upon grants and donations. The Cree Hatchery and Trust has only one salaried employee – hatchery manager Murdo Crosbie. The Trust has been and is supported by the local DSFB.

The Cree Hatchery and Trust was established with the main aims for establishing a stocking management plan and capability due to the following threats:

·        Poor Water Quality (Ph levels 3.7-4.0 regularly measured)

·        Degraded habitat

·        Increasing large spate events resulting in Redd washout

·        Siltation

·        Predation

The overall aims of the Cree Hatchery and Trust are as follows:

·        Stock out areas of the catchment with low or no populations of wild salmon juveniles

·        Improve degraded habitat

·        Predation control

·        Education – local community engagement and in particular you people

In terms of results then I believe that Hatchery Manager Murdo Crosbie would agree that even with this investment and effort the Cree fishery rather than seeing a rapid increase in salmon population is in fact ‘holding steady’ based upon the last ten or so years of rod catch returns compared to neighbouring rivers and catchements.

The Hatchery Process Overview

Currently a total of approximately 66 male and female brood stock fish are collected from the catchment at the end of October each season from electro fishing activities across the catchment. (Marine Scotland only provide licence for 2% of rod catches to be captured as brood stock). There are specific measures and controls in place throughout the hatchery process to ensure that brood stock, their fertilised eggs, alevin and subsequent released fry are returned to their original geographic locations or stems and altitude within the catchment. By maintaining this integrity then this reduces the potential risks associated with changing or interfering with the DNA or genetics of the local original salmon populations.

Around 200,00 eggs are harvested each year which results in around 180,000 mouth fed fry stocked out of which 20,000 are fin clipped Autumn released fry.

Once female brood stock is stripped the eggs are ‘dried’ before then being fertilised within a short period of time. It is understood that this increases the fertilisation yield.

One excerpt describing this harvesting process is “Catching broodstock up the Minnoch this morning and then stripping 3 hen fish in the hatchery this afternoon giving approximately 14,000 eggs. I began by stripping each hen fish of her eggs into individual buckets, the contents of these are then equally shared into a further 3 buckets, giving us 3 buckets containing a mix of eggs from each of the hen fish. We then add the milt from 1 cock fish per bucket that then gives 9 pairings from the 3 hens. The reasoning behind this is to give a good spread of genetics.”

Each stage of the hatchery process utilises gravity fed water which is abstracted from the local burn adjacent to the hatchery and it’s water is continually cycled through each stage of rearing.

The fertilised eggs are then carefully placed in individual incubation trays based upon specific catchment original geographical location for onward development and monitoring. Incubation begins in November and extends until March or April.

Each stage of the hatchery process utilises gravity fed water which is abstracted from the local burn adjacent to the hatchery and it’s water is continually cycled through each stage of rearing.

The fertilised eggs are then carefully placed in individual incubation trays based upon specific catchment original geographical location for onward development and monitoring. Incubation begins in November and extends until March or April.

The speed at which these Alevin develop into fry is dependent upon natural air and water temperatures. Once fully developed the fry exit the nursery tank by swimming towards the light of the transparent exit pipe and into nursery barrels for ongoing fry development and feeding.

Rearing and eventual release of fry can extend throughout the summer until September each year as fry are routinely segregated and removed for release based upon size. All fry continue to be separated and stored according to original brood stock location.

Fry are routinely selected for release based upon size and this process usually begins in April each year. Last year (2023) some 180,000 fry were reared and released. Prior to release at the selected (original) site each of the 20k ‘Autumn’ fry for release are manually fin clipped. This is a time-consuming, labour-intensive process but considered key since it allows subsequent identification of hatchery reared fish.

With the use of volunteers, the hatchery transports and releases ‘batches’ of fry to various sites across the catchment including the main river stem and tributary burns throughout the summer and Autumn depending upon conditions and maturity of the fry. 

Appendix 1.

The overall aim of a Fishery Management Plan is to produce a long term management strategy, incorporating current fishery issues and management. For a river catchment this would include the river, tributaries and still waters.  Plans may also include aims and objectives, a description of the fishery including an assessment of current stocks, apparent limiting factors within the fishery and a monitoring plan and review process.

A vital element within the plan is the collection of basic information about the catchment or sub catchment, including relevant historical and recent data relating to the catchment. In this way any gaps in knowledge of the system will be identified. It is essential to ensure that FMPs are working documents that can be used by stakeholders, agencies and other interested parties. GFT has produced FMPs over the years but with various success. Many lessons have been learned.

In 2023, Fisheries Management Scotland, Crown Estates and Marine Scotland started an initiative to support the production of evidence-based Fisheries Management Plans for Trusts / DSFBs to assist in the management of salmon and seatrout in each District.  These on-line plans are presented as story maps through ArcGIS.  The completed plans should be publicly available at some point in 2023.

Are hatcheries the answer?
There is much controversy surrounding the use of hatcheries in fishery management, especially regarding bad practice. Examples of this include stocking fish into areas which already contain healthy populations of wild fish or stocking fish from one catchment or sub-catchment into another. Many studies are now showing that fish returns from hatchery programmes are very low and in many cases, it would be better to leave the fish to spawn naturally.

Hatchery programmes do not directly increase rod catches as hatchery produced offspring will not produce significantly greater return rates than if the adult fish were allowed to spawn naturally. In fact, studies have shown that survival rates may be severely diminished, particularly smolt survival at sea. In 2011, RAFTS and the Spey District Salmon Fishery Board published some interesting results of a detailed genetic-based study that showed that from annual stocking of well over 1,000,000 eyed ova and fry, this stocking only produced 50 salmon to the anglers out of a total of over 8000 caught each year. It also has to be assumed that all the broodstock collected out of the river would naturally have produced many fish if they had been allowed to spawn naturally.

Hatcheries can, however, be a useful tool in some types of fisheries management. In situations where the natural population has become critically low, man may step in to prevent in-breeding within the remaining population or re-establish viable populations in areas where populations have become extinct or very low. This is the basis of all of the stocking which GFT now undertakes. We stock watercourses with suitable habitat where acidification in the past has devastated the natural fish population through poor egg survival but where water quality has now improved to a level that introduced fish can survival.

GFT has developed a code of best practice to counteract problems associated with local hatchery programmes. This considers issues such as biosecurity, genetics, stocking with native stock and the stocking at different stages of development (e.g. eyed ova versus fry). Broodstock fish are collected each winter prior to spawning using a range of methods including electrofishing, rod and line, netting and fish traps. Broodstock are separated into catchment and sub-catchment categories so that their progeny retain their natal genetic integrity and they are stocked back into their natal sub-catchment.