In 2008, following review, a small salmon hatchery was implemented on the Dunbeath Water. Motivation for investing in a salmon hatchery was threefold: (i) to stabilise and increase the salmon population in the Dunbeath Water; (ii) to improve our understanding of Dunbeath salmon and the river’s wider ecology; and (iii) to improve public engagement and understanding of wild Atlantic salmon. Additional to these important drivers, the hatchery was an excellent opportunity to make use of the old Dunbeath Corn Mill, which is sited next to the lower stretches of the river. The Mill traditionally drew water from the Dunbeath, so it was possible to continue a reliable and high-quality supply of local river water for the hatchery, resorting to internal recirculation when levels and flow were low.

The hatchery’s key role was to allow a small subset of Dunbeath salmon to be reared within the protected environment of the hatchery, thereby insuring against an increasingly severe set of complex pressures facing wild salmon in the river and sea. Although the hatchery environment is necessarily benign by comparison with selection from the wild, and there is evidence that hatchery-reared fish may not perform as well as wild-reared fish following restocking, hatcheries allow the balance between selective improvement and mortality to be shifted in favour of survival. Hatcheries can therefore allow some insurance when wild selection is especially severe. There was evidence that severe selection and mortality had been operating at some stage on Dunbeath salmon in the recent past, with catch records in some years dropping into single figures (e.g. just 6 and 7 fish in 2000 and 2003, respectively). The proprietor and river management team therefore took responsibility to improve conservation management of Dunbeath salmon through various measures, including a carefully-managed hatchery restocking program.

The intention of the hatchery program was not to swamp the river with salmon for the benefit of anglers, potentially creating density-dependent issues within juvenile habitats, but to provide insurance and protection against the increasing threat of exceptional and unpredictable weather, disease, predation and biotic invasion in the river, as well as the uncontrollable pressures that face adult salmon at sea. In droughts, for example, fish cannot enter the river so that lower numbers spawn and, in floods, the redds can be washed out and a large proportion of that year’s reproduction lost. In addition to more responsible management of the river and its salmon, the hatchery was also intended to serve two further important ambitions: (a) as a facility for furthering our understanding of salmon biology and the wider ecology of Dunbeath Water, including the monitoring of health and disease, and (b) as a resource to promote education and engagement about wild Atlantic salmon conservation and ecology, especially its role as a keystone species, with particular relevance to Northern Scotland.

The Dunbeath Water has been historically stocked with fed fry, but the Dunbeath Management Plan wished to implement its own hatchery so that direct control could be exerted over a number of restocking variables, including: (a) the source and genetic background of any hatchery broodstock from within the Dunbeath system, (b) the number of broodstock, (c) their husbandry, (d) the method of artificial fertilisation and parentage, (e) the numbers of offspring re-stocked, (f) their respective life stages, and precisely (g) where and (h) when the juveniles were restocked.

The hatchery has now been operating since 2008, so we report on its progress across four general areas: 1) hatchery activity, 2) salmon catch statistics, 3) monitoring, management and research, and 4) education and engagement.


Dunbeath salmon hatchery increased its activities from 2008, and in 2011 became fully operational. Since 2011, the hatchery has been operating according to the Dunbeath Water Management Plan, aiming to strip and rear eggs from 5% of the adult hens in the river, which local expertise has given their best estimate to be 10 hens per annum. Broodstock are caught at the end of the fishing season using permitted methods, and then maintained in mixed-sex 5,000 litre tanks until ripe. Any signs of fungus or disease have been managed using saltwater wash. Since the start of the hatchery, only 5-10% of adult broodstock have been lost to disease, and all the survivors have been successfully stripped and returned to the river.

Only locally-adapted Dunbeath fish are used in the hatchery, though there has been a focus on trying to access gametes from multi-sea-winter spring-running fish where and when possible. Ovulating hens are stripped (following light anaesthesia), and fertilised simultaneously by milt from two to three cocks, to mimic the natural salmon mating pattern and allow any post-mating selection to operate. All adult broodstock have been allowed to fully recover after stripping, and then released to a known holding pool in the river within 1km of the estuary in the hope of some mending. Eggs have been fertilised ‘dry’ according to standard salmon hatchery protocols (see report section below comparing dry versus wet success rates), and raised in hatchery trays fed by river water at natural temperatures. Any dead eggs have been picked on a weekly basis. After hatch in March, alevins are transferred to 1m diameter tanks, stocking at 3,000 fish per tank, to get them through the difficult stage onto active feeding. Once successfully through this key stage, fry are moved to 2m diameter tanks with shaded covers and plastic refugia.

Each year, the 10 stripped hens have typically produced ~50,000 eggs for restocking. The hatchery has achieved good success rates through fertilisation and rearing: ~95% of stripped eggs are fertile and successfully hatch. If retaining hatchlings instead of restocking, 10-20% of yolked alevins are lost in the transition to feeding at 6 weeks of age (an especially vulnerable stage). After the transition to feeding, very few fry and parr are lost (1-5%).

The restocking strategy is deliberately flexible, and designed to react to areas of the river where adult spawning or juvenile surveys suggest reduced numbers, and/or habitat has a high carrying capacity. The core approach has been to return unfed fry to prime juvenile habitat, especially areas where previous spawning surveys have revealed lower numbers of adults than expected from local knowledge. Electric fishing surveys of these sites that have been stocked show healthy numbers of fry and parr present. Fry are returned to the river in April, over a three to four week period (commensurate with when different groups hatched). Restocking takes place using genetically mixed families at any one site, avoiding the creation of genetic structuring which could lead to future inbreeding. Fry are carefully introduced along a suitable stretch of juvenile habitat, spreading out the introduction at a typical rate of 2000 fish per km of stream section, and avoiding extreme weather or flow conditions. In addition to unfed fry, some early- and late-stage parr have also been grown on in the hatchery and restocked, some of which have been fin-clipped to assess hatchery contribution (see below).


We expect any hatchery contribution to adult returning salmon to have begun from 2012. The average annual catch of salmon in the Dunbeath Water between 2000 and 2011 was 56. Although this number can be influenced by a number of factors in addition to the size of the population of adult salmon running the river, there were years when records show only 6 and 7 salmon were caught, in 2000 and 2003 respectively. These figures were a major concern, presenting risks of Allee effects, and therefore motivating more proactive and responsible management, to include the hatchery. Since 2012, annual catches have increased more than two-fold to an average of 139 (Figure 1).

The contribution of the hatchery to this improvement is difficult to confirm exactly, but two pieces of evidence indicate that the management plan and hatchery have played significant roles:

(i) Despite low flow, difficult angling conditions, and some evidence of Saprolegnia fungus on adults in the holding pools, the minimum catch figure since 2012 has been 58 (in 2013), a ten-fold improvement on minima recorded between 2000 and 2011.

(ii) Between 2012 and 2016, 1500 of the largest grown-on parr from the hatchery have been released at smolting time (late April- early May) into the Dunbeath. These released smolts were all marked by adipose fin-clipping. To our knowledge there is no other current / recent fin-clip marking in river systems around Dunbeath’s northeast coastline. Since 2014, 22 salmon have now been recorded successfully returning to the Dunbeath that were marked with fin clips, and therefore raised from the hatchery. The supplementary stocking program is evidently making a positive contribution to the population of returning adult salmon, with the number of fin-clipped salmon recorded in the Dunbeath across the following years: 2014 - 3;  2015 - 7;  2016 - 10;  2017 (to July) - 2.

We cannot calculate the exact contribution of the hatchery to the number of returning adults because: i) the fin-clipped parr were only a small proportion of the total fish released back from the hatchery, ii) we do not have exact numbers of fin-clipped returning fish (because not all anglers report them, so the numbers will be under-reported), iii) we do not know the relative success of different juvenile stages, and iv) we do not know the total number of salmon in the river. However, the number of fin clipped fish recorded between 2014 and 2016 was 5.5% of the total salmon caught returning to the Dunbeath (20 clipped of 386 adult fish), indicating that at least the large parr / smolting fish stocked from the hatchery have made an equivalent contribution to reproduction by the wild spawners, if the number of broodstock used in the hatchery is indeed 5% of the wild spawning population.

Of particular note, in May 2017, two large, fresh-run spring fish (estimated 7.5 and 9.5 lbs) were recaptured that had been fin clipped, and therefore derived from the hatchery (Figure 2). The Management Plan has specifically targeted the re-establishment of the traditional run of larger spring fish, so this recapture was a very encouraging start. Scale readings from the larger of these two fish by Marine Scotland reveal the salmon to have spent two years at sea before return, and therefore most likely stocked from the hatchery into the Dunbeath in May 2015.

Figure 2.  Spring salmon caught in May 2017 on the Dunbeath Water and marked without adipose fin as being reared in the hatchery and released as a smolt in 2015.


The Dunbeath Water management team and members of the Angling Club have been active in monitoring and managing the river at a number of levels beyond the hatchery. Overall fisheries’ management of the county of Caithness is guided by the Caithness District Salmon Fishery Board, a statutory body created by Parliament in the 1860s. This board, together with the Northern District Salmon Fishery Board, has taken the initiative of forming a charitable trust called the Flow Country Rivers Trust, the purpose of which is to advance for the public benefit the conservation of all fish species within the Flow Country catchment together with the flora and fauna proximate to the rivers and stillwaters. The Dunbeath Water Management Team work closely with the Flow Country Rivers Trust. The current Dunbeath Management Team consists of: S.W.M. Threipland (Owner), Professor Matthew Gage (University of East Anglia), J.R. Fleming (Chair, Flow Country Fisheries Trust), Henry Young (Head Water Bailiff). The group meets formally twice a year, informally on numerous occasions, and is in active communication with members of the Dunbeath Angling Club.

Each year, annual rod catch statistics are collated and the fishing club rules and regulations are reviewed. The river bailiff monitors the river full time, and poaching incidents have been minimised and policed. Croys and banks have been maintained, and bankside vegetation has been managed to prevent overgrowing and maintain shading and protection. The Dunbeath Water has two traditional hatches on Loch Dubh and Loch Braec, which have been used to allow small improvements in water flow during times of drought.

Unusual catches, such as potential farm fish, are required to be reported to the bailiff, and the club is watchful for other invasives such as Pacific salmon species; neither of these have yet to be seen in the Dunbeath, despite Pink salmon (a Pacific species) being caught in July 2017 from the Helmsdale and Thurso either side. Scale readings are submitted for unusual fish, such as the hatchery-derived springer in 2017. Disease outbreaks are reported and monitored, particularly extreme louse load, Saprolegnia and Gyrodactylus. The only significant disease problem recorded since 2012 is evidence of Saprolegnia in the river and hatchery in 2016 and 2017, which is a freshwater fungus that thrives in colder conditions. Saprolegnia is known from a number of Scottish rivers, and there is limited evidence so far that it is a new disease, or that it can be managed, but we remain vigilant.

Annual juvenile surveys have been conducted at historical sites along the Dunbeath by independent SFCC-qualified teams since 2011. Five principal sites of 10m² are surveyed in the main stem of the river. Additional sites on tributaries have been snap-surveyed with an electro-fishing backpack and a catch net to gain an idea of where juveniles thrive or otherwise. The high ground sites revealed low numbers of salmon, but reasonable trout populations, as expected. The main sites showed average to very high abundance of salmon fry and parr, and these have been in good condition. The numbers compare very favourably with those in both local and other Scottish salmon rivers, and additional independent surveys by the Caithness Board. In general, the Dunbeath supports average to very high abundance of fry and parr in good condition, with densities of 0.3 to 1.4 fry and 0.3 to 0.4 parr per m2. As a result of these initiatives we have established important survey data for fish in the Dunbeath Water.

The Dunbeath Water management team actively engages with SEPA to enable ongoing hydrological monitoring, and the data are passed back for inspection and storage. During the breeding season, traditional redds are monitored for presence of spawning adults. A spring dipper survey of the entire river has been conducted, indicating nesting only in the lower reaches. Each year, all broodstock used in the hatchery restocking program have a DNA sample taken and stored, so we have initiated a Dunbeath Water salmon genebank, which could be important for future assessments of genetic change, and/or more refined measures of the contribution that the hatchery makes to the wild population.

The river and hatchery has also enabled a number of specific research projects. A genetic survey of 49 hatchery-produced Dunbeath parr confirmed additional findings from Norway that 10-20% of fish produced through artificial breeding can be triploid. Triploid fish have three sets of chromosomes which, in Atlantic salmon, makes them sensitive to stress and reproductively sterile, and therefore unwanted as part of any hatchery conservation program. The hatchery has enabled experimental tests of whether triploidy might be induced under ‘dry’ fertilisation conditions, when fertilisation of the egg can take place in ovarian fluid, and before water-activated initiation of the fast-block to polyspermy. Using split-clutch designs, and comparing egg batches fertilised ‘dry’ versus ‘wet’, no increased level of triploidy was found under dry conditions, eliminating the polyspermy hypothesis for unintentional triploidy. We were also able to show that fertilisation success, hatch rate and juvenile survival was no different between dry and wet artificial fertilisation methods (Figure 3). Moreover, additional genetic testing revealed that the third set of chromosomes in triploid salmon had invariably come from the mother. Although we have yet to prove what causes unintentional triploidy, and then eliminated it from hatchery production, collaborative research with the Dunbeath Hatchery has allowed an important part of the puzzle to be solved, and further tests are now under way.

Figure 3.  By tracking eggs from fertilisation through to hatch and alevin development, research at Dunbeath Hatchery has shown that ‘dry’ fertilisation methods are as effective as ‘wet’ for encouraging egg development and juvenile development, with no difference in triploidy incidence.

Another specific research test has been conducted with the hatchery: exploring whether greater carrying capacities exist for juvenile salmon in prime habitat on the river. By using the results of past electric fishing surveys, and before targeted restocking had been implemented, survey sites were deliberately stocked to a high density (Figure 4), in order to determine whether a greater juvenile carrying capacity exists. Future surveys will examine whether juvenile densities have increased, and therefore whether higher juvenile carrying capacity can exist in the river which restocking could take advantage of.

Figure 4.  Experimental ‘over-stocking’ to determine whether greater juvenile carrying capacities exist at traditional survey sites on the Dunbeath.

Figure 1.  Annual rod catch of salmon on the Dunbeath Water from 1997 to 2019. Figures combine grilse and salmon. Blue arrow indicates start of Dunbeath Hatchery. Red arrow indicates start of possible hatchery contribution to catch.



2018 was a very difficult year with minimum water throughout the season. The rains came in October by which time it is thought that many of our fish had - in desperation - headed up the Helmsdale River.

Some 1250 were counted over their fish counter in a night! However late spawning activity was seen by our stalkers on the Redds in mid to late October. So ……..!

Catch Record - 103 Fish for the Season.

Dunbeath Water was returned to Grade 1 for 2019 having suffered Scottish Marine's moment of madness by degrading us to Grade 3 for 2018 - although all scientific surveys and electro fishing data collected show our river to be highly sustainable and very healthy in terms of Parr, Fry , Smolts and water quality.




2019 - A strange year, plenty of water and fish seen in the river from April / May onwards  but with all the anglers skills they just didn’t seem to want to take the fly until later in the season. When one was caught early on it seemed to be just in the lip and more by chance than a positive grab at the fly. There were early signs of infection that caused so much concern on many Northern rivers but by June this seemed to have disappeared. Overall the river seemed in good heart.