This taxon is currently regarded as valid for global Red List purposes, but was treated as a subpopulation of the Arctic charr, Salvelinus alpinus (Linnaeus 1758), for the most recent national assessment (Nunn et al. 2023).

The taxonomic status of Salvelinus subpopulations inhabiting the British Isles has not been definitively resolved since a series of endemic species were described between the mid-19^th and early 20^th centuries (Adams & Maitland 2007).

In the United Kingdom and Ireland, all of these taxa are treated as junior synonyms of the Arctic Charr, the name of which has been routinely applied to a widespread complex of polymorphic charr populations occurring throughout the Holarctic region (Jonsson & Jonsson 2001). However, there remains considerable uncertainty regarding the systematics of the genus across the majority of this range (Reist et al. 2013; Taylor 2016; Whiteley et al. 2019).

Members of this "Arctic Charr complex" exhibit bewildering subpopulation-scale ecological and morphological variability. When such divergence occurs within a single lake system, the different sympatric forms are often referred to as “morphs”, “morphotypes”, "ecomorphs" or "ecotypes" (Snorrason et al. 1994; Adams et al. 1998; Knudsen et al. 2006; Klemetsen 2010; Muir et al. 2016).

Some of these subpopulations and sympatric forms have over time been described as nominal species, including at least 15 from North America, around 30 from Europe and 12 from Siberia and the Far East. However, these taxa encompass only a small fraction of charr distribution and diversity, and there exist significant differences in opinion regarding which of them should be considered valid (Savvaitova 1995; Adams & Maitland 2007; Kottelat & Freyhof 2007; Klemetsen 2010; Whiteley et al. 2019).

With the above in mind, there is an emerging consensus that the striking genetic and phenotypic diversity exhibited by members of this genus cannot be adequately represented by a single accepted taxonomic system (Whiteley et al. 2019).

The Red List currently follows the nomenclature provided by Fricke et al. (2024), albeit a species-oriented conservation management approach is unlikely to prove appropriate for members of this genus (Barthelemy et al. 2023; also see 'Conservation').

Global and European regional assessment: Extinct (EX)
EU 27 regional assessment: Not Recorded

The Orkney Charr was last recorded in the wild during 1912, and no ex situ subpopulations exist. Therefore, this species is assessed as Extinct.

This species was described from Heldale Water on the island of Hoy in the Orkney archipelago, northeastern Scotland, with anecdotal evidence suggesting that it may also have been present in adjacent Hoglinns Water.

The small size of these lakes precludes their accurate depiction on the range map accompanying this assessment.

A putatively conspecific subpopulation inhabits Loch Mealt on the Isle of Skye in the Hebrides archipelago, western Scotland. However, its identity has never been explicitly confirmed and it is not considered for the purposes of this assessment.

Farmed charr which may have originated from mainland Scotland were apparently introduced to Heldale Water in 2002, but it is unclear if a non-native subpopulation subsequently became established.

This species was last reported during 1912 and has presumably been extinct since around that time, with no individuals recorded during surveys carried out since the 1950s.

Heldale Water is an oligotrophic dammed lake with a current maximum depth of 15 metres.

The smaller Hoglinns Water has a maximum depth of 17 metres and drains to Heldale Water via a small stream.

Both lakes were formed after the last glacial period.

Engineering works during the late 19^th century may have disturbed tributary streams into which this species migrated to spawn.

Heldale Water was stocked with non-native Brown Trout (Salmo trutta) during the early 20^th century, which may have contributed to the Orkney Charr's extinction through predation and/or resource competition.

This species was not used or traded.

This species is not currently recognised by the relevant authorities in Scotland or the United Kingdom, where it is treated as a subpopulation of the Arctic Charr (Salvelinus alpinus). The taxonomy of Eurasian charrs is in need of review (see 'Taxonomic Notes'), and it has been widely recommended that their conservation management must be considered independent of their systematic classification. Each subpopulation should therefore be assessed individually, taking into account its evolutionary and genetic significance coupled with the ongoing population trend and threats to result in a priority ranking permitting the effective allocation of conservation resources through the development of site-specific, catchment-scale management plans. Sympatric morphological forms should also be managed separately, depending on their respective habitat preferences, diets and life histories. The abundance trends of many subpopulations remain unknown, and their individual assessments should ideally form the basis of future research efforts in order to ensure appropriate prioritisation. In practice, such efforts should ideally be coordinated at local, national or regional scales.