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 and Maitland 2007).

In the United Kingdom and Ireland, all of these taxa are treated as junior synonyms of the congeneric Arctic Charr, Salvelinus alpinus (Linnaeus 1758), the name of which has been routinely applied to a widespread complex of polymorphic charr populations occurring throughout the Holarctic region (Jonsson and 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 and Maitland 2007, Kottelat and 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: Vulnerable (VU)
EU 27 regional assessment: Not Recorded

Younger's Charr has an extremely restricted range (extent of occurrence (EOO) c. 9 km², area of occupancy (AOO) c. 4 km²), which meets the thresholds for the Critically Endangered category under Criterion B1 (EOO < 100 km²) and Criterion B2 (AOO < 10 km²). It is restricted to one location, but there is no clear evidence of continuing decline or extreme fluctuations, hence it does not qualify for a threatened category under Criterion B.

There is no demonstrated population size reduction that would approach the threshold for Vulnerable under Criterion A (≥ 30% over the past ten years or three generations). The population size is unknown, precluding the use of Criterion C or Criterion D1, and there exists no quantitative analysis of extinction probability which would permit application of Criterion E.

Therefore, this species is assessed as Vulnerable under Criterion D2, based on its presence at one location with the plausible future threat of climate change that could drive it to Critically Endangered or Extinct in a very short time period.

This species is endemic to Loch Eck in the Eachaig River system, Argyll and Bute council area, Scotland, United Kingdom.

Putatively conspecific subpopulations inhabit Loch Awe in the Awe River system (Argyll and Bute council area), Loch Lee in the North Esk River system (Angus council area), Loch Earn in the Tay River system (Perth and Kinross/Stirling council areas) and Loch Doon in the Doon River system (South Ayrshire council area). However, their identities have never been explicitly confirmed and they are not considered for the purposes of this assessment.

This species' current population size and trend have not been quantified. It is understood to be scarce in Loch Eck, with abundance having declined since the 1990s (see 'Threats').

Naturally oligotrophic Loch Eck was formed after the last glacial period, and comprises a narrow, steep-sided basin with a maximum depth of 42 metres.

Younger's Charr occupies benthopelagic habitats in deeper parts of the lake, but probably undertakes diel vertical migrations related to foraging during warmer months of the year.

It feeds primarily on benthic invertebrates, although zooplankton comprises the major proportion of the diet in summer and autumn.

The annual reproductive period takes place in October, when nuptial individuals develop a conspicuous epigamic colour pattern on the body and fins, and spawning takes place on shallow stony shorelines.

A series of blue-green algae (Cyanobacteria spp.) blooms have been reported in Loch Eck since the early 2010s, but the phenomenon does not yet appear to have been studied in depth.

Warming of the lake due to climate change is a plausible ongoing and future threat.

This species is not used or traded.

This species is included (as Salvelinus alpinus) as a priority species of conservation concern in the U.K. Post-2010 Biodiversity Framework.

Loch Eck lies within the Loch Lomond and Trossachs National Park, and is designated a Site of Special Scientific Interest.

This species is not 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.