Although this species' population trend may be decreasing due to habitat degradation, there is no evidence that the rate of decline approaches the minimum threshold for Vulnerable under Criterion A (≥ 30% over the longer of 10 years or 3 generations). It does not approach the range thresholds for Vulnerable under Criterion B (extent of occurrence (EOO) < 20,000 km², area of occupancy (AOO) < 2,000 km²) or D2. The population size far exceeds 10,000 mature individuals, hence it does not approach the thresholds for Criteria C or D. There exists no quantitative analysis which would permit application of Criterion E.

Therefore, the Common Dace does not currently meet the thresholds for any Red List criteria, and it is assessed as Least Concern.

This species is present across the majority of Europe in addition to a small part of Central Asia.

In the European Atlantic basin, it occurs from southeastern Norway to the Seine River system in northern France, and throughout much of Great Britain except western Wales and Scotland, where it is native only in the Tweed River system.

Across the remainder of Europe it inhabits rivers draining to the Baltic, White, Barents and northwestern Black sea basins, plus the Rhône River system in the Mediterranean Sea basin.

In Central Asia, it occurs in the Volga and Ural river systems, which drain to the northern Caspian Sea basin.

It has been introduced to southern Ireland and parts of Scotland, including the Loch Lomond basin.

This species' population size is unknown, but it far exceeds the minimum threshold for Red List criteria (< 10,000 mature individuals). The current population trend has not been quantified, and any accurate estimation is complicated by a shortage of relevant information from the majority of its range. The number of subpopulations is also unclear.

It has declined significantly in some countries (e.g., Belgium, Poland) since the mid-20^th century, although it remains widespread and can be abundant where suitable habitat conditions prevail. Recent reports suggest that it is declining in France, but stable in Germany and Switzerland.

This gregarious, rheophilic species inhabits flowing stretches of rivers and larger streams, although it also enters fluvial lakes and has become widely established in artificial canals and reservoirs. During the winter, large groups of adults congregate in backwaters or the lower reaches of rivers.

Its diet largely comprises aquatic macroinvertebrates alongside smaller quantities of algae and detritus. During warmer periods, it often feeds on terrestrial insects at the water surface. The precise composition of the diet varies with ontogeny, location and season.

In Ireland, it is considered to be invasive and is believed to exert negative pressure on native salmonid stocks through competition for food and spawning sites.

The maximum recorded lifespan is c. 15 years, and sexual maturity is normally attained at age 3+. Older individuals can weigh in excess of 0.5 kilogrammes, and mean fecundity is c. 40 eggs per gramme of body weight.

The annual reproductive period occurs between February and May, depending on location, when mean daily water temperatures rise above c. 9-10°C. It is characterised by sometimes lengthy migrations to specific upstream spawning sites comprising gravel banks in shallow, fast-flowing water. Whereas some subpopulations migrate within larger river channels, others move into tributaries to spawn.

Males aggregate densely at spawning sites, and aggressively compete to maintain an optimal position. Individual females produce a single batch of eggs per year, but may spawn annually for up to seven years.

Spawning itself often takes place during a brief period of 3-5 days, after which adults return to their foraging grounds.

The adhesive eggs attach to the substrate and hatch around four weeks after spawning.

Early-stage larvae typically drift downstream and settle in shallow littoral habitats, which also function as nursery zones. Once free-swimming the fry initially feed on pelagic zooplankton, but with increasing size gradually move into areas with stronger currents where the diet shifts to larger invertebrates.

The Common Dace occasionally hybridises with related species, including Common Bleak (Alburnus alburnus), Ide (Leuciscus idus) and European Chub (Squalius cephalus).

This species is plausibly threatened by river regulation and other forms of habitat degradation, which have driven widespread loss of the heterogeneous, interconnected fluvial habitats required for migratory freshwater fish species to complete their life-cycles.

In particular, the construction of dams, weirs and other barriers has altered natural flow and sedimentation regimes and is likely to have blocked migration routes, fragmented subpopulations, and reduced the extent of suitable habitat for all life stages. The quality of available habitat has been further diminished by bank stabilisation, channelisation and other efforts to enhance flood protection or river transportation links.

It is also likely to have declined due to widespread agricultural, domestic and industrial pollution during the 20^th century, some of which persists today.

For example, increasing nutrient levels have driven eutrophication and increased water turbidity throughout its range, resulting in a decrease in the quality of foraging and spawning sites.

It is plausible that certain herbicides, pesticides and industrial pollutants cause direct mortality or impair reproduction when present in sufficient concentrations.

There exist few publications investigating the effect of these potential threats on Common Dace subpopulations, but a range of negative outcomes have been documented for other fish species with comparable habitat preferences and life histories.

This species is consumed locally in some parts of its range, but has no major commercial importance.

It is routinely targeted by recreational anglers, and is sometimes used as a bait fish.

This species occurs within the boundaries of numerous protected areas. In European Union member states, some of these are included in the Natura 2000 network, and it may also have benefitted from efforts to improve the ecological status of rivers within the structure of the European Water Framework Directive.

The latter legislation was implemented in 2003 and has alongside a general decline in heavy industry resulted in improving water quality across much of its range. Pollution has in many areas been reduced, while management actions focussed on freshwater fishes have included measures to improve habitat quality, e.g., restoration of spawning sites or stream banks, or connectivity, e.g., dam-removal projects or installation of nature-like fishways to re-establish migration routes.

Initial efforts investigating the potential of ex situ artificial reproduction using hormones have taken place in Poland, but it is unclear whether captive stocks have subsequently been established, or whether any release of reared individuals to natural habitats has taken place.

This species' global conservation status has not been extensively studied, and it is recommended that future research should focus on understanding its current distribution and population trends over a range of spatial scales. A deeper understanding of its life history and response to the identified threats would also be beneficial in order to identify whether any conservation actions are necessary. Given the extent of its range, such efforts would be best coordinated at local or regional scales.