European regional assessment: Least Concern (LC)
EU 27 regional assessment: Near Threatened (NT)

Most of the range of Aeshna crenata in Europe is found in Russia. Even though the knowledge of the dragonfly fauna there is scarce, the species seems to be quite widespread and at least common in the north and around the Ural Mountains in the south. There is no reason to assume that it is experiencing a decline in this region. The species is therefore assessed as Least Concern on a European level.

The distribution of the species in the Member States of the European Union is very small as it is limited to southern Finland and only nine sites are currently known in Lithuania and Latvia. Paired with the small area of occupancy (456 km²) and that the species is linked to nutrient-poor habitats, the status of which is broadly deteriorating, indicates a future risk of a rapid decline in population of around 20%. Even a small negative impact overall on the habitats or a direct impact on local sites can threaten the species' existence. It is therefore assessed as Near Threatened (A3c; B2b(iii)) in the EU27.

The vast majority of the species' range is in Russia, in the temperate belt from north-eastern Europe east to Kamchatka, Sakhalin, South Korea and Japan. Locally, A. crenata can also be found north of the Arctic Circle.

In Europe, it is known from several dozen sites in southern Finland, from eight sites in eastern Lithuania, one in south-eastern Latvia and two in north-eastern Belarus. Most likely, it is rather uncommon in most of European Russia, from which, however, we have rather scant information. It is reasonably common in the southern parts of the Ural Mountains and probably also in the northern part of European Russia (Bernard and Kalkman 2015, Kitel 2022).

In the European part of its range, the species is rather rare with large distances between the known populations in the Baltic states and Belarus. Even though seemingly suitable environments exist in large parts of the Nordic countries, the species occurs there only in Finland where its presence appears to be stable. In Finland, it is found mainly in the south and southeast, and it is only found locally in eastern Lithuania (eight sites), in south-eastern Latvia (one site) and in north-eastern Belarus (two sites). Most of its European distribution is in Russia and for this area, there is only scant information about its population sizes and distribution. It seems to be at least common in northern Russia and in the Urals. Based on the limited information, it seems that the population density in suitable habitats in Russia varies from tens to several hundred specimens, but in Finland, it generally occurs in smaller numbers (maximum 13 individuals) (Kalkman 2010, Kitel 2022, Korkeamäki et al. 2012).

A. crenata is in Finland found in nutrient-poor, rather small lakes and ponds that are well vegetated with Sphagnum at the edges, surrounded by old forest. The sites are lowland (90-115 m asl) glacial formations, influenced by clear groundwater and free of contaminants. The largest populations are found in fish-free water bodies. In Russia, where it is more widespread, it is also found in other types of habitats such as along margins of larger lakes, and oxbows with vegetation of Equisetum fluviatile and Carex (Kalkman 2010, Korkeamäki et al. 2012, Korkeamäki 2013).

The male of A. crenata often patrols 1.5–2 meters above the water surface. The patrol takes place along the water edges where it looks for females. The male can be very aggressive and chase away males of other species. It is a relatively stationary species, rarely seen far from its reproduction sites, although individuals can be found along forest roads, in clearings and similar environments. In Finland, it starts to emerge at the end of June with the last individuals on its wings into early September. It often rests directly on tree trunks adjacent to its preferred aquatic habitats. The eggs are laid along the edge in Sphagnum, in Carex or among parts of water lilies, rotting wood and other organic plant material both in and just below the water surface. The larva is the largest in the genus and the development probably lasts three years or longer. The exuvia is found in knee-deep or slightly deeper water on upright material (Billqvist et al. 2019).

The majority of the known populations of the species in Europe are located in areas with relatively little human direct impact. Deforestation, even small-scale, can however be a threat if it occurs in connection with the sites. As the species mainly occurs in relatively fish-poor environments, the introduction of fish can locally be a threat. Most of the distribution of A. crenata is probably situated so far north that the threats shared by other nutrient-poor species further south has yet to make an impact. The distribution of the species in the Member States of the European Union is however very small, as it is limited to southern Finland and only nine sites are currently known in Lithuania and Latvia. Paired with the small area of occupancy (456 km²) and that the species is linked to nutrient-poor habitats, the status of which is broadly deteriorating, indicates a future risk of a rapid decline. Even a small negative impact overall on the habitats or a direct impact on local sites can threaten the species' existence in this region.

There is no trade or use of this species.

There is currently no need for special conservation measures. However, the few sites known in the Baltic States and Belarus should be monitored and further studies may provide more information on the state of the sites and perhaps find additional locations. The situation for the species in the European part of Russia is very poorly known. Field work throughout the northern part of Russia is needed. Based on this, an assessment should be made of the conservation status. It should be determined whether this species is present in protected areas. If not, new protected areas should be created.