VU

Siphlonurus alternatus

Local name: Nordlig svømmedøgnflue

Unknown

Overview

A detailed profile for this species is sourced from the IUCN Red List of Threatened Species as assessments become available.

Siphlonurus alternatus faces significant pressure from water pollution and eutrophication in its Nordic freshwater habitats, which degrades water quality and reduces oxygen levels essential for larval development. Climate change poses an additional threat by altering water temperatures and flow patterns in the cold-water streams this species requires. Habitat fragmentation from hydroelectric development and urban expansion further isolates populations and reduces available breeding sites.

Threat summary

Habitat

This mayfly species inhabits cold, well-oxygenated streams and rivers in northern Europe, particularly in mountainous and boreal regions. The larvae develop in clean, fast-flowing waters with rocky or gravelly substrates, while adults emerge for brief mating flights near these aquatic habitats.

FRESHWATER· major

Threatened in Canada

Calidris ferrugineaVU

Calidris ferruginea

Declining
VU

Nephrotoma lundbecki

Unknown
VU

Large Tree-chernes

Dendrochernes cyrneus

Unknown
VU

Jasmineira caudata

Unknown

Frequently asked questions

Why is Nordlig svømmedøgnflue classified as Vulnerable?
Nordlig svømmedøgnflue is classified as Vulnerable because the population is declining and the species faces a high risk of extinction in the medium-term future if current pressures continue. Siphlonurus alternatus faces significant pressure from water pollution and eutrophication in its Nordic freshwater habitats, which degrades water quality and reduces oxygen levels essential for larval development. Climate change poses an additional threat by altering water temperatures and flow patterns in the cold-water streams this species requires. Habitat fragmentation from hydroelectric development and urban expansion further isolates populations and reduces available breeding sites.
Where does Nordlig svømmedøgnflue live?
Nordlig svømmedøgnflue occurs in Canada, Czechia, Denmark, Estonia, Finland, and France (plus 9 other countries). Country-level distribution data is sourced from the IUCN Red List and cross-referenced with GBIF occurrences.
What are the main threats to Nordlig svømmedøgnflue?
The main threats to Nordlig svømmedøgnflue are ai-1, ai-2, ai-3, and ai-4. The full IUCN-classified threat record for this species is detailed on the species page.

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