twaite shad
CR

twaite shad

Alosa fallax

UnknownLCEULCEU

Photo: Wikimedia Commons (CC) via https://en.wikipedia.org/wiki/Twait_shad

Overview

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

The twaite shad faces severe population declines across its range due to habitat degradation and barriers to migration. Dam construction and river modifications have blocked access to critical spawning grounds, while water pollution and overfishing have further reduced populations to critically low levels.

Threat summary

Habitat

Anadromous fish inhabiting coastal marine waters, estuaries, and lower reaches of rivers along the Atlantic coasts of Europe and North Africa. Adults migrate upstream to spawn in freshwater rivers, typically in areas with gravel substrates and moderate currents.

FRESHWATER· majorMARINE· major

Other threatened species in Clupeidae

Pontic shadVU

Pontic shad

Alosa immaculata

Unknown
EN

Volga shad

Alosa volgensis

Unknown
CR

Thracian Shad

Alosa vistonica

Unknown

Threatened in Åland Islands

Calidris ferrugineaVU

Calidris ferruginea

Declining
Scarce BlackneckCR

Scarce Blackneck

Lygephila craccae

Unknown
EN

knopphodeedderkopp

Walckenaeria nodosa

Unknown
EN

Dolichopus notatus

Unknown

Frequently asked questions

Why is twaite shad classified as Critically Endangered?
twaite shad is classified as Critically Endangered — facing an extremely high risk of extinction in the wild — because population sizes are very small, declining sharply, or restricted to a tiny range. The twaite shad faces severe population declines across its range due to habitat degradation and barriers to migration. Dam construction and river modifications have blocked access to critical spawning grounds, while water pollution and overfishing have further reduced populations to critically low levels.
Where does twaite shad live?
twaite shad occurs in Åland Islands, Albania, Algeria, Australia, Belgium, and Bosnia & Herzegovina (plus 30 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 twaite shad?
The main threats to twaite shad 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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