Horse-mussel
VU

Horse-mussel

Modiolus modiolus

Unknown

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

Overview

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

Horse-mussels face severe population declines primarily from bottom-trawling fishing activities that physically destroy their reef-like beds, which can take decades to recover. Coastal development and pollution further degrade water quality in their shallow marine habitats, while climate change-induced ocean acidification weakens their calcium carbonate shells. Historical overharvesting for food and bait has also contributed to population fragmentation across their North Atlantic range.

Threat summary

Habitat

Horse-mussels inhabit subtidal rocky and mixed sediment substrates in coastal waters, typically at depths of 5-280 meters throughout the North Atlantic. They form extensive reef-like beds that provide critical three-dimensional habitat structure for numerous other marine species in temperate shelf seas.

MARINE· major

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Unknown

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VU

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Frequently asked questions

Why is Horse-mussel classified as Vulnerable?
Horse-mussel 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. Horse-mussels face severe population declines primarily from bottom-trawling fishing activities that physically destroy their reef-like beds, which can take decades to recover. Coastal development and pollution further degrade water quality in their shallow marine habitats, while climate change-induced ocean acidification weakens their calcium carbonate shells. Historical overharvesting for food and bait has also contributed to population fragmentation across their North Atlantic range.
Where does Horse-mussel live?
Horse-mussel occurs in Australia, Bahamas, Belgium, Belize, Brazil, and Canada (plus 47 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 Horse-mussel?
The main threats to Horse-mussel 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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