VU

Blue Marlin

Makaira nigricans

Declining

Overview

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

Blue marlin populations face severe pressure from intensive commercial and recreational fishing across their range, with longline fisheries posing the greatest threat through both targeted catches and bycatch mortality. Overfishing has led to significant population declines, particularly in the Atlantic where spawning biomass has dropped substantially below sustainable levels. The species' slow growth rate, late sexual maturity, and highly migratory nature make recovery challenging even with conservation measures in place.

Threat summary

Habitat

Blue marlin inhabit tropical and subtropical oceanic waters worldwide, preferring the epipelagic zone above the thermocline where water temperatures exceed 24°C. They are highly migratory, moving between deep offshore waters for feeding and shallower areas near continental shelves and seamounts for spawning.

Marine oceanic· majorMarine neritic· major

Conservation measures underway

Species recovery

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Frequently asked questions

Why is Blue Marlin classified as Vulnerable?
Blue Marlin 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. Blue marlin populations face severe pressure from intensive commercial and recreational fishing across their range, with longline fisheries posing the greatest threat through both targeted catches and bycatch mortality. Overfishing has led to significant population declines, particularly in the Atlantic where spawning biomass has dropped substantially below sustainable levels. The species' slow growth rate, late sexual maturity, and highly migratory nature make recovery challenging even with conservation measures in place.
Where does Blue Marlin live?
Blue Marlin occurs in Mauritius, and Sri Lanka. Country-level distribution data is sourced from the IUCN Red List and cross-referenced with GBIF occurrences.
What are the main threats to Blue Marlin?
The main threats to Blue Marlin 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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