Atlantic Bluefin Tuna are present in the Gulf of Mexico. This region is an important area for the species, serving as a significant part of the western Atlantic Bluefin Tuna’s overall life cycle. Their presence is seasonal, linked to reproductive needs and migratory patterns.
A Crucial Spawning Ground
The Gulf of Mexico is the primary known spawning ground for the western stock of Atlantic Bluefin Tuna, making the area important for the species’ survival. Adult Bluefin Tuna undertake extensive migrations specifically to reach these waters for reproduction.
The Gulf’s oceanographic conditions create an ideal environment for spawning. Spawning occurs when surface water temperatures are between 24°C and 29°C. Tuna favor specific areas along the slope waters, influenced by the Loop Current and cyclonic eddies. These eddies are more productive and slightly cooler than surrounding Gulf currents. Females produce millions of eggs, which are externally fertilized and hatch into larvae within approximately two days.
Seasonal Presence and Migration
Atlantic Bluefin Tuna exhibit seasonal patterns in the Gulf of Mexico, driven by their migratory cycles. The western stock primarily spawns here from mid-April to June.
Mature western Bluefin Tuna forage off the eastern United States and Canadian coasts from June through March. They then migrate to the Gulf for their reproductive season. After spawning, they move northward along the eastern seaboard, sometimes venturing into areas like the Gulf of Maine for feeding. This cyclical movement highlights the importance of both the Gulf of Mexico and their northern feeding grounds.
Conservation and Management
Conservation and management efforts are important for Atlantic Bluefin Tuna in the Gulf of Mexico, given their migratory nature and historical overfishing. International bodies, such as the International Commission for the Conservation of Atlantic Tunas (ICCAT), play a role in setting quotas and establishing management procedures. Domestically, NOAA Fisheries implements these recommendations and develops measures to protect the stock.
Regulations include fishing quotas, size limits, and seasonal closures. Targeted fishing for Bluefin Tuna in the Gulf of Mexico is not permitted. Incidental catches of trophy-sized Bluefin Tuna (73 inches curved fork length or greater) are allowed under a small quota, which can close quickly. Recreational anglers are permitted to catch and release Bluefin Tuna of all sizes, without removing the fish from the water.
NOAA Fisheries implements conservation measures, including Gear Restricted Areas (GRAs) that prohibit pelagic longline fishing in parts of the northern Gulf of Mexico during April and May. These GRAs, totaling approximately 27,000 square miles, were established in 2015 and have proven effective in reducing Bluefin Tuna mortality from longline bycatch. The use of weak hooks by commercial fishermen targeting other species with longline gear is also mandated to reduce incidental Bluefin Tuna catch. These measures are important for the recovery and sustainability of the Bluefin Tuna population.