The population status of Atlantic skipjack tuna is a crucial aspect to consider when evaluating its sustainability. According to the 2014 stock assessment, Atlantic skipjack tuna is neither overfished nor subject to overfishing. This assessment demonstrates that the species is currently managed effectively and responsibly under U.S. regulations.
To ensure the sustainability of skipjack tuna, the International Commission for the Conservation of Atlantic Tunas (ICCAT) actively assesses the abundance of the species and evaluates the sustainability of existing and proposed harvest practices. By utilizing scientific information derived from these assessments, ICCAT formulates management recommendations aimed at maintaining healthy populations of skipjack tuna.
The appearance of skipjack tuna is distinctive and captivating. Unlike many other fish species, skipjack tuna do not possess scales throughout their bodies, except for the corselet—a band of large, thick scales behind the head. However, they do exhibit a faint lateral line that runs lengthwise down each side of their bodies.
The back of skipjack tuna showcases a dark purplish blue hue, while their lower sides and belly glisten with a silvery sheen. Notably, they bear four to six conspicuous longitudinal dark bands, which may resemble continuous lines of dark blotches. This vibrant coloration adds to their allure, making them visually captivating both in the water and on the plate.
The biological characteristics of skipjack tuna contribute to their unique ecological niche. These tropical tunas exhibit rapid growth, reaching lengths of over 3 feet and weights of up to 40 pounds. However, their life span remains relatively short, typically lasting around 7 years.
In the eastern Atlantic, skipjack tuna begin reproduction at the age of 1 year. They engage in spawning throughout the year in tropical waters and seasonally (spring to early fall) in subtropical regions. Females, depending on their size, can produce between 100,000 and 2 million eggs annually.
Remarkably, skipjack tuna are capable of spawning multiple times within a single season, sometimes as frequently as once per day. The fertilized eggs hatch within approximately 1 day, contingent upon the water temperature. This reproductive resilience contributes to the stability of their populations.
Skipjack tuna exhibit opportunistic feeding habits, preying on a diverse range of organisms such as fish (e.g., herrings), crustaceans, cephalopods, mollusks, and occasionally other skipjack tunas. They also serve as a vital food source for larger pelagic fishes, including billfish, sharks, and other large tunas.
Skipjack tuna inhabit tropical, subtropical, and warm temperate waters across all oceans. In the western Atlantic, they can be found stretching from Massachusetts to Brazil, encompassing the Gulf of Mexico and the Caribbean. Their habitat preferences contribute to their high degree of versatility and adaptability.
As pelagic species, skipjacktuna primarily reside in the open ocean, although they may spend certain periods of their lives in nearshore waters. They display a preference for surface waters and can venture to depths of up to 850 feet during the day. At night, they tend to remain closer to the surface.
The migratory nature of skipjack tuna is another fascinating aspect of their habitat. They undertake long-distance journeys to feed and reproduce. Often forming schools, these tuna exhibit a particular affinity for floating objects, convergence zones, and boundaries between cold and warm water masses. They also congregate around upwelling areas where nutrient-rich water replaces the nutrient-depleted surface water.
To maintain the sustainability of the Atlantic skipjack tuna fishery in the United States, NOAA Fisheries and the Atlantic Highly Migratory Species Division have implemented comprehensive management measures. These measures are outlined in the Consolidated Atlantic Highly Migratory Species Fishery Management Plan. Here are some key aspects of the management:
Permit Requirement: Commercial fishermen must obtain a permit to harvest skipjack tuna, ensuring regulated access to the fishery.
Gear Restrictions: The use of handgear, including rod-and-reel and handline gear, is prevalent among U.S. commercial fishermen targeting skipjack tuna. These methods are highly selective, minimizing unintended catch and habitat impacts. Handgear does not contact the ocean floor, further reducing potential ecological disturbances.
Consistency with Federal Regulations: Federal management regulations for Atlantic tunas apply to state waters, with the exception of Maine, Connecticut, and Mississippi. NOAA Fisheries regularly reviews state regulations to ensure their alignment with federal guidelines.
International Cooperation: As skipjack tuna are highly migratory, their management necessitates international collaboration. The United States actively participates in regional fisheries management organizations like ICCAT, contributing to global tuna conservation efforts. NOAA Fisheries implements regulations for the U.S. western Atlantic skipjack tuna fishery based on scientific findings and conservation measures endorsed by ICCAT.
Monitoring and Reporting: In 2013, ICCAT adopted a measure to expand reporting requirements for tropical tuna fisheries that utilize fish aggregating devices (FADs). This measure enhances data collection and enables scientists to better understand the fishing effort associated with FAD fishing.
Furthermore, the United States established the Dolphin-Safe Tuna Tracking and Verification Program in 2000. This program monitors the domestic production and importation of frozen and processed tuna products, ensuring the authentication of dolphin-safe claims.
In the commercial fishery sector, skipjack tuna constitute a minor component of total U.S. tuna landings and only a small percentage of the international landings of western Atlantic skipjack tuna. In 2020, the United States contributed less than one percent of the total western Atlantic skipjack landings. Commercial landings of Atlantic skipjack tuna in 2021 amounted to 780 pounds, with a value of $1,000.
Commercial fishermen in the Atlantic predominantly utilize handgear methods for harvesting skipjack tuna. These methods, such as rod-and-reel and handline gear, are highly selective, minimizing impacts on the marine environment. Additionally, handgear does not pose risks to the ocean floor.
Recreational fishermen play a more substantial role in the total catch of skipjack tuna in the western Atlantic. In 2021, recreational landings of skipjack tuna reached approximately 100,000 pounds. To engage in recreational fishing for skipjack tuna, anglers must obtain a permit.
Recreational fishing for highly migratory species like skipjack tuna delivers significant economic benefits to coastal communities through expenditures by individual anglers, recreational charters, tournaments, and associated shoreside businesses.