A Guide to the Tunas of the Western Atlantic Ocean

INTRODUCTION

The national Marine Fisheries Service (NMFS) has developed this pamphlet, A Guide to the Tunas of the Western Atlantic Ocean, to assist commercial, charter/headboat and recreational users and dealers/buyers in identifying the seven regulated Atlantic tuna species (bluefin, bigeye, yellowfin, skipjack, albacore, blackfin, and bonito), as well as the one unregulated Atlantic tuna species (little tunny). The Atlantic tuna fisheries occur in all waters of the Eastern United States, from the Northeast (Gulf of Maine) to the Mid-Atlantic, Southeast, Caribbean, and Gulf of Mexico Regions. As of December 1996, there were in excess of 28,000 permitted vessels that participate throughout the year in the tuna fisheries. These vessels are regulated under the Magnuson Fishery Conservation and Management Act (ATCA) which provides authority to implement international agreements reached by the International Convention for the conservation of Atlantic Tunas (ICCAT).

The status of a fishery resource describes the relative condition of a population as compared to the long term potential yield that a particular species may provide. The current status of Atlantic tunas are as follows; bigeye, yellowfin, albacore, and skipjack-fully utilized; bluefin tuna- over utilized. Management measures are in place to sustain or rebuild these populations. All users play a role in this effort by complying with regulatory measures. Identifying and understanding the species for which one is fishing is a first step towards sound conservation. Proper identification of tuna species is essential in order to prevent landings which exceed current regulations.

Some species of tuna (particulary juveniles) are difficult to identify, and it is often difficult ti identify a tuna using only one physical feature. The best identification technique is to distinguish two or more features of the fish, such as pectoral fin length and gill raker count, and identify the species through the process of elimination.

ATLANTIC TUNAS PERMIT PROGRAM

All owners/operators of vessels (commercial, charter/headboat, or recreational) harvesting regulated Atlantic tunas (bluefin, bigeye, yellowfin, skipjack, albacore, blackfin, and bonito) and all fish dealers must obtain an Atlantic Tunas Permit.

Vessel owners wishing to fish recreationally for Atlantic bonito are exempt from the requirement to obtain an Atlantic tunas permit. Commercial and charter/headboat vessel owners are required to obtain an Atlantic tunas permit to fish for Atlantic bonito.

Atlantic tunas permits are issued in six categories. The commercial categories are; General, Charter/Headboat, Harpoon Boat, Purse Seine, and Incidental Catch. The Angling category is the recreational category. Only one category may be assigned to a vessel.

Atlantic tunas may be sold only by fishers permitted in commercial categories and may be sold only to permitted dealers. Atlantic tunas taken recreationally or by persons aboard Angling Category vessels may not be sold.

NMFS has implemented a new Automated Permitting System (APS) to apply for and renew Atlantic Tunas Permits. The APS can be accessed by dialing 1-888-USA-TUNA (1-888-872-8862) or through the internet at: www.usatuna.com Atlantic Tunas permits must be renewed annually for the calendar year (January 1- December 31), and there is an $18 annual permit processing fee. Customer service for the APS can be reached at 1-800-663-3879.

NOTE: permit applications may take up to 30 days process, and change of permit category may be made from January 1 to May 15 only. Only one permit category change is permitted each year.

USING THE GUIDE

(1) Body parts and measurements used in identifying Tuna illustrates the general external and internal physical characteristics that fishers can refer to when identifying tuna.
(2) Observations to help identify Tunas describes the physical characteristics used to distinguish the various species from one another.
(3) Reference Key to Atlantic Tunas characterizes, in table format, anatomical features that may be used to identify tuna.
(4) List of Species provides a picture of each species with common and scientific names, distinctive characteristics used to identify the species, maximum and common sizes (in inches), and a brief description of general distribution and behavior. All lengths given in this guide, unless otherwise indicated, refer to total straight fork length.

Please carry this guide with you, aboard your vessel, when fishing for large pelagic species (you never know when you might need it). If you have questions concerning this guide or Atlantic regulations, refer to the list of NMFS employees found at the back of the pamphlet.

OBSERVATIONS TO HELP IDENTIFY TUNAS

1) Look at the fins. If the pectoral fin, when held flush to the side of the tuna's body ends well before the origin of the second dorsal fin, it is probably a bluefin tuna. If the pectoral fin extends to or past the origin of the second dorsal fin, then it is likely either a bigeye or yellowfin. A tuna with extremely long pectoral fins, extending beyond the origin of the anal fin, is most likely an albacore. A tuna over forty pounds with extremely long anal and second dorsal fins is most likely a yellowfin.
2) Count the gill rakers on the first gill arch and observe the liver for its shape and presence of striations. This information, combined with fin shape and size, should permit correct identification of the species.
3) Headed and gutted yellowfin tuna have a distinct, white fleshy round node (like a fleshy cord) that runs along the top of the body cavity from front to rear. This is absent in bigeye and bluefin.
4) Headed and gutted bluefin tuna have a distinct pocket that can be felt by running your hand along the inside of the body cavity underneath the insertion of the pectoral fin. Yellowfin and bigeye tuna do not have this indentation in their body cavity.

CURVED FORK LENGTH MEASUREMENT

Total curved fork length is the sole criterion for determining the size class of whole (head on) Atlantic tunas for regulatory purposes. Curved fork length means a measurement of the length of a tuna taken in a line tracing the contour of the body from the tip of the upper jaw to the fork of the tail, which abuts the upper side of the pectoral fin and the upper side of the caudel keel.The measuring tape must pass over (and touch) the pectoral fin and the caudal keel.