Spearfishing Stats

Taxonomy

Rarity

Yellowfin tuna are abundant worldwide and very hard for a California diver to get near. Those 2 facts sit together without contradiction. The species lives in tropical and subtropical oceans everywhere except the Mediterranean and is fished commercially across that whole range, but off Southern California it is a seasonal visitor that arrives with warm water and stays well offshore.

The conservation picture improved recently. The International Union for Conservation of Nature moved yellowfin tuna from Near Threatened to Least Concern in its update of 4 September 2021, one of 4 tuna species that showed recovery in the same release. The organization credited countries enforcing more sustainable fishing quotas and cracking down on illegal fishing. That is a global rating, and the same announcement carried a caution alongside it: yellowfin remain overfished in the Indian Ocean, so the worldwide status does not describe every stock.

In the Pacific the picture is better still. NOAA rates the eastern Pacific stock, assessed in 2023, as not overfished and not subject to overfishing, and reached the same conclusion for the central and western Pacific stock in its 2020 assessment. Those are the stocks that reach California.

Regulations

CDFW rules verified 2026-08-20

Seasonality

Edibility

Location

Yellowfin tuna live in tropical and subtropical oceans around the world and are highly migratory, making annual movements to higher latitudes. Southern California sits near the northern edge of that reach. They are an oceanic fish that prefers open water to reef, recorded from the surface down to more than 5,000 feet but spending most of their time in the top 820 feet. NOAA puts their preferred temperature between 64 and 88 degrees Fahrenheit, which is what ties their presence off California to the warmth of a given year.

They school by size, in groups of their own kind or mixed with other species, and the larger fish keep company with porpoises and gather under floating debris. Both habits matter to anyone trying to find them, because the fish themselves are invisible from the surface and their companions are not.

When yellowfin show up off Southern California is a question the sportfishing fleets track more closely than the scientific literature does. The consensus among San Diego and Orange County boats is a season running July through November, peaking in September and October, and starting once surface water reaches about 68 degrees. Warm years bring the fish closer. Strong El Niño conditions have historically produced the best yellowfin fishing the region sees, pushing fish inside 30 miles of the coast, while a cold year holds the bite off until late August or keeps it far out. That pattern comes from fishery reports rather than from a published study, and it should be read as the fleet's accumulated experience rather than as a measured range.

Spearfishing Brief

Yellowfin tuna sit at the top of the difficulty scale for the same reason white seabass do. The hard part is the shot, not the search. Spearfishing sources describe the same animal in nearly identical terms: extremely fast, strong out of proportion to its size, and wary of divers. Most encounters produce a single shooting opportunity and no second chance. That is a 5 for shot difficulty, and it sets the overall rating.

Finding them rates a 4 rather than a 5. A yellowfin is not camouflaged and does not hide in structure, so the difficulty is not in seeing the fish. It is in being in the water with them at all. Off California this means a boat, a season, and the right water temperature, and a full day offshore can end without the diver ever getting in on fish.

The search runs on signs rather than on ground. Divers look for seabirds circling and diving over bait, for fish breaking the surface as they tear into a bait school, and for pods of dolphins and porpoises, since yellowfin travel beneath them while chasing the same prey. That last sign is not folklore. The association shows up in the biology as well, where larger yellowfin are recorded keeping company with porpoises and holding under floating debris. The other common method is chumming from a boat and waiting for fish to come to the bait, and some divers swim the edges of deep drop-offs instead.

Swimming straight at a yellowfin does not work, because the fish reads a diver closing on it and leaves. Community sources agree on 2 alternatives. One is to swim toward a point of intersection well ahead of the fish, or to come in from the up-current side, so the fish holds its line and passes inside range. The other applies to a large fish moving in a straight line and unaware of the diver: some hunters position themselves above it and drop straight down as fast as they can to arrive before it reacts. Shots on free-swimming fish land somewhere between 25 and 65 feet. Placement is not the head shot most people picture. A yellowfin moves too fast for the brain to be a reliable target, and a shot that misses something that small tears out, so hunters aim for the broader area around it.

When choosing a gun, the 2 things that decide it are the range of the shot and the size of the fish, and the community splits into 2 camps. One favors a longer, lighter gun of about 160 cm with 2 bands and a 7.5 mm shaft, on the argument that a diver can move and aim it faster. The other favors a heavy bluewater gun, meaning the open-ocean style of spearfishing done far from any bottom, with at least 4 bands and an 8 to 10 mm shaft, for penetration at 25 to 30 feet. Both camps use a slip-tip, a detachable point that turns sideways inside the fish so it cannot pull back out. Shooting line is Dyneema or 400-pound monofilament, and reels are ruled out entirely, because a yellowfin's first run overwhelms a reel mounted on a gun or a belt. Floats absorb that run instead. A described rig runs about 100 feet of float line to a bungee, then an 11-liter hard float, another bungee, and a 35-liter float behind that. The same rig is the main danger in this fishery. A 60-pound fish is strong enough to drown a diver who gets tangled in the float line.

Deep Dive

The yellowfin is built around movement. It belongs to the mackerel and tuna family, whose members swim continuously and cannot stop, and it grows faster than almost anything else in the open ocean. NOAA has yellowfin reaching 6 feet and up to 400 pounds, able to reproduce at age 2, and living 6 to 7 years. Sources disagree on that last figure. FishBase carries a maximum recorded age of 18 years, nearly 3 times NOAA's number. The figures on this page follow NOAA throughout, because NOAA is the agency that assesses and manages the Pacific stocks that reach California.

They hunt near the top of the food chain, taking fish, squid, and crustaceans. Being large and fast does not put them out of reach of everything else. Documented predators of adult yellowfin include marine mammals, billfish, and sharks, and larvae and juveniles are eaten by fish, seabirds, dolphins, and other animals. The mortality falls almost entirely on the young, which is the ordinary arrangement for a fish that spawns in the numbers this one does.

Reproduction is close to continuous. Yellowfin spawn year-round in tropical water and seasonally at higher latitudes, with peaks in spring and fall. A female can spawn almost daily and release millions of eggs, scattering them into open water along with sperm from the males rather than tending a nest. Nothing about the process involves defending territory or holding a mate, which is why the species shows none of the breeding-season boldness that makes some fish easier to approach.

Far more yellowfin are caught on rod and reel than are ever speared. The Southern California long-range fleet is built around tuna, and yellowfin are one of the species those multi-day trips exist to find. The spearfishing account above describes a small and specialized corner of a fishery whose main business happens with a rod in hand.

The reason for all of that effort is the meat. Raw yellowfin is deep red, firm, and lean, and it cooks brown to grayish-tan and breaks into large flakes. The flavor is mild and meaty, close to swordfish, more pronounced than albacore and less rich than bluefin. It is the tuna most often sliced thin for sashimi and sushi, and it is equally at home seared rare as a steak or cubed for poke. Butchering is straightforward in principle and demanding in practice: the fish is cut into 4 boneless loins, a quarter of the body each, then trimmed of skin and the dark bloodline. There are no fine bones running through the flesh to pick out. What makes the job hard is the size of the animal and the need to bleed it and get it cold immediately, which on a small boat is a scramble.

Where to Find Them

Beaches whose habitats match this species

Matched by habitat: a beach is listed when its biome tags overlap this species' biomes.