What You're Looking For When You Fish for Sixgill Sharks

Sixgill sharks are deep-water predators that live in cold, dark ocean trenches and canyons, usually between 600 and 3,000 feet down. They are one of the most primitive shark species alive — their lineage goes back 200 million years — and they are built for hunting in the abyss rather than for speed or aggression near the surface. A sixgill is a massive, slow-moving animal with a blunt snout, a single dorsal fin, and six gill slits instead of the five that most modern sharks have. Adults typically reach 14 to 16 feet, though specimens over 18 feet have been documented.

Sixgills are not a target species for most recreational anglers because they live so deep and move so slowly that conventional fishing methods do not work. The few people who encounter them do so by accident — usually while bottom-fishing for other deep-water species in canyons off the continental shelf, or during specialized deep-sea expeditions. If you hook one, you are dealing with an animal that can weigh 1,000 pounds or more and has the strength to exhaust even heavy tackle over hours. Most encounters end with the line breaking or the angler choosing to cut it rather than fight an animal that cannot be safely brought to the surface.

Key Takeaways

  • Sixgill sharks live in deep canyons and trenches 600 to 3,000 feet below the surface, so you need a boat equipped for deep-water fishing and heavy tackle rated for extreme depths.
  • They are most reliably found off the coasts of California, the Pacific Northwest, and parts of the Atlantic, particularly near submarine canyons where the shelf drops away sharply.
  • Sixgills are scavengers that feed on dead fish and whale carcasses, so bait fishing with mackerel, squid, or other oily fish is the only method that works at those depths.
  • Bringing a sixgill to the surface causes decompression injury because of the pressure change, so most anglers who hook one intentionally cut the line to avoid harming the animal.
  • No recreational fishery for sixgills exists in the United States, and they are protected under various state and federal regulations that prohibit landing them in most regions.

Where Sixgill Sharks Live and When to Find Them

Sixgills are found in oceans worldwide, but the most accessible populations for North American anglers are off the Pacific coast. The Monterey Canyon in central California is the most famous location — the canyon walls drop to 6,000 feet, and sixgills hunt in the deeper sections year-round. The Tanner Canyon and other submarine canyons off Southern California also hold sixgills, as does the Quinault Canyon off the Washington coast. In the Atlantic, they occur off the coasts of New England and the Mid-Atlantic, particularly in deep canyons like the Hudson Canyon off New Jersey, though they are less frequently encountered there.

Sixgills do not migrate seasonally in the way that many other sharks do. They stay in deep water year-round because the temperature and pressure at those depths remain stable. However, they are more active during winter months when surface waters cool and upwelling brings more food to the canyons. Late fall through early spring is the window when deep-water expeditions are most likely to encounter them, though weather conditions and sea state often limit when boats can safely operate in canyon waters.

The best time to fish for sixgills is during slack tide or when current is minimal, because strong currents in canyons make it nearly impossible to keep bait on the bottom where sixgills hunt. Most charter operations that target deep-water species time their trips around tidal windows, and if you are booking a boat, the captain will know the optimal windows for your target canyon.

What Sixgills Eat and How to Bait for Them

Sixgills are scavengers and ambush predators. They feed primarily on dead fish, whale carcasses, and other organic matter that sinks to the ocean floor. They have poor eyesight but an extremely sensitive sense of smell, so they locate food by detecting chemicals in the water column. This means bait fishing is the only method that works — you cannot catch a sixgill on lures, and fly fishing is not relevant at those depths.

The most effective baits are oily fish that release a strong scent into the water: mackerel, squid, herring, and bonito are all used by anglers and charter captains who fish deep canyons. Bait is typically fished on the bottom in large chunks, often weighing several pounds, because sixgills are large animals and small baits are ignored. The bait is rigged on heavy circle hooks — usually 10/0 to 14/0 — and lowered to the bottom on wire or heavy braided line. Sinkers of 2 to 4 pounds are common, depending on depth and current.

Patience is essential. A sixgill may take an hour or more to locate and consume the bait, and you may fish an entire day without a bite. Charter captains who specialize in deep-water fishing often fish multiple lines simultaneously to increase the odds of an encounter.

Tackle and Boat Requirements for Deep-Water Fishing

Sixgill fishing requires heavy conventional tackle — not spinning gear. A typical setup uses a boat rod rated for 50 to 80 pounds of line, paired with a large conventional reel (often called a boat reel or big-game reel) that holds at least 500 yards of line. The line itself is usually 50- to 80-pound braided line, which has less stretch than monofilament and allows you to feel what is happening on the bottom in deep water.

The boat must be equipped with a depth finder capable of reading depths beyond 1,000 feet, GPS navigation for pinpointing canyon locations, and safety equipment for open-ocean fishing. Most sixgill encounters happen from charter boats specifically outfitted for deep-water fishing, because private boats rarely have the equipment or the experience necessary to safely fish canyons. Charter captains know the locations of sixgill populations, understand tidal windows, and have the expertise to handle the extreme conditions of canyon fishing.

If you are considering a deep-water charter, confirm in advance that the boat is insured for deep-water operations and that the captain has experience with sixgills or other deep-water sharks. Not all charter operations venture into canyons, and those that do charge premium rates — often $1,500 to $3,000 or more for a full day — because fuel costs, insurance, and expertise are all significantly higher than for conventional fishing.

Regulations and Why You Cannot Keep a Sixgill

Sixgill sharks are protected under federal law in U.S. waters. The Magnuson-Stevens Fishery Conservation and Management Act lists sixgills as a prohibited species, which means they cannot be landed, retained, or sold. If you hook a sixgill, you are required by law to release it immediately. Some states have additional protections that extend to all deep-water shark species, so regulations may be even stricter depending on where you are fishing.

The protection exists because sixgills are slow-growing, long-lived animals with low reproductive rates. They do not reach sexual maturity until they are 20 to 30 years old, and they produce only a small number of offspring. This means that even modest fishing pressure can deplete populations over time, and recovery is extremely slow. Commercial fishing for sixgills has been banned in most developed nations for the same reason.

In practice, most anglers who hook a sixgill never bring it to the surface. The pressure change from 1,000 feet of depth to the surface causes severe decompression injury — the shark's swim bladder ruptures, its eyes bulge, and it cannot survive even if released. Experienced anglers cut the line as soon as they recognize they have hooked a sixgill, which is the most humane option and also complies with the spirit of the protection.

What Happens If You Hook a Sixgill

The bite of a sixgill is distinctive: it is not a violent strike but a steady, powerful pull. The fish takes the bait and begins moving away from the bottom with relentless pressure. Because sixgills are slow swimmers, the fight is not about speed — it is about sheer weight and endurance. A large sixgill can take 30 minutes to an hour to fight to the surface, and the angler is doing most of the work, not the fish.

If you are fishing with a charter captain, they will likely recognize the bite pattern and tell you to cut the line. If you are fishing alone and unsure, the safest approach is to stop fighting and cut the line once you realize the fish is extremely large and the fight is not progressing. Attempting to land a sixgill causes unnecessary suffering to the animal and violates federal protection regulations.

Some anglers and researchers do pursue sixgills for tagging and scientific study, but this requires permits from NOAA Fisheries and coordination with research institutions. These operations use specialized equipment and protocols to minimize harm, and they are not open to recreational anglers.

Alternatives: Other Deep-Water Species You Can Actually Keep

If you want to fish deep canyons but are interested in species you can retain, several options exist. Rockfish (also called ocean perch or red snapper) live at depths of 400 to 1,500 feet and are abundant in canyons off California and the Pacific Northwest. They are excellent eating and are managed as a sustainable fishery with specific bag limits and seasons. Lingcod and sablefish (black cod) are also found in deep water and are legal to keep in most regions.

Deep-water halibut fishing is another option, particularly off Alaska and the Pacific Northwest. Halibut live on the bottom at depths of 600 to 1,500 feet and are a premier food fish. Charter boats that target halibut use similar tackle and techniques to those used for sixgill fishing, but the experience is more rewarding because you can legally land and keep your catch.

If you are interested in sharks specifically, several species are legal to fish in coastal waters at shallower depths. Blue sharks, makos, and threshers are all found off the California and Atlantic coasts and can be targeted from boats equipped for shark fishing. These species are much more accessible than sixgills and offer a genuine fishing experience rather than an accidental encounter.

Frequently Asked Questions

Can I fish for sixgills as a recreational angler?

Sixgills are protected under federal law and cannot be retained or landed. Recreational fishing for them does not exist as a legal activity. If you hook one while deep-water fishing for other species, you must release it immediately by cutting the line.

How deep do sixgill sharks live?

Sixgills typically live between 600 and 3,000 feet deep, though they can be found at depths exceeding 6,000 feet in submarine canyons. They are rarely found in shallow water and do not migrate to the surface.

What is the biggest sixgill shark ever caught?

The largest confirmed sixgill sharks have exceeded 18 feet in length and weighed over 1,000 pounds. Most encounters are with smaller individuals in the 12- to 16-foot range, but the species can grow significantly larger.

Why do sixgills die if you bring them to the surface?

Sixgills are adapted to extreme pressure at depth. When brought to the surface rapidly, the pressure change causes decompression injury — their swim bladder ruptures, their eyes bulge, and internal organs are damaged. They cannot survive this transition even if released.

Where is the best place to see a sixgill shark?

The Monterey Canyon off central California is the most reliable location for sixgill encounters. Specialized deep-sea submersible tours and research expeditions occasionally film sixgills in their natural habitat, which is the best way to observe them without harming the animal.