Circle Hooks: How They Work, How to Fish Them, and Where They Are Law

Circle hooks are hooks whose point curves back toward the shank, so far that the gap between them is a near-circle, and they catch fish by a different mechanism from every other hook: the angler does not strike. A fish takes the bait, turns and swims off; the line comes tight, the hook slides out of the throat and along the jaw until it reaches the corner of the mouth, and there the curved point rotates and sets itself. North Carolina’s regulators define it as a hook “with the point pointed perpendicularly back toward the shank” and the point and barb in the same plane as the shank, which is what “inline” or “non-offset” means. The result, in the science and in the regulations that followed it, is far fewer gut-hooked fish. Below: how to fish one, the research, the rules by jurisdiction, sizes by fish, and where a circle hook is the wrong choice.

Point the rod at the fish and reel. The hook does the rest. Strike, and you pull it straight out of the mouth.

How to fish a circle hook

Maine’s Department of Marine Resources gives the instruction in one sentence: “simply point the tip of the rod at the fish and slowly begin to reel in. The hook will set itself, usually in the corner of the mouth.” Everything else follows from that.

1. Bait it lightly. Hook the bait once through a corner so the gap stays open; a bait that plugs the gap stops the hook turning. For cut bait, once through the skin; for a live shad or bluegill, through the nose or behind the dorsal.
2. Leave the rod in the holder or hold it with the bail closed and the drag set light, or with the bait clicker on a baitcaster, so the fish can take the bait and turn.
3. Wait for the rod to load. The tip pulls down and stays down as the fish moves off; that is the fish hooking itself.
4. Reel. Steadily, rod pointed at the fish, until the rod bends fully. Then lift and fight the fish.
5. Never set the hook. A snap of the rod at the first tap pulls the circle hook out of the mouth before it has reached the corner; the commonest reason anglers say circle hooks do not work.

On a bottom rig the fish’s own movement against the sinker does the setting; the slip-sinker rig on the catfish rigs page is built around a circle hook for that reason.

The research

Cooke and Suski’s 2004 review of the studies to that date, the reference every regulator cites, found that circle hooks reduced mortality by about half relative to conventional J hooks, with more fish hooked in the jaw and fewer in the gut or gills, and that the effect varied with hook size, fishing style, the fish’s feeding mode and the shape of its mouth. That variation is why the rules that followed specify natural bait, where fish swallow, and not lures, where they do not. The catch and release page carries the mortality figures for the other choices, barbless hooks and handling.

Where circle hooks are the law

The rules are as reported by the agencies linked in the sources on the date this page was written; every one of them changes, and the state’s current regulation page is the authority. The pattern is consistent: natural bait, non-offset, non-stainless, so the hook rusts out if a fish is lost with it.

Sizes by fish

The catfish sizes are the FishUSA and Catfish Pro consensus; the saltwater sizes the Academy chart. Circle hooks run large for their number because the gap is what matters, and a circle hook one or two sizes bigger than the J hook you would have used is normal. The what size hook for catfish page has the catfish table by bait size, and the hook size chart explains the numbering.

When not to use one

• Lures. A lure is struck, not swallowed; a J hook or treble sets on the strike and a circle hook mostly does not.
• Soft, small baits for small-mouthed fish. Trout and panfish take a worm into the mouth and a circle hook’s gap is too big to turn in a small jaw; a small J or Aberdeen hooks more.
• Anglers who cannot stop striking. Habit sets the hook before the fish has turned; if you cannot leave the rod alone, a Kahle hook, halfway between J and circle, forgives both styles.
• Offset circle hooks where the rule says non-offset; an offset point, bent out of the plane of the shank, hooks more fish and gut-hooks more too, which is why the regulations exclude it.

Related

The hooks hub covers the ten hook types; the types of hooks page sets the circle beside the octopus, Kahle and J it is confused with; the treble hook page covers the other regulated hook. For the fish, the catfish hub is where circle hooks do most of their work in fresh water.