Long lining refers to two very different practices depending on context. In commercial fishing, it’s a method of catching fish using a main line strung with hundreds or thousands of baited hooks. In horse training, it’s a groundwork technique where a handler guides a horse using two long reins without riding. Both are widely practiced, and if you searched this term, you likely want to understand one or both.
Long Lining in Commercial Fishing
Longline fishing deploys a single main line, sometimes stretching for miles, with shorter branch lines (called “snoods” or “gangions”) clipped at intervals along its length. Each branch line ends in a baited hook. The main line has a larger diameter than the branch lines and bears the combined load of the entire setup, including floats that keep sections of the line at the desired depth. A single set can carry thousands of hooks behind the boat.
There are two main types. Pelagic longlines suspend hooks near the ocean surface to target open-water species like tuna, swordfish, and marlin. Demersal longlines sit on or near the ocean floor and target bottom-dwelling species like halibut, sablefish, and cod. The distinction matters because the depth of the gear determines what gets caught, both intentionally and accidentally.
Bycatch and Environmental Concerns
The biggest criticism of longline fishing is bycatch: the unintended capture of non-target species. Sea turtles, sharks, seabirds, and rays all take baited hooks meant for commercial fish. This is especially problematic in pelagic fisheries, where hooks hang in the water column and attract a wide range of animals.
Hook design makes a measurable difference. Switching from traditional J-shaped hooks to circle hooks (which are rounded and less likely to be swallowed) reduces sea turtle catch rates significantly. Studies of shallow-set pelagic longlines found that circle hooks reduced loggerhead sea turtle retention by about 49%, leatherback retention by 61%, and olive ridley retention by 43%. For sharks, circle hooks lowered the rate of death on the line by 11% to 22% depending on species, with blue sharks seeing the largest benefit.
Other mitigation tools include weighted lines that sink faster, reducing the window when seabirds can grab bait near the surface, and bird-scaring streamers (called tori lines) trailed behind the vessel during setting. Fisheries certified by the Marine Stewardship Council, such as those targeting Patagonian toothfish in the Southern Ocean and cod in Icelandic waters, use combinations of these measures to meet sustainability standards.
Regulations on Longline Gear
In the United States, NOAA regulates longline fisheries with gear-specific rules. In the Hawaii deep-set longline fishery, for instance, steel wire leaders are prohibited within one meter of any hook. This makes it easier for sharks and other large bycatch to break free. Fishermen in several Pacific longline fisheries are also required to remove trailing gear from oceanic whitetip sharks they catch, reducing post-release injury and mortality.
These rules vary by region and target species, but the trend across most regulated fisheries is toward gear modifications that reduce harm to vulnerable species while maintaining commercial viability.
Long Lining in Horse Training
In the equestrian world, long lining (sometimes written as “long-reining”) is a groundwork technique where a handler works a horse from behind or to the side using two long reins attached to the bit or a training cavesson. Unlike lunging, which moves the horse in circles on a single line, long lining gives the handler independent control of both sides of the horse’s body. This allows steering, bending, and transitions that closely mimic what a rider does from the saddle.
The technique serves several purposes. It lets a trainer see the horse’s movement from the ground, making it easier to spot problems like a hind leg that isn’t stepping far enough underneath the body or stiffness through the ribcage. It also builds strength in the horse’s back and abdominal muscles without the added challenge of carrying a rider’s weight. For young or rehabilitating horses, this is especially valuable: they learn to engage their core, balance, and respond to rein cues before anyone gets on. Once a horse develops these skills on the long lines, the transition to ridden work tends to go more smoothly for both horse and rider.
Long lining also gives trainers clearer feedback on their own communication. You can see in real time how your body position, energy level, and rein signals affect the horse’s response, and adjust accordingly. That visibility is harder to get from the saddle.
Safety When Long Lining a Horse
Working behind a horse with long reins introduces risks that basic leading doesn’t. Horses have a blind spot directly behind them and can kick or bolt if startled. The general principles of safe horse handling apply with extra emphasis here: never wrap the lines around your hands, keep excess line from dragging on the ground where it could tangle in your legs or the horse’s, and stay aware of the horse’s body language at all times.
When you’re positioned behind the horse, you’re relying on the reins and your voice for communication rather than direct eye contact. Starting in an enclosed arena, working with a calm horse, and building up gradually from simple straight lines to more complex figures all reduce the chance of things going wrong. Many trainers recommend learning the technique under the guidance of an experienced instructor before attempting it solo, since the coordination of two reins, your position, and the horse’s movement takes practice to manage safely.