Longline Fishing Continues to Evolve
Longline fishing uses a mainline or groundline with numerous branch lines and hooks distributed along its length. Depending on the target species and fishing method, the gear may be operated near the surface, in midwater or close to the seabed.
Commercial longline fisheries are widely used for species including tuna, swordfish, halibut, sablefish and various groundfish. In bottom longline operations, the fishing line is positioned along the seabed, while pelagic longlines are designed to keep hooks at controlled depths in the water column.
Although the basic principle of longline fishing has remained relatively simple, modern commercial operations place greater emphasis on the relationship between gear construction, handling efficiency, durability and environmental performance.
Gear Selection Has a Direct Effect on Fishing Operations
For commercial vessels, longline gear is not simply a collection of individual components. The groundline, branch lines, hooks, swivels, floats and weights need to work together according to the vessel, target species and fishing conditions.
The groundline is particularly important because it carries the branch lines and transfers the load during setting and hauling. Its diameter, construction and material need to be selected according to the working load and fishing method.
Branch lines and leaders also require careful consideration. Their breaking strength, flexibility, abrasion resistance and connection method can affect both hook presentation and gear handling.
For this reason, commercial operators generally select line specifications according to actual fishing conditions rather than using one standard configuration for every fishery.
Bycatch Reduction Is Becoming More Important
Bycatch remains one of the main technical and management issues associated with longline fisheries. Seabirds, sharks, sea turtles and other non-target species can interact with longline gear, depending on the fishery and fishing area.
Fishing gear modifications can play an important role in reducing these interactions. NOAA research, for example, has documented cases where changing leader materials affected shark interactions while maintaining catches of target species.
Other approaches include changes to hook design, bait presentation, line weighting and setting practices. Recent NOAA-supported work is also evaluating Hookpod technology, which covers the point and barb of baited hooks during line setting to reduce seabird interactions.
These developments show that bycatch reduction is increasingly being approached through practical changes to fishing gear and operating methods, rather than relying only on changes in fishing effort.
Electronic Monitoring Is Expanding
Another important development is the increasing use of electronic monitoring in commercial fisheries.
Cameras and other monitoring equipment can record fishing operations, catch and discard information during gear retrieval. In Alaska, electronic monitoring is already used in several fixed-gear fisheries, including longline operations, to support catch monitoring and regulatory compliance.
For vessel operators, this means that fishing gear may increasingly need to be considered alongside monitoring requirements. Clear gear configuration, reliable connections and consistent handling can make fishing operations easier to document and manage.
The use of electronic logbooks is also expanding in some commercial hook-and-line fisheries. NOAA reports that electronic logbooks are available for certain West Coast commercial hook-and-line operations, alongside traditional reporting methods.
Durable Materials Matter in Commercial Longline Fishing
Longline gear is exposed to repeated loading, abrasion, saltwater and mechanical handling. For vessels making frequent sets and hauls, line durability can have a direct effect on maintenance requirements and fishing efficiency.
Material selection therefore remains an important consideration.
PE and UHMWPE ropes can be used where low weight, high strength and resistance to repeated handling are important. Nylon remains widely used in applications where elasticity and traditional line characteristics are preferred. The appropriate material depends on the fishing method, line position and required mechanical properties.
The same principle applies to netting and other fishing gear. A specification that works well in one fishery may not be suitable for another because depth, seabed conditions, target species, vessel equipment and local regulations can all affect gear requirements.
The Direction of Commercial Longline Gear
The development of longline fishing gear is moving toward a more integrated approach.
Rather than focusing on a single product, commercial fishermen and gear suppliers are increasingly considering the complete fishing system-from the mainline and branch lines to hooks, floats, weights, connections and monitoring requirements.
The priorities are clear: reliable gear, efficient handling, appropriate strength, controlled hook placement and reduced unwanted catch.
For fishing gear manufacturers, this also means that product development needs to follow the practical requirements of different fisheries. Longline gear should be specified according to the target species, fishing depth, vessel operation and local regulations instead of applying one specification across all markets.
As commercial fisheries continue to adopt improved monitoring and bycatch mitigation measures, well-designed and properly specified longline components will remain an important part of efficient fishing operations.