Short communicationLine cutter for use when releasing large marine organisms caught on longline gear

•An easily constructed line cutter is described for use with longline gear.•Line cutter severs leader in close proximity to hooking locations.•Use of line cutter does not require captured organism be brought to surface.•Design is readily modified for individual needs and applications.

Releasing large marine organisms captured on longline gear can often be difficult due to problems associated with the use of conventional line cutters. For example, struggling animals can remain below the water's surface for extended periods, thus providing limited access to the end of the leader nearest the hook. We describe a new line cutter design that outperforms conventional designs. The line cutter described herein can be deployed by a single individual and severs leader material in close proximity to the location of hooks while negating the need to bring the captured organism to the surface. The use of the line cutter reduces stress and potential injury to captured animals, is easily and inexpensively constructed, and has applications beyond its intended use, such as freeing lines snagged or entangled under vessels.