Northwest Fisheries Science Center

Selective Harvest Calculator (SHC)


The Selective Harvest Calculator (SHC) is a computer program for exploring the consequences of mark-selective harvest management strategies. In mark selective harvests (as they have been implemented for Pacific salmon), hatchery produced fish are given an external mark (adipose fin clip in the case of salmon) and only marked fish are supposed to be retained for harvest. The idea is to reduce mortality on wild fish while harvesting hatchery fish. The SHC simulates the progression of a mark-selective harvest starting with an initial pool of fish with three components: 1) wild fish (all unmarked), 2) marked hatchery fish, and 3) unmarked hatchery fish. The simulation proceeds with sequential encounters of individual fish with the fishing gear. Once fish encounter the gear, several fates are possible, including landing by the fishery or "hooking mortality" for unmarked fish that were released. At the end of the simulation, the fate of all the fish in the initial pool is evaluated to explore overall impacts of the fishery on the different components of the population.


The Selective Harvest Calculator was developed by Paul McElhany at the NOAA Northwest Fisheries Science Center


The Selective Harvest Calculator application is available free to the public. Source code (java) is available on request. The software was created by NOAA employees and is not subject to copyright protection. The program uses several open source libraries, which are used in accordance with their individual licenses.


The application is still in development and feedback feedback is appreciated. The download is a zip file containing the program, a user’s guide and two example input files. The program is an executable ".jar" file — just double click the selectiveHarvest.jar file to start the program. As described in the disclaimer, we do not make any guarantees about the suitability of SHC for any particular application.

Current Version - 1.0.5b 11/24/2009

Selective Harvest Calculator

Prior Versions

note: SHC is standalone application developed in Java and requires JRE version 6. If java is not already on your computer, it is available free at


The program is still in development and we appreciate feedback to make it better. Send any comments, questions or bug reports to