Gandy, R.L., Crowley, C.E., Leone, E.H., and Crawford, C.R. North American Journal of Fisheries Management
The experiment aimed to determine what size of cull ring would reduce the catch of pre-recruit stone crab (Menippe mercenaria) and other bycatch while maintaining legal-sized catch. Catch compositions of crabs from unmodified plastic commercial stone crab traps and traps fitted with three sizes of cull rings were compared in the stone crab fishery across Florida’s west coast. Traps outfitted with cull rings retained bigger crabs, had less bycatch, and fewer pre-recruit crabs, while yielding the same number of legal-sized crabs as traps without cull rings. A 55.6 mm cull ring was then distributed to commercial fishermen, who reported anecdotally that they liked the performance of the rings and felt that it would improve the efficiency of their operations.
https://afspubs.onlinelibrary.wiley.com/doi/abs/10.1002/nafm.10232