Fishery policies have largely developed in response to current problems. One of the last policies to be implemented is individual transferable quotas, ITQs. This seems to be a promising policy instrument compared to those which have shown weaknesses. Extrapolating from previous experiences, however, a further investigation of the ITQ system may reveal weakness of this instrument as well, and may help improve the policy or stimulate the development of alternative policies. One such alternative may be auctioned seasonal quotas, ASQs. A laboratory experiment of a market with seven fishing firms is used to compare the two policies. Compared to traditional laboratory experiments, this experiment allows for dynamic adjustments of fishing capacities as well as quotas. Weaknesses and strengths are revealed, some of them surprising. For instance, having to pay variable prices ASQs may lead to less variation in equity than owning ITQs.