This is of particular concern in recreational fisheries where the practice of catch and release is not prevalent. In addition to improving natural reproduction success the protected slot limit can also serve to improve the average catchable size of a protected species. The effort to increase the number of fish through natural reproduction mitigates the need for artificial stocking of a species to provide for a viable recreational fishery. With the size of the most sexually productive fish protected from harvest it is likely that an increased number will spawn during a given year and hence lead to more naturally produced individuals. The protected slot limit is set in such a way that it protects the size of those fish deemed most important to the species spawning success in that fishery. Protected slot limits are most often used to regulate the harvest from waters where natural reproduction of the concerned fish species occurs.

Generally, the purpose behind the implementation of protected slot limits is to improve the angling opportunities in a particular body or bodies of water. For example, a 'slot Red Drum' measuring between 18'-27' may be kept, but anything below may not be harvested, and any fish over 27' may only be harvested with a red drum tag 'Slot' may also refer to a fish within the size limits one can keep. Ī minimum landing size is a similar regulation in commercial fishing. Slot limits focus on protecting one segment of the life history which can influence overall fishing success. Slot limits are based on the principle that bass populations exhibit different habitat requirements during different phases of their lives. In this example largemouth bass shorter than 12 inches (30 cm) and longer than 16 inches (41 cm) may be removed from the water and kept for personal use in accordance with local fishing regulations.

For example, on a body of water where there is a protected slot limit on largemouth bass between 12 and 16 inches (30 and 41 cm), largemouth between those lengths may not be harvested. Usually set by state fish and game departments, the protected slot limit prohibits the harvest of fish where the lengths, measured from the snout to the end of the tail, fall within the protected interval. A slot limit is a tool used by fisheries managers to regulate the size of fish that can legally be harvested from particular bodies of water.

Fish game slot