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A protected 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. 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.〔Minnesota Department of Natural Resources. “Minnesota Fishing Regulations 2011.” 2011. Print.〕 For example, on a body of water where there is a protected slot limit on largemouth bass between 12 and 16 inches, no largemouth bass greater than 12 inches and less than 16 inches may be harvested.〔“Connecticut’s Bass Management Lakes”. PDF. Accessed 9/25/2011. URL: http://www.cr.gov/dep/lib/dep/fishing/freshwater/bassbroc.pdf〕 In this example largemouth bass less than 12 inches and greater than 16 inches may be removed from the water and kept for personal use in accordance with local fishing regulations. Slot limits are based on the principle that bass populations exhibit different habitat requirements during different phases of their life histories. Slot limits focus on protecting one segment of the life history which can influence overall fishing success. A minimum landing size is a similar regulation in other areas. ==Purpose== Generally, the purpose behind the implementation of protected slot limits is to improve the angling opportunities in a particular body or bodies of water. Protected slot limits are most often used to regulate the harvest from waters where natural reproduction of the concerned fish species occurs. 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. 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 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. In addition to improving natural reproduction success the protected slot limit can also serve to improve the average catchable size of a protected species.〔Dokken, Brad. “Relaxed Walleye Slot Limit Draws Crowds on Upper Red Lake.” Northland Outdoors. June 28, 2009. Online Article. Accessed 9/25/2011. URL: http://www.northlandoutdoors.com/event/article/id/124436/publisher_ID/40/〕 This is of particular concern in recreational fisheries where the practice of catch and release is not prevalent. The slot limit protects those fish that evade harvest until their size exceeds that of the lower end of the protected slot. They are then protected from harvest until they exceed the maximum size within the protected slot. Fish within this size range are protected from harvest during the time when their size would make them desirable by anglers. In such a scenario the protection of large numbers of medium sized fish translates into a higher success rate of those that exceed the slot limit.〔Pierce, Rodney. Tomcko, Cynthia. “Initial Effects of Slot Length Limits for Northern Pike in Five North-Central Minnesota Lakes.” 1997. Online report. PDF. Accessed 9/25/2011. URL: http://files.dnr.state.mn.us/publications/fisheries/investigational_reports/454.pdf〕 Hence, the protected slot limit increases the amount of fish that reach the large sizes sought by sport anglers. Of course, this model assumes that the lake or stream in question contains a forage base suitable to support fish of this size. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「slot limit」の詳細全文を読む スポンサード リンク
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