Commission's May 2001 Meeting-Snook Management Options

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TO: Participants of the Charlotte Harbor Snook Guides meeting and Others

FROM: Bob Muller and Stu Kennedy, Florida Marine Research Institute

The attached PDF file contains the evaluation of several options for snook regulations on the gulf coast that were raised by the guides and anglers at the Mote Marine Laboratory meeting back in January. The possible management options identified during the meeting included changing the slot limit by either increasing the minimum size or moving the slot to a higher size range, closing February or May, decreasing the bag limit to one fish, and lastly closing the entire fishery to nothing but hook and release for several years. We decided to report the output from these analyses in percentage changes from the current regulations rather than changes in SPR values to simplify trends and interpretation.

The trends shown by the output for each option were predictable; the stock will improve. Each of these options were calculated for the gulf coast only. No attempt was made to examine the possible impact of these regulations on east coast snook due to effort shifting. The importance of the analyses was to quantify the magnitude of those changes and thereby compare options. For example:

• If the minimum size is raised by one inch (to 27") while keeping the maximum at 34", the numbers of trophy fish are expected to increase by 28%; however, the tradeoff is that the number of legal fish are expected to drop by 17% due to the narrower slot.
• If the slot width is kept the same (8") but moved up the scale to larger sized fish (28-36"), the result is a 23% reduction in legal fish because there will always be fewer larger fish than smaller fish and only a 13% gain in trophy fish because there are fewer sizes left in the trophy category.
• Closing February has very little impact because anglers aren't keeping many fish then but closing May increases the number of legal fish by 10% and increases the number of trophy fish by 44% because it removes fishing pressure at a time when snook are schooling and more vulnerable.
• Decreasing the bag limit to one fish increases legal fish by 6% and trophy fish by 20% by decreasing harvest in the slot.

There are other options that either expand or combine these basic options (please see Table 1 in the report) but the basic concepts still hold. Changing the slot width or position produces large increases in trophy fish but at the expense of the availability of legal fish, while combinations of seasonal closure and/or bag limits causes a lesser improvement in trophy fish but without the impact to legal fish.

The impact of total closure is not intuitively obvious. During the period of the closure, the numbers of legal and trophy fish increase dramatically. However, when the harvest fishery is reopened, the numbers of legal and trophy fish slowly decline, eventually reaching the same level that there would have been without a closure. Figures 3 and 4 from the report clearly show this concept. Legal fish rapidly return to the base level after reopening while trophy fish, subjected to only hook and release fishing, decline much less rapidly but still wind up at the same place. The only benefit a closure seems to have is head-starting the snook population if new regulations are implemented before the harvest fishery is reopened. Once the fishery is opened, abundance levels would still revert to what they would be at the new reduced fishing levels but they would get there faster.

The eye-opener in the analysis is how fast Florida's human population is increasing with a direct correlation between human population and resident Saltwater Fishing license sales, 20% over the past decade. The proportion of residents that also buy snook stamps has doubled in the past decade; more people means even more fishing mortality. The analyses in the current report takes this trend into account as it relates to fishing pressure but not the overall human impact to the environment, habitat, freshwater inflow and estuarine water quality. We do not yet have the ability to model those changes into fishery stock assessments but the obvious direction of change will be to decrease the number of snook available and force the implementation of new management measures in an attempt to keep up.

Prior to July 1, 2004, the Fish and Wildlife Research Institute was known as the Florida Marine Research Institute. The institute name has not been changed in historical articles and articles that directly reference work done by the Florida Marine Research Institute.