Evaluang The Potenal For A Sex-Balanced Harvest Approach In The Recreaonal Summer Flounder Jason Morson, Daphne Munroe, Ryan Harner, and Rachel Marshall Haskin Shellfish Research Laboratory, Rutgers University Background Objecves Results

1 95% of Landings in the Summer Flounder 600 1.0 Cape May, NJ A 100 0.8 Recreaonal Fishery are Female A Male 0.9 100% Female 0.6 500 -31% 90% 0.8 50 Proportion Female 0.4 80% ? Male 0.7 0.2 400 70% 1232 MORSON ET AL. Female 0 0 Berkeley et al. 2004; Birkeland and Dayton 2005; Hixon et al. (eight trips), New Jersey; Captree (nine trips) and Montauk 0.6 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 60% 2013; Shelton et al. 2015; Stige et al. 2017). (10 trips), New York; and Point Judith, Rhode Island (six Slots limits offer an alternative management approach to tradi- trips; Figure 1). The total length of every Summer Flounder Proportion Female 1 50% tional minimum size limits in that they restrict landings to some 300caught, whether landed or discarded, on each trip was 0.5 B intermediate range of sizes while large and small fish are released measured. In addition, the sex for all landed Summer Atlanc Highlands, NJ (Gwinn et al. 2013). In the Summer Flounder recreational fishery, Flounder was recorded. Since Summer Flounder must be 100 -58% 0.8 40% it was previously demonstrated thatslotlimitshavethepotentialtoFrequency dissected to determine sex, 10 discarded fish were also

% Female 0.4 increase landings in numbers under a fixed fishing exploitation rate sacrificed within predetermined fish length and water 0.6 30% Commercial Fishery by weight (Bochenek et al. 2010;Powelletal.2010). If smaller 200depth bins on each sampling trip (Table 1). A sex ratio— Proportion Female males are vulnerable to recreational fishing effort, a similar by depth bin, length bin, and trip—was applied to any 0.3 approach that redirects some fraction of the fishing mortality unsexed discarded fish to assign sex to the entire discarded 50 0.4 20% Recreaonal Fishery toward smaller-sized fish may also balance the fishing mortality portion of the catch (Table 1). with respect to sex. However, the only information available on the Analysis.—To estimate the effect of different slot limits on 10% sex composition of the Summer Flounder recreational catch comes three performance metrics—the total number of dead fish 0.2 0.2 from fish that were landed and are therefore larger than the mini- 100(landings + dead ), the of dead females, mum size limit (Morson et al. 2012, 2015). Without an estimate of and the ratio of dead discards to total number dead—we 0 0 0% the sex composition for fish below the , it is simulated outcomes from 21 potential slot limits. The 0.1 not possible to evaluate the sex-specificoutcomesofsuchalter- smallest lower size limit evaluated was 14 in (the minimum 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 35 45 55 65 75 native management options. size limit in the commercial fishery), and the largest upper Here we evaluate the potential for slot limits to produce a size0 limit evaluated was 21 in (the largest minimum size ever 0.0 1 sex-balanced harvest in the recreational Summer Flounder implemented in the recreational Summer Flounder fishery). Length (cm) 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 CCaptree, NY fishery. To estimate the size- and sex-specific vulnerability, The width of the slot limits varied from a minimum width of 100 0.8 we sampled all landed and discarded fish caught by recrea- 2intoamaximumwidthof7in. Total Length (inches) • Sex-selective harvesting can alter sex ratio and tional anglers on select party boats from New Jersey to Rhode A slot limit can be defined several ways, but here we are Island during the 2016 recreational fishing season. We then referring to a regulation where only fish within a minimum -21% 0.6 examined the performance of a wide array of slot limits to 500and maximum size limit could be kept, while all fish that are 1.0 negatively affect stock productivity. estimate which would have promoted a more sex-balanced greater thanB the maximum size or less than the minimum size 50 • Collect representative sex and length composition dataharvest while maintaining a fixed fishing mortality given the must be discarded. Since we did not record catch rate per 0.4 observed catch composition. 450angler and therefore could not evaluate alternative bag limits 0.9 within a given slot limit, all fish between the minimum reten-

Frequency 0.2 from the recreational summer flounder catch (landings tion size and maximum retention size of a slot limit were 400assumed to be kept (no bag limit). Each slot limit was imposed 0.8 • The influence alternative management actions could METHODS Male on the observed catch and catch composition data overall as ProportionFemale and discards). Field program.—Data collection focused on three states: New 0 0 well as by location and depth category, assuming effort was Jersey, New York, and Rhode Island; and one fishing mode: for- 350 0.7 have on the sex composition of the recreational catch fixed at what was observed. Finally, 10% mortality was 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 hire mode. In 2016, these states accounted for 82% of the total applied to all discarded fish in conformity with the recreational Female catch by state; however, the for-hire fishing mode accounted for cannot be evaluated because no information is available 300discard mortality rate currently applied in the Summer 0.6 1 only 5% of the total catch by mode. While the for-hire mode

Downloaded by [Jason M. Morson] at 06:13 24 October 2017 Flounder (Terceiro 2016). D • Determine whether slot limits have the potential toaccounted for only a small fraction of the total catch, the private 150 Montauk, NY To convert observed individual fish lengths (in) to esti- Proportion Female -55% on the sex composition of discarded summer flounder in mode, which accounted for 89%, operated across a similar spatial 250 0.5 0.8 mated individual fish weights (lb), we applied sex-specific scale. In 2016, 34% and 31% of the total catch in the for-hire and achieve a more sex-balanced recreational harvest. parameters from Morse (1981) for the equation this fishery. private modes, respectively, came from open ocean waters less 0.6 than or equal to 3 mi from the coast. In the same year, 42% and 200 0.4 100 wl αlβ: 54% of the total catch in the for-hire and private modes, ðÞ¼ respectively, came from inland waters (National Marine 150 0.3 Proportion Female 0.4 Service [NMFS], Fisheries Statistics Division, personalTotal Weight (pounds) The total number dead Nd for each simulated slot limit s was 50 communication). Given the two fishing modes access the same calculated as areas, data collection focused on the for-hire mode. The larger, for- 100 0.2 0.2 hire vessels had space for up to 75 anglers, which significantly Nd NL 0:10 ND ; Sampling Procedures increased the sample size potential on any one sampling trip. s ¼ s þ ðÞÂ s 0 0 Data collection spanned one entire recreational fishing 50 0.1 season from May 23, 2016, through September 16, 2016. where NL is the total number of fish that were landed, and ND 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 were collected bi-weekly aboard participating fishing is the0 total number of fish that were discarded. The biomass of 0.0 vessels from Cape May (eight trips) and Atlantic Highlands dead females, Fd, was calculated as 50 1 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 Pt. Judith, RI E -55% Total Length (inches) 40 0.8 Figure 1. Total number (A) and weight (B) of male and female summer flounder. 30 0.6 Solid line represents proporon female-at-length. Vercal dashed line represents 20 0.4 the 18-inch minimum size limit. 10 0.2

0 0 DEFENITIONS 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 Suitable Slot Limit = Any slot limit that resulted in a total number dead within +/- 10% of Total Length (inches) the observed total number dead (fixed fishing mortality). Figure 2. Total number of male and female summer flounder at each sampling Opmal Slot Limit = The Suitable Slot Limit that resulted in the largest reducon in dead locaon. Solid line represents proporon female-at-length. The opmal slot limit (see female biomass. definion) for each sampling locaon is represented by a shaded box. The change in dead female biomass going from an 18-inch size limit to this slot is indicated inside each box.

Female Gonad Male Gonad Table 1. Simulated slot limits and associated performance metrics for those slots that were deemed suitable and opmal at each sampling locaon. In parentheses next to each outcome is the proporonal change from the observed metric under an 18-inch minimum size limit to the metric calculated using the slot limit.

New Jersey New Jersey - Samples were collected on board for-hire recreational boats from late May through September, 2016. - The total length of all summer flounder caught on each sampling trip was recorded. - A subset of discarded fish from a range of fish lengths and water depths were sacrificed, retained on ice, and brought back to the lab to determine sex. Length- and depth-specific keys were developed from these fish and applied to sex all unsexed discards. - Sex of all landed fish was recorded on all sampling trips.

Analyses Simulaon of Slot Limits Performance Metrics

- Catch composion (number and weight at 1. Total Number of Dead Fish (landings + Conclusions Acknowledgements length by sex) was fixed at what was dead discards) - The applicaon of slot limits to the summer flounder recreaonal fishery has the potenal to simultaneously achieve mulple management objecves, We thank the captains and crews of the FVs Porgy IV, Bonanza II, Big Mohawk, including conservaon of female biomass under a fixed harvest rate. Fishermen, Laura Lee, Lazy Bones, and Gail Frances for perming us to collect observed. samples aboard their fishing vessels. We are grateful to Sarah Borse, Emerson Hasbrouck, Sco Curato-Wagemann, Tara Froelich, and Krisn Gerbino for - Slot limits evaluated ranged from 14 to 21 - The slot limits deemed suitable were all narrow, ranging from two to four inches wide, and oen contained the current minimum size limit within the slot 2. Biomass of Dead Females helping with data collecon. Eleanor Bochenek assisted with coordinang inches and varied in size from 2 to 7 inches limit. sampling trips, for which we are thankful. Paral funding for this work was provided by the Naonal Science Foundaon (NSF) Industry-University wide. 3. Rao of Dead Discards to Total Number - Opmal and suitable slot limits varied with sex and length composion at each sampling locaon. Cooperave Research Center Science Center for Marine Fisheries (SCeMFis) through membership fees under the direcon of the Industry Advisory Board; - All fish within a simulated slot limit were Dead - Given several assumpons inherent in the analysis (ex. fixed fishing effort under alternave slots, fixed catch composion), results should be viewed as SCeMFis administrave support is provided by NSF award number 1266057. deemed kept (no bag limit). opmal given the observed catch composion for the year, locaons, and modes sampled and further evaluaon of interannual, spaal, and mode-specific Addional funding was provided by the Save the Summer Flounder Fishery Fund dynamics is warranted. and the Jersey Coast Anglers Associaon.