1 Supporting Information 2 Movements of subadult and adult female lemon sharks in Florida and The Bahamas 3 Fig. 1 provides a synthesis of tag-recapture on the long distance movements of 4 subadult and adult female lemon sharks in Florida and The Bahamas compiled from the 5 National Marine Fisheries Cooperative Tagging Program (NMFS-CTP) database, some 6 of which has already been published elsewhere. We supplemented this with unpublished 7 information on the movements of adult female lemon sharks fitted with internal acoustic 8 transmitters and remotely tracked using passive acoustic telemetry. Here, we provide 9 additional details of this ongoing study. 10 Adult lemon sharks were targeted at Jupiter, Florida, one of the few known places 11 in the region where this life-stage occurs in large, predictable aggregations. Individuals 12 were captured at ca 25-30 m depth in the winter months (January to March) from 2005 to 13 2009. Sharks were collected using drift lines with single baited 20/0 circle hooks. All 14 sharks were fitted with a coded acoustic transmitter (Vemco® V16H) internally implanted 15 into the coelom. Nominal battery life for the tags was 84 months. Intervals for the coded 16 signals were randomized between 90 and 360 seconds. All sharks were released after the 17 hook was removed, with a typical at-vessel handling time of less than 15 minutes. Long- 18 range movements of sharks carrying acoustic transmitters were determined from 19 transmitter detection strings on underwater Vemco receivers that were deployed by us 20 and others. Approximately 165 Vemco acoustic receivers are deployed by the Florida 21 Atlantic Cooperative Tracking (FACT) research group, spanning a total of 310 km of 22 coastline between Delray Beach and Cape Canaveral. The Atlantic Coastal Telemetry 23 (ACT) array research group has approximately 1,000 monitors deployed in various 24 locations along the U.S. eastern seaboard north of the FACT array (pers. comm. 25 Dewayne Fox – ACT coordinator). Long distance movements were also detected through 26 tag returns from commercial fishing operations. 27 Lemon sharks fitted with acoustic transmitters at Jupiter were detected on local 28 receivers for a few months after tagging, after which they all dispersed from the local 29 area. After correcting for two sharks known to have been killed by fishermen within a 30 year of tagging, 33 of 41 individuals (80.5%) returned to the tagging site in subsequent 31 years (Supplementary Table 1). Sharks were detected on receivers or captured by 32 fishermen hundreds of kilometers away along the U.S. coast, ranging from the Dry 33 Tortugas, Florida (dispersal distance from tagging site ~ 515 km) to the Santee River 34 Mouth, South Carolina (~ 720 km from tagging site, Fig. 1). Sharks were also detected on 35 receivers deployed in Altamaha Sound Georgia, (~ 515 km, Fig. 1) and Cape Canaveral, 36 Florida, (~ 225 km, Fig. 1). All of these movements represent minimum dispersal given 37 that the majority of the coast, especially south of Jupiter, is not under receiver 38 surveillance. The average dispersal of adult females was 299.8 km and ranged from 225 39 km to 715 km. 40 41 42 43 44 45 Supplementary Table 1. Maximum-recorded dispersal distances (km) and years of return to tagging site for adult lemon sharks fitted 46 with acoustic transmitters and acoustic transmitters off Jupiter, Florida. “Max distance recorded” is the coastal distance between the 47 shark’s tagging location off Jupiter and either (a) a receiver it was detected on (“Acoustic detection” under “Detection type and shark 48 fate”), (b) a location provided by a fishermen who caught the shark (“Tag return”) and either harvested the animal or released it alive 49 or (c) from the pop-off location of a pop-off satellite archival tag (PSAT). “Return years” refers to winter periods (January to April) 50 when the individual was detected by receivers off Jupiter, indicative of philopatry. 51 52 Shark ID 34 36 2140 2141 2143 2145 2146 2147 2148 2151 7949 7950 Date tagged Total length (cm) Sex 23-Feb-07 24-Feb-07 27-Feb-07 254 255 236 M M M 5-Feb-08 26-Feb-07 8-Feb-08 15-Feb-08 9-Feb-08 15-Feb-08 9-Feb-08 22-Feb-08 26-Feb-08 251 245 231 237 231 232 238 248 268 M M M M M M M M F Max distance recorded (km) 2008 720 512 512 720 275 225 915 505 512 607 512 715 Y Y Y N/A N N/A N/A N/A N/A N/A N/A N/A Return years 2009 2010 Y Y Y N N Y Y Y Y Y Y Y N/A N/A N/A N N/A Y Y N N Y N Y 2011 Detection type and shark fate N/A N/A N/A N/A N/A N/A N N/A N/A N/A N N Acoustic detection Acoustic detection Acoustic detection Acoustic detection Tag return released Acoustic detection Tag return released Acoustic detection Acoustic detection Tag return released Acoustic detection Acoustic detection 7955 7956 7959 7960 7961 7966 7967 13038 52494 52993 52994 52995 55114 55115 55116 55121 55122 55123 55124 55125 55126 55127 63424 63425 63427 63429 63430 63431 25-Feb-08 11-Mar-08 25-Feb-08 25-Feb-08 12-Mar-08 11-Mar-08 6-Sep-08 6-Sep-08 8-Feb-12 22-Feb-09 22-Feb-09 8-Mar-09 21-Feb-09 14-Feb-09 21-Feb-09 21-Feb-09 21-Feb-09 21-Feb-09 22-Feb-09 14-Feb-09 21-Feb-09 13-Feb-09 1-Mar-10 1-Apr-10 29-Jan-10 20-Feb-10 1-Apr-10 1-Apr-10 229 255 242 262 235 263 257 257 240 265 280 274 247 242 240 247 276 279 293 255 242 260 260 264 284 245 260 237 F M M F F M M M M F F F F F M F F F F F M F F F F M F F 225 96 512 225 225 225 230 340 1020 518 225 225 225 715 225 225 225 225 225 225 225 500 225 225 225 505 225 225 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Y N Y Y Y Y Y Y N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Y N N N Y Y Y Y N/A Y Y Y N Y N Y Y Y Y Y Y Y N/A N/A N/A N/A N/A N/A N N N N N N N Y N/A Y Y N N Y N N N Y N Y N Y N N Y Y Y N Acoustic detection Sat Tag Acoustic detection Acoustic detection Acoustic detection Acoustic detection Tag return harvested Acoustic detection Acoustic detection Sat Tag Acoustic detection Acoustic detection Acoustic detection Acoustic detection Acoustic detection Tag return harvested Acoustic detection Acoustic detection Tag return harvested Acoustic detection Acoustic detection Tag return harvested Acoustic detection Tag return harvested Acoustic detection Acoustic detection Acoustic detection Acoustic detection 63433 63435 63436 63437 323622 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 29-Jan-10 23-Feb-10 19-Feb-10 28-Jan-10 26-Feb-08 266 280 220 278 265 F F F F M 225 225 225 225 230 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Y N Y y N/A Acoustic detection Acoustic detection Acoustic detection Acoustic detection Tag return harvested 75 How many of the tagged 1993-1998 sharks are likely to have survived to adulthood? 76 To put individual detections of natal philopatry in context it is useful to have 77 some understanding of how many of the females we tagged from 1995-1998 were 78 probably still alive in 2008-2012 and would have matured and had their first litters before 79 2012. Many parameters are needed to make such an estimate. We stress that what we 80 present is the only approximation that we can make with the available data, and it should 81 be viewed as providing a very general idea of likely number of survivors. 82 The probability of each tagged female surviving to have its first litter was 83 calculated by multiplying the annual survival rates for each year from when it was last 84 observed until the age of first reproduction, and excluding those that would have pupped 85 for the first time after 2012. The expected number of females to survive to pup was the 86 sum of these individual probabilities. A Monte Carlo simulation was used to estimate the 87 uncertainty in the estimate (Cortes 2002, Babcock et al. 2013). For Monte Carlo 88 simulation, each parameter (survival age 1-4, survival age 5+, age at reproduction) is 89 given a probability density function representing the uncertainty in the estimate; random 90 values of the three parameters are drawn from their probability density functions, and the 91 number of individuals that survive to pup is recalculated for each set of parameter values. 92 The 95% confidence interval of the number of survivors is calculated from the 2.5 and 93 97.5 percentiles of the distribution in estimated number of survivors. 94 The annual survival fraction from age 1-4 was drawn from a triangle distribution 95 between 0.43 and 0.85, corresponding to the range of survival values obtained during a 96 previous study of lemon sharks conducted at Bimini from 1995-2000 (DiBattista et al. 97 2007). The annual survival from age 4 and higher, after the sharks have left Bimini, was 98 drawn from a triangle distribution between 0.86 and 0.91, the same distribution used by 99 Cortes (2002), based on longevity data. The age at maturity was selected randomly with 100 equal probability from age 12, 13 and 14, so that the females would return to pup at age 101 13, 14 or 15. The smaller value is taken from previous studies (Brown and Gruber 1988); 102 the larger values reflect the fact that the females in this study made their first return at 103 later ages. For each of 10,000 Monte Carlo simulations, for each tagged shark, values of 104 survival between age 1-4, survival age 4+, and age at maturity were drawn. The survival 105 in each year, from the age when the shark was last captured (age 1 to 3) to its age at first 106 pupping were multiplied to produce a total survival probability for each shark. For some 107 individual sharks, the age at last capture was recorded as a range (e.g. 1-3), in which case 108 an age was drawn randomly with equal probability from ages 1, 2 and 3, for each of these 109 sharks in each Monte Carlo draw. The expected number of tagged females in each 110 simulation to survive to produce their first litter was the sum across all tagged sharks of 111 their survival probabilities, excluding those whose age at maturity implied that they 112 would have their first litter after 2012. The analyses were conducted in R, version 2.15.2 113 (Carnell 2011; R Core Team 2012). We enumerated juvenile females that were tagged in 114 Bimini from 1995-1998 that survived beyond the age of 2 years based on recapture 115 information (N=128). Monte Carlo simulations estimated that only 15 of these 116 individuals are likely to have survived to deliver their first litters up to 2012 (95% C.I.= 117 8-25). 118 Alternative nursery habitat 119 120 Lemon shark nursery habitat in the region is characterized as being shallow (< 1 m depth), close to shore, and occurring over sand and seagrass substrates, often near 121 mangroves (Morrissey and Gruber 1993; Gruber et al. 2001). We used the habitat-layered 122 map in The Bahamas GIS viewer (Mumby 2012) to calculate the percentage of available 123 coastline and near shore benthos with these characteristics within a 200 km radius of 124 Bimini, a conservative estimate of the dispersal range of adult female lemon sharks based 125 on compiled tagging and telemetry data above (Supplementary Table 1). Given this 126 dispersal range, GIS analysis suggests that Bimini constitutes ~ 2.4% of the nursery 127 habitat available to them, assuming that this entire potential nursery habitat is actually 128 used. As a preliminary assessment of lemon shark use of this potential nursery habitat we 129 conducted a hook-and-line survey in this habitat at two locations in Andros Island and 130 two locations in the Berry Islands from May 27-June 6, 2013. We observed large 131 numbers of juvenile lemon sharks in all four locations and captured 18 individuals < 90 132 cm TL in Andros and 11 in the Berry Islands (Supplementary Figure 1). These 133 preliminary validation efforts suggest that GIS analysis provides a useful approximation 134 of realized nursery habitat for lemon sharks within a 200 km radius of Bimini. Assuming 135 that the habitat we monitored at Bimini is 2.4% of the potential nursery habitat for 8-25 136 possible tagged returnees, then if female sharks chose nursery areas locations randomly 137 out of the available habitat the probability that an individual female would choose the 138 Bimini nursery would be 0.024. The probability of six or more of the surviving 8-25 139 Bimini females giving birth at Bimini under the null hypothesis of randomly choosing 140 nursery habitat would be less than 0.0001 (calculated from the binomial distribution with 141 probability 0.024 and sample size 8-25). 142 143 Supplementary Figure 1: Islands with lemon shark nursery habitat on the Great Bahama 144 Bank, Bahamas. Areas in yellow boxes on left panel are shown on the upper right (Berry 145 Islands) and lower right (Andros Island). Red boxes outline the area that was surveyed 146 for lemon sharks. Red circles show capture locations of juvenile lemon sharks (< 90 cm 147 TL) at each site (N = 11 at the Berry Islands; N= 18 at Andros). Size of circle is 148 proportional to the number of individuals captured at each site. 149 150 151 152 References Babcock EA, Coleman R, Karnauskas M, Gibson J (in press) Length-based indicators of 153 fishery and ecosystem status: Glover’s Reef Marine Reserve, Belize. Fisheries 154 Research. 155 156 Brown CA, Gruber SH (1988) Age assessment of the lemon shark, Negaprion brevirostris, using tetracycline validated vertebral centra. Copeia, 3, 747-753. 157 158 159 Carnell R (2011) Triangle: Provides the standard distribution functions for the triangle distribution. R package. Cortes, E (2002) Incorporating uncertainty into demographic modeling: application to 160 shark populations and their conservation. 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