Introduction Methods · an ichthyometer to determine fork length and total length. (Picture by...
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Distribution patterns of tarpon, Megalops atlanticus, using remote detection technology of passive internal transponders at Boquerón, Puerto Rico Introduction Methods Results Discussion This is the first study using the PIT tag technology and autonomous antennae to record tarpon movement patterns in the Boquerón Wildlife Refuge. The number of tagged tarpon (n=379) versus the recaptured individuals (n=15) suggests that the tarpon population in the BWR is larger than what we thought. The fishing stations with the most tagged tarpon were open areas in the inner lagoon and the main channel. The movement frequency by antennae shows a crepuscular behavior of tarpon . A low recapture percent demonstrates high movement through the main channel that connects with the Rincón lagoon , use of mangroves as a refuge for tarpon in the inner lagoon, and the effect that manipulation of the culverts has on fish movement. In order to establish management recommendations we need to better understand tarpon movement patterns and habitat use. To achieve this we must establish more antennae in order to record movements in-outside the BWR and the Rincón lagoon. Also to promote sport fishing inside the Refuge would result in higher education of anglers and the community. References Acknowledgements Setting up the antennae Mark and recapture Megalops atlanticus is an important specie in sport and game fishing. Few previous studies have been conducted in Puerto Rico using tarpon. In 1999, Zerbi et al. (1999) published work on juvenile tarpon, where they implanted tags on the dorsal fin base of juviniles ranging from 40 to 80 mm SL. Following this, in 2001, Zerbi et al. (2001) worked with otoliths from juvenile M. atlanticus at Boquerón Bay, Cabo Rojo, Puerto Rico. However, there still remains lack of information of tarpon’s spatial distribution. To better understand fish populations, scientists and managers need long-term monitoring systems that collect population data in all environmental conditions (Barbour et al. 2010). With this study we aim to determine the spatial distribution of tarpon in the BWR using remote detection technology of passive internal transponders(PIT) tags in order to develop appropriate management strategies. 0 5 10 15 20 25 30 35 Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Amount of individuals Total of individuals detected per antenna per month antenna 1 antenna 2 20% 12% 0% 15% 14% 35% 3% 0% 1% % tagged tarpon per station 1.1 1.2 1.3 3.1 3.2 3.3 4 5 6 Tagging Stations 81% 19% % tarpon registered in one antenna vs both antennae A1 or A2 A1+A2 Installation of autonomous circular culvert antennae. Antennae were installed during November 2011 (Picture by Andrew Barbour). The two antennae were installed in the main channel and nine fishing stations were located around the Refuge. The PIT tag is inserted through an incision on the left side of the body behind the pelvic fin. (Picture by Andrew Barbour). Measurements were taken with an ichthyometer to determine fork length and total length. (Picture by Isabel Martinez) Various fishing gears were used (rod, gillnet) (Picture by Andrew Barbour and Isabel Martinez) Three movement patterns were observed: ID 177840105 was tagged on Nov 11, 2011 at St. 1.1 and detected on Dec 30, 2011 by A2. This individual continued its movement between both antennae until Sep 2012 detected by A1; ID 178695338 was captured on Jan 3, 2012 at St. 1.1 and recaptured on Jul 26, 2012 at St. 3.3. (In this case culvert # 3 was opened on May 22, 2012 and let tarpon move from the main channel to the inner lagoon); ID 180981832 was tagged in the Rincón lagoon on Aug 25, 2012 and was detected the next day by A2. 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 1:00 2:00 3:00 4:00 5:00 6:00 7:00 8:00 9:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00 19:00 20:00 21:00 22:00 23:00 0:00 # of detections Movement frequency per antenna St1 St2 0 20 40 60 80 100 120 140 1.1 1.2 1.3 3.1 3.2 3.3 4 5 6 # individuals Station Tagged tarpon per station vs recaptured tarpon per station Tagged tarpon Recaptured From the total of tagged tarpon (n=379) St 1.1, 1.2, 3.1, 3.2 and 3.3 have more accessibility for fishing. However, St 1.1 and 1.2 had the more tarpon recapture (n=12) versus St. 3.2 (n=1) and St. 3.3 (n=2). The inner lagoon and the main channel (3.1, 3.2, 3.3, 1.1, 1.2) represent areas with higher percent of tagged tarpon. The other stations are mostly mangroves and open water areas that make fishing more difficult. We found a high percent of tarpon detected by one of the two antennae, and a low percent of tagged tarpon detected by both antennae. That means individuals movements between antennae are uncommon. Both antennae read more detections during May and August, and a peak in September from antenna 2. We observed a crepuscular movement in both antennae with some peaks in antenna 2 between 2pm to 5pm. José A. Vargas-Santiago¹, Héctor Ruiz¹, Michael Nemeth¹, Idelfonso Ruiz-Valentín², Andrew Barbour³, Michelle Schärer-Umpierre¹ and Daniel Mateos-Molina¹ ¹HJR Reefscaping P.O. Box 1126 Hormigueros, Puerto Rico 00660 ²Refugio de Vida Silvestre de Boquerón Departamento de Recursos Naturales y Ambientales P.O. Box 366147 San Juan, Puerto Rico 00936 ³School of Forest Resources and Conservation Program of Fisheries and Aquatic Sciences University of Florida 7922 NW 71 St. Gainesville Florida32653 USA Barbour, A. B., Adams, A. J., Behringer, D. C., Yess, T., & Wolfe, R. K. (2010). PIT Tag Antennae Arrays as Fishery Monitoring Tools in Tropical Environments. Proceedings of the 63th Gulf and Caribbean Fisheries Institute, (pp. 118-124). SanJuan, Puerto Rico. Zerbi, A., Aliaume, C., & Joyeux, J.-C. (2001). Growth of juvenile tarpon in Puerto Ricans Estuaries. Journal of Marine Science , 87-95. Zerbi, A., Aliaume, C., & Miller, J. M. (1999). A comparison between two tagging techniques with notes on juvenile tarpon ecology in Puerto Rico. Bulletin of Marine Science , 9-19. Antennae Time Contract number: 2011-000089 Sirena Montalvo-Katz and Jose L. Carlo
Transcript of Introduction Methods · an ichthyometer to determine fork length and total length. (Picture by...
Distribution patterns of tarpon, Megalops atlanticus, using remote detection technology of passive internal transponders at Boquerón, Puerto Rico
Introduction Methods
Results
Discussion
This is the first study using the PIT tag technology and autonomous antennae to record tarpon movement patterns in the Boquerón Wildlife Refuge. The number of taggedtarpon (n=379) versus the recaptured individuals (n=15) suggests that the tarpon population in the BWR is larger than what we thought. The fishing stations with the mosttagged tarpon were open areas in the inner lagoon and the main channel. The movement frequency by antennae shows a crepuscular behavior of tarpon . A low recapturepercent demonstrates high movement through the main channel that connects with the Rincón lagoon , use of mangroves as a refuge for tarpon in the inner lagoon, and theeffect that manipulation of the culverts has on fish movement. In order to establish management recommendations we need to better understand tarpon movement patternsand habitat use. To achieve this we must establish more antennae in order to record movements in-outside the BWR and the Rincón lagoon. Also to promote sport fishinginside the Refuge would result in higher education of anglers and the community.
References Acknowledgements
Setting up the antennae Mark and recaptureMegalops atlanticus is an important speciein sport and game fishing. Few previousstudies have been conducted in Puerto Ricousing tarpon. In 1999, Zerbi et al. (1999)published work on juvenile tarpon, wherethey implanted tags on the dorsal fin baseof juviniles ranging from 40 to 80 mm SL.Following this, in 2001, Zerbi et al. (2001)worked with otoliths from juvenile M.atlanticus at Boquerón Bay, Cabo Rojo,Puerto Rico. However, there still remainslack of information of tarpon’s spatialdistribution. To better understand fishpopulations, scientists and managers needlong-term monitoring systems that collectpopulation data in all environmentalconditions (Barbour et al. 2010). With thisstudy we aim to determine the spatialdistribution of tarpon in the BWR usingremote detection technology of passiveinternal transponders(PIT) tags in order todevelop appropriate managementstrategies.
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Tagging Stations
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% tarpon registered in one antenna vs both antennae
A1 or A2 A1+A2
Installation of autonomous circular culvert antennae.
Antennae were installed during November 2011 (Picture by Andrew
Barbour).
The two antennae were installed in the main channel and nine fishing stations
were located around the Refuge.
The PIT tag is inserted through an incision on the left side of the
body behind the pelvic fin. (Picture by Andrew Barbour).
Measurements were taken with an ichthyometer to determine fork length and total length. (Picture by Isabel Martinez)
Various fishing gears were used (rod, gillnet) (Picture by Andrew Barbour and Isabel Martinez)
Three movement patterns were observed: ID 177840105 was tagged on Nov 11, 2011 at St. 1.1and detected on Dec 30, 2011 by A2. This individual continued its movement between bothantennae until Sep 2012 detected by A1; ID 178695338 was captured on Jan 3, 2012 at St. 1.1 andrecaptured on Jul 26, 2012 at St. 3.3. (In this case culvert # 3 was opened on May 22, 2012 and lettarpon move from the main channel to the inner lagoon); ID 180981832 was tagged in the Rincónlagoon on Aug 25, 2012 and was detected the next day by A2.
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Tagged tarpon
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From the total of tagged tarpon (n=379) St 1.1, 1.2, 3.1, 3.2 and 3.3 have more accessibility forfishing. However, St 1.1 and 1.2 had the more tarpon recapture (n=12) versus St. 3.2 (n=1) and St.3.3 (n=2).
The inner lagoon and the main channel (3.1, 3.2, 3.3, 1.1,1.2) represent areas with higher percent of tagged tarpon.The other stations are mostly mangroves and open waterareas that make fishing more difficult.
We found a high percent of tarpon detected by one of thetwo antennae, and a low percent of tagged tarpondetected by both antennae. That means individualsmovements between antennae are uncommon.
Both antennae read more detections during May and August, and a peak inSeptember from antenna 2.
We observed a crepuscular movement in both antennae with some peaks inantenna 2 between 2pm to 5pm.
José A. Vargas-Santiago¹, Héctor Ruiz¹, Michael Nemeth¹, Idelfonso Ruiz-Valentín², Andrew Barbour³, Michelle Schärer-Umpierre¹ and Daniel Mateos-Molina¹¹HJR Reefscaping P.O. Box 1126 Hormigueros, Puerto Rico 00660
²Refugio de Vida Silvestre de Boquerón Departamento de Recursos Naturales y Ambientales P.O. Box 366147 San Juan, Puerto Rico 00936 ³School of Forest Resources and Conservation Program of Fisheries and Aquatic Sciences University of Florida 7922 NW 71 St. Gainesville Florida32653 USA
Barbour, A. B., Adams, A. J., Behringer, D. C., Yess, T., & Wolfe, R. K. (2010). PIT Tag Antennae Arrays as Fishery Monitoring Tools in TropicalEnvironments. Proceedings of the 63th Gulf and Caribbean Fisheries Institute, (pp. 118-124). SanJuan, Puerto Rico.
Zerbi, A., Aliaume, C., & Joyeux, J.-C. (2001). Growth of juvenile tarpon in Puerto Ricans Estuaries. Journal of Marine Science , 87-95.
Zerbi, A., Aliaume, C., & Miller, J. M. (1999). A comparison between two tagging techniques with notes on juvenile tarpon ecology in PuertoRico. Bulletin of Marine Science , 9-19.
Antennae
Time
Contract number: 2011-000089
Sirena Montalvo-Katz and Jose L. Carlo
