Sea Turtle Post-release Mortality Online Workshop - 2011


Conduct a scientific review to ensure that currently employed methods for estimating sea turtle post-release mortality in pelagic longline fisheries are made using best available science. 


Based on critiques of current methods used to estimate sea turtle post-release mortality rates in pelagic longline fisheries, provide suggestions to establish more reliable estimates.


Specifically, the group will:

1)    Review the post-release mortality estimates for sea turtles as currently defined in Table 1 (p.26) of Ryder et al. (2006);

2)    Identify relevant research conducted since the 2004 meeting described in Ryder et al. (2006);

3)    Review and critique research conducted since 2004 that is relevant for estimating post-release mortality probability;

4)  Discuss potential effects of hook design (J, tuna, circle) and size (narrowest width) on injury and mortality. 


WHEN: 15 and 16 November 2011, 11:30 am -4:00 pm EST


WHERE: Online - webinar - directions provided via email.

Download Ground rules


Since the time of the workshop in 2004, there have been a number of published papers as well as anecdotal information related to sea turtle post-release mortality, suggesting a benefit of reassessing estimates in light of new information.  In addition to anatomical hooking location and trailing gear, this meeting could also provide an opportunity to consider effects of hook types, such as circle, J, and Tuna hooks.


Day 1 - November 15

(Times are Eastern Standard Time)

11:30-11:40     Workshop ground rules (Yonat Swimmer)

11:40-11:45     Introduction (Sam Pooley)

                        1.  Background

11:40-11:55     1.1.  History of NMFS Activities Related to Estimates of Post-Release Mortality and Application 

                         of Estimates in Southeast U.S.  (Sheryan Epperly and Lesley Stokes)

                         DOWNLOAD presentation pdf

11:55-12:10     1.2.  NMFS applications of estimates of post-release mortality rates (Pat Opay)

                         DOWNLOAD presentation pdf

12:10-12:25     1.3.  Use of Ryder et al. estimates in BiOp (PIRO/Dawn Golden)

                         DOWNLOAD presentation pdf

12:25-12:45     1.4.  Questions, discussion

12:45-1:00       Break

1:00 -2:00        2.  New scientific information. (Mariluz Parga)

                        2.1.  Review table summarizing methods and findings of relevant publications.

                        DOWNLOAD Table summarizing methods and results of publications estimating sea turtle post-release survival probability 

                        2.2.  Questions, discussion.

2:00-2:15         Break

2:15-2:40         3.1.  Updates on Unpublished data 20 min presentation, 5 min for questions (Yonat Swimmer)

                        DOWNLOAD presentation pdf

2:40-3:05         3.2.  Updates on Unpublished data 15 min presentation, 10 min for questions (Chris Sasso and 

                                Mike James)

                         DOWNLOAD presentation pdf

3:05-3:30         4.  Estimation methods.  Discussion - expand the list of experimental methods to estimate sea 

                             turtle post-release mortality in longline fisheries, adding to the methods identified in the 

                             summary table (Eric Gilman) 

                         DOWNLOAD  background document: Review of methods to estimate sea turtle post-release 

                             mortality rates.

                         DOWNLOAD presentation pdf

3:30 – 4:00      5.  Questions, discussion, recap of Day 1, review Day 2 agenda (Yonat Swimmer)



Day 2 - November 16


11:30-11:40     Summary of Day 1 and review Day 2 agenda (Yonat Swimmer)

                        6.  Veterinary Perspectives. (Brian Stacy, DVM)

11:40-12:00     6.1.  Speaker: Brian Stacy, DVM.  15 min presentation, 5 min for questions

                        DOWNLOAD presentation pdf

12:00-12:20     6.2.  Speaker: Mariluz Parga, DVM.  15 min presentation, 5 min for questions

                        DOWNLOAD presentation pdf

12:20-12:45     6.3.  Discuss comments in Ryder et al. re: importance of gear removal, likelihood of death 

                                within 90 day, potential effects of hook design (J, tuna, circle) on injury and mortality, etc. 

                                (Brian Stacy)

Fish hook and line morbidity and mortality examples of cases seen in rehab. Terry Norton DOWNLOAD pdf of presentation

12:45-1:15       Break

1:15-2:15         7.1.  Discuss/critique assumptions and uncertainties in Ryder et al. 2006 (have they improved 

                                 since 2004?) (Chair: Jeanette Wyneken)

Discussion items:

A.  Ryder et al. 2006 separates hard shelled turtles from leatherbacks and apparently attributes higher rates of mortality to same level of injury. Does this seem reasonable based on best available science?

2:15-2:45         7.2.  What do we know now that we didn’t know in 2004 that might influence changes in 

                                 estimates in Ryder et al? (Chair: Dr. Molly Lutcavage)

Discussion items:

B.  Use of satellite telemetry data for interpretation of mortality:

B.1.  Is there a generally agreed upon preferred tag type (e.g., PSAT, PTT)?

B.2.  Can changes in dive behavior (eg depth or distance traveled) be used as a proxy for some effect 

     due to the interaction event (eg comparisons of dive behavior of turtle groups with diff. types of injury)

2:45-3:45         8.  Closing discussion and summary (Yonat Swimmer)

Discussion items:

C.  Discussion on revisiting current NMFS policy due to more recent best available science since 2004.

D.  Thoughts on future meetings.



Keith Bigelow, National Marine Fisheries Service,

Milani Chaloupka, Ecological Modeling Services,

Sheryan Epperly, National Marine Fisheries Service,

Joseph Flanagan, Houston Zoo,

Eric Gilman (co-organizer), Hawaii Pacific University,

Dawn Golden, National Marine Fisheries Service,

Martin Hall, Inter-American Tropical Tuna Commission,

Craig Harms, North Carolina State University,

Mike James, Fisheries and Oceans Canada,

Molly Lutcavage, Univ. Massachusetts,

Terry Norton, Georgia Sea Turtle Center,

Patrick Opay, National Marine Fisheries Service,

Mariluz Parga, SUBMOM,

Samuel Pooley, National Marine Fisheries Service,

Chris Sasso, National Marine Fisheries Service,

Barbara Schroeder, NMFS,

Brian Stacy, University of Florida,

Lesley Stokes, National Marine Fisheries Service,

Yonat Swimmer (lead organizer), National Marine Fisheries Service,

Jeanette Wyneken, Florida Atlantic University,


Adam Bailey, National Marine Fisheries Service,

Christina Fahy, National Marine Fisheries Service, 

Karen Frutchey, National Marine Fisheries Service,

Asuka Ishizaki, Western Pacific Fishery Management Council,

Irene Kinan-Kelly, National Marine Fisheries Service,

Chris Yates National Marine Fisheries Service,



Aguilar R, Mas J, Pastor X. 1995. Impact of Spanish swordfish longline fisheries on the loggerhead sea turtle Caretta caretta population in the Western Mediterranean.  In JI Richardson and TH Richardson, comps.  Proceedings of the 12th Annual Workshop on Sea Turtle Biology and Conservation, pp. 1-6, US Dept. Commerce NOAA Tech. Memo. NMFS-SEFSC-361. 


Email notes response to queries to R. Aguilar (2001) DOWNLOAD

Allen, L.  2004.  Memorandum to Samuel G. Pooley, Acting Regional Administrator, and Jeffrey Polovina, Acting Science Center Director.  Criteria for Estimating Post-hooking Mortality in Marine Turtles as a Result of Interactions with Longline Gear for Purposes of Conducting the February 2004 Section 7 Consultations on Pelagic Fisheries in the Pacific.  National Marine Fisheries Service. DOWNLOAD 

Balazs, G., Pooley, S., Murakawa, S.  1995.  Guidelines for Handling Marine Turtles Hooked or Entangled in the Hawaii Longline Fishery:  Results of an Expert Workshop Held in Honolulu, Hawaii March 15-17, 1995.  NOAA Technical Memorandum NOAA-TM-NMFS-SWFSC-222.  National Marine Fisheries Service, Southwest Fisheries Science Center, Honolulu Laboratory, Honolulu, Hawaii, USA.  DOWNLOAD

Bjorndal KA, Bolten AB, Lagueux CJ. 1994. Ingestion of marine debris by juvenile sea turtles in coastal Florida habitats. Marine Pollution Bulletin 28(3): 154–158. DOWNLOAD


Carruthers, E., Schneider, D., Neilson, J. 2009. Estimating the odds of survival and identifying mitigation opportunities for common bycatch in pelagic longline fisheries. Biological Conservation 142: 2620-2630. DOWNLOAD


Casale, P., Freggi, D., Rocco, M. 2008. Mortality induced by drifting longline hooks and branchlines in loggerhead sea turtles, estimated through observation in captivity. Aquatic Conservation: Marine and Freshwater Ecosystems 18: 945-954. DOWNLOAD


Chaloupka, M., Parker, D., Balazs, G. 2004. Modelling post-release mortality of loggerhead sea turtles exposed to the Hawaii-based pelagic longline fishery. Marine Ecology Progress Series 280: 285-293. DOWNLOAD


Chaloupka, M., Work, T., Balazs, G., Murakawa, S., Morris, R.  2008.  Cause-specific temporal and spatial trends in green sea turtle strandings in the Hawaiian Archipelago (1982-2003).  Marine Biology 154: 887-898.  DOWNLOAD


Epperly, S.  2011.  HMS Biological Opinion Mortality Ratio Requirement.  Memorandum to Bonnie Ponwith, Director, Southeast Fisheries Science Center.  National Marine Fisheries Service, Southeast Fisheries Science Center, Miami, Florida, USA.  DOWNLOAD


Epperly, S.P., Boggs, C. 2004. Post-hooking mortality in pelagic longline fisheries using "J" hooks and circle hooks. Application of new draft criteria to data from the Northeast Distant Experiments in the Atlantic. National Marine Fisheries Service, Protected Resources & Biodiversity Division,Internal Document Number PRD-03/04-04, 8p. DOWNLOAD

Epperly, S., Garrison, L., Stokes, L. 2009. Sea turtle bycatch reduction in the U.S. Atlantic Pelagic Longline Fishery-preliminary analysis. Presented to Advisory Board (of NMFS), February 17, 2009 and the 29th Annual Symposium on Sea Turtle Biology and Conservation, February 18, 2009, Brisbane, Australia, 27p. (Posted 2/2009).  Powerpoint presentation.

Fox, W., Knowles, D., Morehead, B.  2001.  Memorandum For William T. Hogarth, Acting Assistant Administrator for Fisheries.  Mortality of Sea Turtles in Pelagic Longline Fisheries – Decision Memorandum.  National Marine Fisheries Service, Sliver Spring, MD, USA.  DOWNLOAD

Hays, G. C., A. C. Broderick, B. J. Godley, P. Luschi, and W. J. Nichols. 2003. Satellite telemetry suggests high levels of fishing-induced mortality in marine turtles. Marine Ecology Progress Series 262:305–309.  DOWNLOAD


Mangel, J. et al. 2011. Post-capture movements of loggerhead turtles in the southeastern Pacific Ocean. Marine Ecology Progress Series 433: 261-272. DOWNLOAD

Moraes-Neto, M., et al.  2003.  Retrieval of an esophageal foreign body (fish hook) using esophagostomy in an olive Ridley turtle, Lepidochelys olivaceaJournal of Herpetological Medicine and Surgery 13: 26-28.  DOWNLOAD

Musyl, M., Domeier, M., Nasby-Lucas, N., Brill, R., McNaughton, L., Swimmer, J., Lutcavage, M., Wilson, S., Galuardi, B., Liddle, J.  2011.  Performance of pop-up satellite archival tags.  Marine Ecology Progress Service 433: 1-28. DOWNLOAD

NMFS.  2001.  Stock Assessment of Loggerhead and Leatherback Sea Turtles and an Assessment of the Impact of the Pelagic Longline Fishery on the Loggerhead and Leatherback Sea Turtles of the Western North Atlantic.  NOAA Technical Memorandum NMFS-SEFSC-455.  National Marine Fisheries Service, Southeast Fisheries Science Center.

NOTE:  Refer to (i) Appendix 4 (mislabeled Appendix 5) on pages 313-335; and (ii) Chapter 4 on pages 152-160.

NMFS.  2010. Sea Turtle Life History Form.  National Marine Fisheries Service.  DOWNLOAD

NMFS.  2010.  Careful release protocols for sea turtle release with minimal injury. NOAA Technical Memorandum NMFS-SEFSC-580.  National Marine Fisheries Service Southeast Fisheries Science Center. 2008, Revised 2010.  130p.  

Oros J, Calabuig P, Deniz S. 2004. Digestive pathology of sea turtles stranded in the Canary islands between 1993 and 2001. Veterinary Record 155(6): 169–174. 

Oros, J., Torrent, A., Calabuig, P., Deniz, S.  2005.  Diseases and causes of mortality among sea turtles stranded in the Canary Islands, Spain (1998-2001).  Diseases of Aquatic Organisms 63: 13-24. DOWNLOAD

Parker, D.M., Balazs, G.H., Murakawa, S.K.K., and Polovina, J.J. 2005. Post-hooking survival of loggerhead sea turtles taken by pelagic longline fishing in the North Pacific. In Proceedings of the twenty-first annual symposium on sea turtle biology and conservation. NOAA Technical Memorandum NMFS-SEFSC-528. Edited by M.S. Coyne and R.D. Clark. pp. 50-52.


Ryder, C., Conant, T., Schroeder, B. 2006. Report of the Workshop on Marine Turtle Longline Post-Interaction Mortality. Bethesda, Maryland, USA, 15-16 January, 2004. NOAA Technical Memorandum NMFS-OPR-29. National Marine Fisheries Service, Bethesda, Maryland, USA. DOWNLOAD


Sasso,C., Epperly, S. 2007. Survival of pelagic juvenile loggerhead turtles in the open ocean. Journal of Wildlife Management 71(6): 1830-1835. DOWNLOAD


Secretariat of the Pacific Community.  2009.  Longline terminal gear identification guide.  ISBN 978-982-00-0374-3.  DOWNLOAD

Southeast Fisheries Science Center. 2011. Protocols for categorizing sea turtles for post-release mortality estimates. NMFS Southeast Fisheries Science Center Contribution PRD-2011-07, August 17, 2011, 7p.  DOWNLOAD

Stokes, L. et al. 2011. Hook ingestion rates in loggerhead sea turtles Caretta caretta as a function of animal size, hook size, and bait. Endangered Species Research 14: doi:10.3354/esr00339.

Swimmer Y, Brill R, Musyl M (2002) Use of pop-up satellite archival tags to quantify mortality of marine turtles incidentally captured in longline fishing gear. Mar Turtle Newsl 97:3–7.  DOWNLOAD

Swimmer, Y., Arauz, R., McCracken, M., McNaughton, L., Ballestero, J., Musyl, M., Bigelow, K., Brill, R.  2006.  Diving behavior and delayed mortality of olive ridley sea turtles Lepidochelys olivacea after their release from longline fishing gear.  Marine Ecology Progress Services 323: 253-261. DOWNLOAD

Swimmer, Y., McNaughton, L., Foley, D., Moxey, L., Nielson, A.  2009.  Movements of olive ridley sea turtles Lepidochelys olivacea and associated oceanographic features as determined by improved light-based geolocation.  Endangered Species Research 10: 245-254. DOWNLOAD

Wilson, R.  2011.  The price tag.  Nature 469: 164-5. DOWNLOAD

Work and Balazs (2010) Pathology and distribution of sea turtles landed as bycatch in the Hawaii-based North Pacific pelagic longline fishery. J.Wild.Diseases, 46(2) 422-432. DOWNLOAD 

Kemp's ridley radiographs – examples of types of hooks and positions – provided by Joe Flanagan.

Examples of Mustad circle hook widths - download image