8. CONCLUSIONS AND RECOMMENDATIONS

• Mortality of endangered/critically endangered marine turtles within seismic tail buoys is under-reported by seismic personnel but based on anecdotal evidence it apparently occurs in warm and tropical waters worldwide

• This mortality could be readily addressed and reduced/eliminated by the seismic survey industry

• The long-term solution to the issue is to modify the design of tail buoys to eliminate the potential for turtle mortality, or for those seismic contractors whose tail buoys are known to cause turtle mortality to adopt the 'turtle friendly' tail buoy designs already used by other contractors

• In the shorter-term, 'turtle guards' of a combined Deflector and Exclusion design should be fitted to existing tail buoys to reduce turtle mortality.  Evidence to date suggests that the simple Exclusion designs implemented so far by certain seismic contractors are not effective in preventing turtle mortality

• It is important to assess the relative effectiveness of different turtle guard designs via scientific study, field trials and implementation of an industry-wide feedback report system

• The implementation of both 'turtle guards' and 'turtle-friendly' tail buoy designs should be adopted as HSE 'best practice' whenever seismic surveys are operating in warm/tropical water regions, including by the licensing bodies, seismic contractors and oil & gas companies

• Contractors and oil & gas companies should provide incentives to seismic crews and to tail buoy manufacturers to improve the design of turtle guards and tail buoys and to develop other potential solutions to the problem

• Open reporting of turtle entrapment by seismic crews should be strongly encouraged by seismic contractors and oil & gas companies in order to better document the scale and mechanism of turtle entrapment and to develop effective solutions

9. ACKNOWLEDGEMENTS

The information presented on these pages is the result of consultation with many seismic personnel over the 2007-2009 period, including gun mechanics, seismic observers, navigators, boat drivers, party chiefs, client representatives, marine mammal observers, oil companies and seismic contractors.  Sincere gratitude is owed to each and every one of them for their input, for allowing the use of their images and for providing their advice and ideas for potential practical solutions. 

10. REFERENCES AND FURTHER INFORMATION

• de Gurjão, L.M., Jde Freitas, J.E.P. and Araújo, D.S. (2005).  Observations of marine turtles during seismic surveys off Bahia, Northeastern Brazil.  Marine Turtle Newsletter, 108: 8-9.

• Ketos Ecology (2009). 'Turtle guards': A method to reduce the marine turtle mortality occurring in certain seismic survey equipment.  Ketos Ecology report, 14 pp.  Download here (820 Kb).

• Pierpoint, C. and Fisher, P. (2003). Observations of marine mammals, marine turtles and seabirds recorded during a 3D seismic survey east of the Canary Islands for Repsol YPF.  Unpublished Report, RPS Energy, Woking, 36 pp & appendices.

• Weir, C.R., Ron, T., Morais, M. and Duarte, A.D.C. (2007). Nesting and pelagic distribution of marine turtles in Angola, West Africa, 2000-2006: occurrence, threats and conservation implications. Oryx, 41: 224-231.  Download here (225 Kb).

• Weir, C.R. (2007). Observations of marine turtles in relation to seismic airgun sound off Angola. Marine Turtle Newsletter, 116: 17-20. Download here (1.3 Mb).

   

Feedback on this issue and suggestions for further developments for turtle guards would be greatly welcomed.  To provide feedback or for more information please contact Caroline Weir.