Graeme Hays

Graeme C. Hays (born 1966) is a British and Australian marine ecologist known for his work with sea turtles and plankton. He is the Alfred Deakin Professor of Marine Science at Deakin University, Australia.

Graeme Clive Hays
Graeme Hays 2015.jpg
Hays at Deakin University in 2015
Alma mater
Known forResearch on sea turtles and plankton
AwardsAlfred Deakin Award
Scientific career
FieldsMarine ecology
Doctoral advisors

He was born in Nairobi, Kenya and works in the area of marine ecology researching animal movements and impacts of climate change. His work has helped reveal navigational abilities of sea turtles.,[1] the impact of global warming on sea turtles[2] and the factors controlling zooplankton diel vertical migration,[3] the largest animal migration on Earth.[4]

Hays has been named one of the most highly cited scientists in the field of marine biology.[5]


Hays gained a PhD in physiological ecology in 1991 under the mentorship of John Speakman FRS at the University of Aberdeen. He worked at the Sir Alister Hardy Foundation for Ocean Science and Bangor University, Wales before becoming a lecturer at Swansea University in 1996, becoming a Professor in 2005. He became Professor of Marine Science at Deakin University in Australia in 2013.

He served on numerous journal editorial boards and from 2005 to 2013 he was Executive Editor of the British Ecological Society's Journal of Animal Ecology.


In recognition of his research, he was made an Alfred Deakin Professor in 2014, the most prestigious honour that Deakin University bestows on its staff.[6]

According to the 2020 science-wide standardized citation indicator, developed by Stanford University academic John P.A. Ioannidis and colleagues, Hays was listed in the top 30 most cited marine biologists in the world.[5]

His research expedition to Ascension Island in 1997 for satellite tracking studies of green turtles to examine questions of turtle navigation first posed by Charles Darwin,[7] became the subject of a best-selling book Turtle Island: A Visit To Britain’s Oddest Colony by Sergio Ghione.[8]

Two first-day issues of postage stamps have been dedicated to his research on sea turtles.[9]

Research workEdit

Sea turtle satellite trackingEdit

In 1990 he conducted one of the first satellite tracking studies of sea turtles[10] and subsequently used this approach to assess their navigational abilities,[1][11] including at-sea experiments,[12] and to reveal how ocean currents affect movements and so influence migration patterns.[13]

Leading international review teams he has shown how satellite tracking can be widely used, across diverse animal taxa, to understand movement patterns and drive successful conservation outcomes for endangered species.[14][15]

His research has developed methods to assess how climate warming is affecting the temperature-dependent sex ratios of sea turtle hatchlings and the likely impacts of population feminisation.[2][16]

Recent research also shows how the long-distance movements of sea turtles can take them outside of even the largest marine reserves and into ocean areas with no protection from poaching or fishing gear entanglements,[17] raising conservation concerns.[18]

Plankton long-term changes and diel vertical migrationEdit

Hays’ research has provided some of the key evidence for understanding that predator-evasion underpins zooplankton diel vertical migrations,[5][19] which is the largest animal migration (by biomass) on the planet.

He has also showed how phytoplankton and zooplankton phenology, range changes and abundance are being dramatically altered by climate change including major shifts in species composition.[20][21]


Hays’ research has received media coverage including in Science,[22] Nature[23][24] and the Australian Broadcasting Corporation (ABC).[25]


  1. ^ a b Hays, G.C., Cerritelli, G., Esteban, N., Rattray, A., Luschi, P. (2020) "Open ocean reorientation and challenges of island finding by sea turtles during long-distance migration". Current Biology 30, 3236-3242.
  2. ^ a b Laloë, J.-O., Cozens, J., Renom, B., Taxonera, A., Hays, G.C. (2014) "Effects of rising temperature on the viability of an important sea turtle rookery". Nature Climate Change 4, 513-518
  3. ^ Hays, G.C., Kennedy, H., Frost, B.W. (2001) "Individual variability in diel vertical migration of a marine copepod: why some individuals remain at depth when others migrate". Limnology & Oceanography 46, 2050-2054
  4. ^ "Graeme C. Hays - Google Scholar Citations".
  5. ^ a b c Ioannidis, J.P.A., Boyack, K.W., Baas, J. (2020) "Updated science-wide author databases of standardized citation indicators". PLoS Biology 18 (10), e3000918.
  6. ^ "Alfred Deakin Professors". Retrieved 26 June 2021.
  7. ^ Darwin, Charles (1873) "Perception in the lower animals". "Nature" 7, 360 (13 March 1873).
  8. ^ Ghione, Sergio "Turtle Island: A Visit To Britain’s Oddest Colony", ISBN 0713995475.
  9. ^ "First day issue of stamps, British Indian Ocean Territory, 15th November 2016". Retrieved 26 June 2021.
  10. ^ Hays, G.C., Webb, P.I., Hayes, J.P., Priede, I.G., French, J. (1991) "Satellite tracking of a loggerhead turtle (Caretta caretta) in the Mediterranean". Journal of the Marine Biological Association of the UK 71, 743-746.
  11. ^ Hays, G.C., Åkesson, S., Broderick, A.C., Glen, F., Godley, B.J., Papi, F., Luschi, P. (2003) "Island-finding ability of marine turtles". Proceedings of the Royal Society of London B 270, S5-S7.
  12. ^ Sims, D.W. (2003) " News & Views - Homing is a breeze for sea turtles". Nature 423, 128.
  13. ^ Hays, G.C., Fossette, S., Katselidis, K.A., Mariani, P., Schofield, G. (2010) "Ontogenetic development of migration: Lagrangian drift trajectories suggest a new paradigm for sea turtles". Journal of Royal Society Interface 7, 1319-1327.
  14. ^ Hays GC, Ferreira LC, Sequeira AMM, Meekan MG, Duarte CM, Bailey H, Bailleul F, Bowen WD, Caley MJ, Costa DP, Eguíluz VM, Fossette S, Friedlaender AS, Gales N, Gleiss AC, Gunn J, Harcourt R, Hazen EL, Heithaus MR, Heupel M, Holland K, Horning M, Jonsen I, Kooyman GL, Lowe CG, Madsen PT, Marsh H, Phillips RA, Righton D, Ropert-Coudert Y, Sato K, Shaffer SA, Simpfendorfer CA, Sims DW, Skomal G, Takahashi A, Trathan PN, Wikelski M, Womble JN, Thums M. (2016) "Key questions in marine megafauna movement ecology". Trends in Ecology and Evolution 31, 463-475.
  15. ^ Hays GC, Bailey H, Bograd SJ, Bowen WD, Campagna C, Carmichael RH, Casale P, Chiaradia A, Costa DP, Cuevas E, de Bruyn PJN, Dias MP, Duarte CM, Dunn DC, Dutton PH, Esteban N, Friedlaender A, Goetz KT, Godley BJ, Halpin PN, Hamann M, Hammerschlag N, Harcourt R, Harrison A-L, Hazen EL, Heupel MR, Hoyt E, Humphries NE, Kot CY, Lea JSE, Marsh H, Maxwell SM, McMahon CR, Notarbartolo di Sciara G, Palacios DM, Phillips RA, Righton D, Schofield G, Seminoff JA, Simpfendorfer CA, Sims DW, Takahashi A, Tetley MJ, Thums M, Trathan PN, Villegas-Amtmann S, Wells RS, Whiting SD, Wildermann NE, Sequeira AMM (2019) "Translating marine animal tracking data into conservation policy and management". Trends in Ecology and Evolution 34, 459-473.
  16. ^ Hays, G.C., Broderick, A.C., Glen, F., Godley, B.J. (2003) "Climate change and sea turtles: a 150-year reconstruction of incubation temperatures at a major marine turtle rookery". Global Change Biology 9, 642-646.
  17. ^ Hays, G.C., Mortimer, J.A., Ierodiaconou, D., Esteban, N. (2014) "Use of Long-Distance Migration Patterns of an Endangered Species to Inform Conservation Planning for the World's Largest Marine Protected Area". Conservation Biology 28, 1636-1644.
  18. ^ "Record-breaking turtle migration exposes limits of marine reserves". Science (28 July 2014). Retrieved 27 June 2021.
  19. ^ Hays, G.C., Proctor, C.A., John, A.W.G., Warner, A.J. (1994) "Interspecific differences in diel vertical migration of marine copepods: The implications of size, colour and morphology". Limnology and Oceanography 39, 1621-1629.
  20. ^ Hinder, S.L., Hays, G.C., Edwards, M., Roberts, E.C., Walne, A.W., Gravenor, M.B. (2012) "Changes in marine dinoflagellate and diatom abundance under climate change". Nature Climate Change 2, 271-275.
  21. ^ Chivers, W.J., Walne, A.W., Hays, G.C. (2017) "Mismatch between marine plankton range movements and the velocity of climate change". Nature Communications 8, 14434.
  22. ^ "As the Seas Warm" by Eli Kintisch, Science (11 Aug 2006), Vol. 313, pp. 776-779.
  23. ^ "Animal magnetism" by Jessa Netting, Nature (07 Nov 2000).
  24. ^ "Fishing kills a third of turtles" by John Whitfield (2003), Nature.
  25. ^ "ABC Breakfast News" Interview (5th May 2014). Retrieved 27 June 2021.