Sea Turtle Diet – What Each Turtle Species Eat

Green sea turtles eat sea grass as adults. image.
Adult green sea turtle eating sea grass. ©Stephanie Köhnk

Sea turtles inhabit all the oceans of the world except the Arctic, and they therefore have a broad range of habitats and diets. Each species has uniquely evolved to different environments and available food [1]. Some are nomadic marathon swimmers and others call coral reefs their home. There are seven species of sea turtles found globally.  So, who eats what and what does a sea turtle diet consist of?

An Eggcellent Start

All sea turtles start out life as eggs. Female turtles dig nests deep in the ground and lay clutches containing many eggs. Energy from the female turtle is stored as the egg yolk. This allows a sea turtle to fully develop from just a few cells to a fully formed independent hatchling [2].

Aside from the vital energy provided by the yolk, eggs also exchange heat, water, oxygen and carbon dioxide with other eggs and the surrounding sand [2][3].

A green turtle laying eggs. Still from video by ©Beth Faulkner, Manta Trust.

The composition of the egg yolk is directly affected by the diet of the mother turtle [4]. Not only does the mother influence the nutritional content of her eggs, but she can also pass on unnatural chemicals and pollutants. 

Human activity has led to harmful pollutants, like pesticides, being taken up by foraging turtles and passed on to their eggs [5].

Green turtle hatchling emerging from the egg. Image.
A green turtle hatchling emerging from the egg. ©Joana Hancock.

Sea Turtle Diet By Species

Green Turtle Diet: From Carnivore to Herbivour

Green turtles begin their life living in open ocean near the surface. They start out with a generally carnivorous diet for the first 3-5 years, which can include zooplankton, mollusks, and crustaceans. [7]

As they grow, juvenile green turtles move to coastal waters and reefs and shift to a more herbivorous diet. Juvenile greens eat mainly seagrasses and algae [8], however, their diet can also include a number of invertebrate species such as jellyfish and sponges. [6][9].

As adults, green turtles have a unique “vegetarian” diet.  Adult green turtles live in shallower waters with a primarily herbivorous diet, thriving on sea grass. [6] Just like cows grazing on terrestrial pastures, adult greens are going to ingest the occasional invertebrate together with the seagrass by accident.

Green turtle eating seagrass, Maldives. Image.
Green turtle eating seagrass, Maldives. ©Kristina Loosen

Hawksbill Turtle Diet: Mostly Spongy

Hawksbill turtles start their life in the open ocean with a similar diet to green turtle hatchlings, [10] including macroplankton, barnacles, fish eggs, crabs, and algae [11][12].

Juvenile and adult hawksbill turtles live and thrive on coral reefs, primarily eating sponges [13][14]. While hawksbill turtles in the Caribbean live nearly exclusively of sponges, their Indian Ocean cousins feast on a wider range of organisms also including corals, sea urchins and jellyfish in their diet [11][13][15].

Sponges are are a major part of hawksbill turtles' diet. Image.
Sponges are are a major part of hawksbill turtles’ diet. ©Joana Hancock

Leatherback Diet: All About Jellyfish

Leatherback turtles swim great distances, live in open ocean and primarily feed on jellyfish. In addition to true jellyfish, leatherback turtles have been reported to feed on other soft bodied organisms (pyrosomes and siphonophores) as well as squid and octopus. [11][15]

Jellyfish swimming in the blue sea, Kenya. Image
Jellyfish swimming in Kenya. ©Joana Hancock

Olive Ridley Diet: All Eating

Adult olive ridleys tend to live in the open ocean with a broad omnivourous diet. Their diet includes crabs, mollusks, algae, jellyfish and shrimp [16]. They are also known to eat fish, showing opportunistic feeding behaviour [17][18]. Apart from the open ocean, olive ridley are also known to feed in shallower areas as “bottom feeders”, diving to feed on organisms living on the ocean floor [18][19].

Turtle patient Azura eating lobster. Image.
Turtle patient Azura, an olive ridley, eating lobster ©ORP

Loggerhead Diet: True Carnivores

Loggerhead turtles are carnivores, feeding on a variety of prey depending on their life stage. [15]

Juvenile and adult loggerheads feed on a variety of crustaceans found on the ocean floor, including crabs, lobster and shrimp.  They eat snails, mussels and even small amounts of sea grasses and algae [22][23][24]. There has also been reports of opportunistic feeding on fish caught or discarded by fishermen [25].

Emme baby loggerhead sea turtle recoving in ORP rescue centre pool
Emme, a young loggerhead sea turtle, diving for tuna. ©ORP

Kemps Ridley Diet: Mostly Crustaceans

Kemps ridley turtles are only found in the Northwest Atlantic Ocean. Juvenile and adults primarily feed on crabs. They also eat other crustaceans and mollusks and occasionally fish – showing the ability to be opportunistic feeders. [20][21]

Trapezia lutea orange coral crab. Image
Coral crabs (Trapezia lutea pictured) are part of a sea turtle’s diet. ©Stephanie Köhnk

Flatback Diet: Soft Bodied Invertebrates

The Flatback sea turtle lives exclusively in Australia and little is known about the species and their diet throughout their lifetime. Juvenile and adult flatbacks are known to eat snails, jellyfish, corals and other soft bodied invertebrates.[26][27][28]

Goniobranchus gleniei nudibranch, Maldives. Image.
Nudibranches, or sea slugs, are a favourite of flatbacks.
This is a Goniobranchus gleniei. ©Stephanie Köhnk

How Does Sea Turtles’ Diets Affect The Ocean Ecosystems?

Sea turtles play a vital role in ocean ecosystems, affecting the diversity and function of ocean habitats [29].  Here are just a few examples.

Green Sea Turtles Maintain Healthy Seagrass Beds

Female green turtle on sea grass, Lhaviyani Atoll, Maldives
Mareena, a female green turtle, on a seagrass meadow in the Maldives. ©ORP

Green sea turtles are vital in maintaining healthy beds of seagrass.  They prevent seagrass becoming overgrown and by grazing they even improve the quality and growth of the grass [30].  Overgrown sea grass can decompose and develop a build up of algae, bacteria and fungus.  The die-off of seagrass in Florida during the 1980s has been directly linked with the dramatic decline in green turtle populations [31].

Hawksbills Manage Sponges On Coral Reefs

Hawksbill turtle eating sponge, Maldives. Image.
A hawksbill turtle eating sponge in Maldives. ©ORP

Hawksbill turtles manage sponges on coral reefs.  Sponges compete with corals for space on reefs and without predators they would quickly take over. Hawksbills are one of the few marine animals that can eat these toxic sponges, allowing corals to grow and thrive.[32][33]

Sea Turtles Keep Jellyfish Populations Under Control

Hawksbill turtle eating jellyfish. Image.
A hakwsbill turtle eating a jellyfish in Maldives. ©ORP

Several species of sea turtles, but particularly the leatherback, play a key role in managing jellyfish populations.  A top jellyfish predator, the huge size of leatherbacks means they can consume up to 200kg of jellyfish a day![34] Jellyfish eat fish eggs and larvae and compete for fish food. [35] So a decline in leatherbacks could mean more jellyfish and fewer fish in our oceans. [36]

Bottom Feeders Improve Aeration On the Sea Bed

Loggerheads and other species that feed on crustaceans on the ocean floor increase rates of nutrient recycling by crushing shells during feeding [29][37]. During their hunt for prey, loggerheads create trenches in the sea floor. By clearing sand they improve aeration and nutrient distribution on the sea bed, benefitting the ecosystem. [29][38]

What Sea Turtles Shouldn’t Eat

Sea turtles have survived for millions of years and each species has adapted to different diets. Through the natural abundance of the ocean, they have flourished in various habitats and available food sources. As we have just learnt, they also play key roles in a healthy marine ecosystem. 

Plastic pieces collected from hawksbill turtle pateint Ash's feces. Image.
Some of the plastic pieces found in the feces of Ash, a juvenile hawksbill turtle patient, at the ORP Marine Turtle Rescue Centre. ©ORP

However, a new threat has emerged in the last few decades. A previously unknown material to marine life, plastic now pollutes our oceans [39]. Sea turtles around the world are ingesting plastic with devastating consequences. Plastic can cause blockages in the gut, malnutrition and death [40]. Globally, estimates of around 52% of all sea turtles have ingested plastic [41][42]. In some areas this estimate is even higher! For example, in a study off the coast of Brazil, turtles accidentally caught in fishing nets were examined and an astonishing 90% of juvenile green turtles were found to have ingested plastic [43].

Sea turtles ingest plastic most likely because they confuse the artificial material with actual food items. A plastic bag floating in the ocean can easily be mistaken for a jellyfish.If we want to protect sea turtles, and through them our oceans at large, we again have to rethink our plastic consumption and waste production.

Learn More About Sea Turtles

Enroll in our online courses to learn more about sea turtles. Both courses are free and designed for self-paced learning.

Free

Sea Turtle Science & Conservation

Deep dive into sea turtle science and conservation. Suitable for budding conservationists and those with an interest in the science surrounding turtles, their biology and conservation.

Learn More

Free

e-Turtle School – All About Sea Turtles

Everything you have ever wanted to know about sea turtles, from evolution to conservation. Suitable for all sea turtles lovers and those who want to learn more about these fascinating creatures.

Learn More


Got More Sea Turtle Questions?

c Expand All C Collapse All

Sea Turtles FAQ – The Answers to All Your Sea Turtle Questions

Male hawksbill popping head above surface for air, Maldives. Image.
Marvin, male hawksbill, coming up for a breathe, Maldives.

Sea turtles can hold their breath for several hours, depending on their level of activity.

If they are sleeping, they can remain underwater for several hours. In cold water during winter, when they are effectively hibernating, they can hold their breath for up to 7 hours. This involves very little movement.

Although turtles can hold their breath for 45 minutes to one hour during routine activity, they normally dive for 4-5 minutes and surfaces to breathe for a few seconds in between dives.

However, a stressed turtle, entangled in a ghost net for instance, quickly uses up oxygen stored within its body and may drown within minutes if it cannot reach the surface.

Learn More About Sea Turtles – Free Online Courses

Free

e-Turtle School – All About Sea Turtles

Everything you have ever wanted to know about sea turtles, from evolution to conservation. Suitable for all sea turtles lovers and those who want to learn more about these fascinating creatures.

Learn More

Free

Sea Turtle Science & Conservation

Deep dive into sea turtle science and conservation. Suitable for budding conservationists and those with an interest in the science surrounding turtles, their biology and conservation.

Learn More



References:

  • Hays GC, Akesson S, Broderick AC, Glen F, Godley BJ, Luschi P, Martin C, Metcalfe JD & Papi F 2001. The diving behaviour of green turtles undertaking oceanic migration to and from Ascension Island: dive durations, dive profiles and depth distribution. Journal of Experimental Biology 204: 4093-4098.
  • Hays GC, Hochscheid S, Broderick AC, Godley BJ & Metcalfe JD 2000. Diving behaviour of green turtles: dive depth, dive duration and activity levels. Marine Ecology Progress Series 208: 297-298.
  • Hochscheid S, Bentivegna F & Hays GC 2005. First records of dive durations for a hibernating sea turtle. Biology Letters 1: 82-86.
  • Lutz PL and Musik JA (eds.) 1996. The Biology of Sea Turtles Volume I. CRC Press.

The actual documentation of a sea turtle’s age in the wild is difficult or nearly impossible. Individual turtles can be tracked for a shorter time of six month to three years with the help of satellite transmitters. Longterm studies rely on capture-recapture principle, just like our turtle photo id project. Each photo of a turtle represents a recapture event documenting that the individual is still alive.

A study of nesting green turtles in Hawaii observed female turtles returning to nest for up to 38 years after they were first identified. Assuming the average age at first nesting activity of 24 years, this would show that green turtles can live to up to at least 62 years.

Similar estimates have been made for loggerhead turtles.

An adult green turtle resting on a reef in Maldives, image
An adult green turtle
Hawksbill turtle resting on the reef, Maldives
An adult hawksbill turtle

References:

  • Dodd C 1988. Synopsis of the biological data on the loggerhead sea turtle. Ecology 88.
  • Humburg IH and Balazs GH 2014. Forty Years of Research: Recovery Records of Green Turtles Observed or Originally Tagged at French Frigate Shoals in Northwestern Hawaiian Islands, 1973-2013. NOAA Technical Memorandum NMFS-PIFSC-40.

When sea turtles are juveniles, it is very difficult to tell their sex by eye as they do not differ externally. However, after reaching sexual maturity male sea turtles develop a long tail, which houses the reproductive organ. The tail may extend past the hind flippers.

Female turtles have a short tail, which generally doesn’t extend more than 10 cm (4 inches) past the edge of the carapace. Male sea turtles (except leatherbacks) have elongated, curved claws on their front flippers to help them grasp the female when mating.

The sex of a sea turtle embryo is determined by the temperature of the sand: warm temperatures result in more females while cooler temperatures result in more males.

Male green turtle tail
Male green turtle tail
Female green turtle tail
Female green turtle tail

The olive and kemp’s ridley sea turtles are the smallest species, growing only to about 70 cm (just over 2 feet) in shell length and weighing up to 45 kg (100 lbs). Leatherbacks are the largest sea turtles. On average leatherbacks measure 1.5 – 2m (4-6 ft) long and weigh 300 – 500 kg (660 to 1,100 lbs). The largest leatherback ever recorded was 2,56 m (8.4 ft) long and weighed 916 kg (2,019 lbs) !

Kemp’s Ridley

Nesting female kemp's ridley turtle, nicknamed
Nesting female kemp’s ridley turtle, nicknamed “Mij”, laying 116 eggs on Galveston’s East Beach. ©Ron Wooten, Wildscreen Exchange.

55.6-66.0 cm carapace length, weight range of 25-54 kg for nesting females.

References:

  • Marquez-M R 1994. Synopsis of Biological Data on the Kemp’s Ridley Turtle, Lepidochelys kempi (Garman, 1880). NOAA Technical Memorandum NMFS-SEFSC-343.

Olive Ridley

Female Oliver ridley turtle nesting on the beach during arribada
Nesting female olive ridley turtle ©Susie Gibson.

Curved carapace length 52.5-80.0 cm, weight less than 50 kg (average 35.7 kg) for nesting females.

References:

  • Qureshi M 2006. Sea turtles in Pakistan. In: Shanker K and Choudhury BC (Eds.). Marine Turtles of the Indian Sub- continent. Heydarabad: India Universities Press, pp. 217–224.Reichart HA 1993.
  • Reichart HA 1993. Synopsis of biological data on the olive ridley sea turtle Lepidochelys olivacea (Eschscholtz 1829) in the western Atlantic. NOAA Technical Memorandum NMFS-SEFSC-336.

Hawksbills

Adult male hawksbill turtle swimming in the blue, Maldives. Image
Adult male hawksbill, Maldives.

Nesting females reported between 53.3 and 95.5 cm carapace length, with weight between 27.2 and 86.2 kg.

References:

  • Witzell WN 1983. Synopsis of biological data on the hawksbill turtle, Eretmochelys imbricata (Linnaeus, 1766). No. 137. Food & Agriculture Org.

Green turtles

Adult green turtles mating, Malsdives. Image.
Adult green turtles mating, Maldives.

Nesting green females reported curved carapace length 75-134 cm, weight (after egg deposition) 45-250 kg (!).

References:

  • Hirth HF 1997. Synopsis of the Biological Data on the Green Turtle Chelonia mydas (Linnaeus, 1758). Vol. 2. Fish and Wildlife Service, US Department of the Interior.

Flatbacks

Nesting flatback sea turtle ©Lyndie Malan / CC BY-SA.

Ones study (Ref. 1) found nesting females have a mean curved carapace length 86.3 cm, and mean weight of 67.4 kg. Another study (Ref. 2) found flatbacks to be between 87.5-96.5 cm.

References:

  • Schäuble C, Kennett R and Winderlich S 2006. Flatback Turtle (Natator depressus) nesting at Field Island, Kakadu National Park, Northern Territory, Australia, 1990-2001. Chelonian Conservation and Biology 5: 188-194.
  • Limpus CJ 1971. The Flatback Turtle, Chelonia depressa Garman in Southeast Queensland, Australia. Herpetologica 27: 431-446.

Loggerheads

Adult female loggerhead, Oman.

The largest loggerhead was reported stranded in 1938 on the welsh coast (Tenby, Pembrokshire) with a carapace length of 146.7 cm. The turtle was highly emaciated and missing a front flipper. It was reported to weigh only 27.8 kg, which is severely underweight for a turtle of that size. On average nesting and therefore adult female loggerheads have a curved carapace length of 65.1-114.9 cm and weigh between 40.0 and 180.7 kg. Males fall into the same size range (79.0-104.0 cm curved carapace length).

References:

  • Brongersma LD 1972. European Atlantic turtles. Zoologische Verhandlingen 121, Leiden.
  • Dodd C 1988. Synopsis of the biological data on the loggerhead sea turtle. Ecology 88: 1-119.

Leatherbacks

Leatherback Turtle, Claudia Lombard, USFWS
Adult leatherback turtle ©Claudia Lombard, USFWS.

143.8-169.5 cm curved carapace length, weight 259-506 kg recorded for nesting females all around the world. Largest ever recorded specimen was found dead on a beach on the coast of Wales. The adult male turtle weighed 916 kg and its shell was 256.5 cm long. An autopsy revealed that it had drowned.

References:

  • Eckert KL and Luginbuhl C 1988. Death of a Giant. Marine Turtle Newsletter 43: 2-3.
  • Eckert KL, Wallace BP, Frazier JG, Eckert SA and Pritchard PCH 2012. Synopsis of the Biological Data on the Leatherback Sea Turtle (Dermochelys coriacea). Biological Technical Publication BTP-R4015-2012, US Fish & Wildlife Service.
Hawksbill turtle eating jelly fish
A hawksbill turtle eating a jellyfish. ©Lauren Arthur.
A green turtle eating sea grass.

Each sea turtle species feeds on a specific diet and all lack teeth:

  • Loggerheads feed mainly on hard-shelled organisms such as lobsters, crustaceans, and fish.
  • Green turtles are vegetarian and prefer sea grasses, sea weeds and algae as adults, however, green turtle hatchlings are omnivorous, eating jellyfish, snails, crabs, and shrimp.
  • Leatherbacks feed mostly on jellyfish.
  • Hawksbills have a bird-like beak that is used to cut through soft coral, anemones and sea sponges.
  • Olive ridleys are omnivorous, mostly eating jellyfish, snails, crabs, and shrimp but they will occasionally eat algae and seaweed as well.

Hungry Hungry Hawksbill

https://www.facebook.com/OliveRidleyProject/videos/822663814590269/
Watch the video of a very hungry hawksbill turtle in the Maldives.

Learn More About Sea Turtles – Free Online Courses

Free

e-Turtle School – All About Sea Turtles

Everything you have ever wanted to know about sea turtles, from evolution to conservation. Suitable for all sea turtles lovers and those who want to learn more about these fascinating creatures.

Learn More

Free

Sea Turtle Science & Conservation

Deep dive into sea turtle science and conservation. Suitable for budding conservationists and those with an interest in the science surrounding turtles, their biology and conservation.

Learn More


References:

[1] HENDRICKSON, J.R. 2015. The Ecological Strategies of Sea Turtles. American Zoologist, Volume 20, Issue 3, August 1980, Pages 597–608

[2] Ackerman R.A. 1997.  The Nest Environment and the Embryonic Development of Sea Turtles, in The Biology of Sea Turtles. Lutz P.L, Musick J.A. CRC Press, Boca Raton, FL.

[3] Ackerman, R. (1981). Growth and Gas Exchange of Embryonic Sea Turtles (Chelonia, Caretta). Copeia, 1981(4), 757-765.

[4] Craven, K.S., Parsons, J., Taylor, S.A. et al. 2008. The influence of diet on fatty acids in the egg yolk of green sea turtles, Chelonia mydas . J Comp Physiol B 178, 495–500.

[5] Van de Merwe JP, Hodge M, Whittier JM, Ibrahim K, Lee SY (2010) Persistent organic pollutants in the green sea turtle Chelonia mydas: nesting population variation, maternal transfer, and effects on development. Mar Ecol Prog Ser 403:269-278

[6] Arthur, K.E., M.C. Boyle, and C.J. Limpus. 2008a. Ontogenetic changes in diet and habitat use in green sea turtle (Chelonia mydas) life history, Mar. Ecol. Prog. Ser. 362: 303–31

[7] Reich, K.J., K.A. Bjorndal, and A.B. Bolten. 2007. The ‘lost years’ of green turtles: Using stable isotopes to study cryptic life stages, Biol. Lett. 3: 712–714.

[8] McDermid, Karla J.; Stuercke, Brooke; Balazs, George H. Nutritional composition of marine plants in the diet of the green sea turtle (Chelonia mydas) in the Hawaiian Islands. Bulletin of Marine Science, Volume 81, Number 1, July 2007, pp. 55-71(17)

[9] Boyle, M.C., and C.J. Limpus. 2008. The stomach contents of post-hatchling green and loggerhead sea turtles in the southwest Pacific: an insight into habitat association, Mar. Biol. 155: 233–

[10] Bolten, A.B. 2003. Variation in sea turtle life history patterns: Neritic vs. oceanic developmental stages, in The Biology of Sea Turtles, Vol. II, Lutz, P., J. Musick, and J. Wyneken, Eds., CRC Press, Boca Raton, pp. 243–258.

[11] Bjorndal, K.A. 1997. Foraging ecology and nutrition of sea turtles, in The Biology of Sea Turtles, Vol. I, Lutz, P.L., and J.A. Musick, Eds., CRC Press, Washington DC, pp. 199–231.

[12] Limpus, C.J. 2009. A Biological Review of Australian Marine Turtle Species. 3. Hawksbill Turtle, Eretmochelys imbricata Linnaeus. Queensland Environmental Protection Agency, Brisbane, Queensland, Australia, 53pp

[13] León, Y.M., and K.A. Bjorndal. 2002. Selective feeding in the hawksbill turtle, and important predator in coral reef ecosystems, Mar. Ecol. Prog. Ser. 245: 249–258.

[14] Meylan, A. 1988. Spongivory in hawksbill turtles: A diet of glass, Science 239: 393–395.

[15] Jones, T.T., and J.A. Seminoff. 2013. Feeding biology: Advances from field-based observations, physiological studies, and molecular techniques, in The Biology ofSea Turtles, Vol. III, Wyneken J., J. Musick, and K. Lohmann, Eds., CRC Press, Boca Raton, pp. 211–248.

[16] Behera, S., Tripathy, B., Sivakumar, K. et al. Stomach Contents of Olive Ridley Turtles (Lepidochelys Olivacea) Occurring in Gahirmatha, Odisha Coast of India. Proc Zool Soc 68, 91–95 (2015).

[17] Liliana Poggio Colman, Cláudio Luis S. Sampaio, Marilda Inês Weber, Jaqueline Comin de Castilhos; Diet of Olive Ridley Sea Turtles, Lepidochelys olivacea, in the Waters of Sergipe, Brazil. Chelonian Conservation and Biology 1 December 2014; 13 (2): 266–271

[18] Reichart, H.A. 1993. Synopsis of biological data on the olive ridley sea turtle Lepidochelys olivacea (Eschscholtz 1829) in the western Atlantic. NOAA Tech. Memo. NMFS-SEFSC-336, 78 pp.

[19] Morreale, S.J., P.T. Plotkin, D.J. Shaver, and H.J. Kalb. 2007. Adult migration and habitat utilization: ridley turtles in their element, in Biology and Conservation of Ridley Sea Turtles, Plotkin, P.T., Ed., Johns Hopkins University Press, Baltimore, pp. 213–230.

[20] Jennifer A. Servis; Gretchen Lovewell; Anton D. Tucker. Diet Analysis of Subadult Kemp’s Ridley (Lepidochelys kempii) Turtles from West-Central Florida. Chelonian Conservation and Biology (2015) 14 (2): 173–181.

[21] EE Seney, JA Musick. Diet analysis of Kemp’s ridley sea turtles (Lepidochelys kempii) in Virginia. Chelonian Conservation and Biology, 2005. 864-871

[22] Plotkin, P.T., M.K. Wicksten, and A.F. Amos. 1993. Feeding ecology of the loggerhead sea turtle Caretta caretta in the northwestern Gulf of Mexico, Mar. Biol. 115: 1–

[23] Tomas, J., F.J. Aznar, and J.A. Raga. 2001. Feeding ecology of the loggerhead turtle Caretta caretta in the western Mediterranean, J. Zool. 255: 525–5

[24] Lazar, B., R. Gracan, D. Zavodnik, and N. Tvrtkovic. 2005. Feeding ecology of “pelagic” loggerhead turtles, Caretta caretta, in the northern Adriatic Sea: Proof of an early ontogenetic habitat shift, in Twenty Fifth Annual Symposium on Sea Turtle Biology and Conservation, Savannah, Georgia, 18–22 January, pp. 93

[25] Seney, E.E., and J.A. Musick. 2007. Historical diet analysis of loggerhead sea turtles (Caretta caretta) in Virginia, Copeia 2007: 478–489.

[26] Walker, T.A. 1991. Juvenile flatback turtles in proximity to coastal nesting islands in the Great Barrier Reef Province, J. Herpetol. 25: 246–248.

[27] Walker, T.A., and C.J. Parmenter. 1990. Absence of a pelagic phase in the life cycle of a flatback turtle, Natator depressa (Garman), J. Biogeog. 17: 275–2

[28] Limpus, C.J. 2007. A Biological Review of Australian Marine Turtle Species. 5. Flatback Turtle, Natator depressus Garman. Queensland Environmental Protection Agency, Brisbane, Queensland, Australia, 53 p

[29] Wilson, E.G., Miller, K.L., Allison, D. and Magliocca, M. 2010. Why Healthy Oceans Need Sea Turtles: The importance of sea turtles to marine ecosystems. Oceana. Available at: https://oceana.org/sites/default/files/reports/Why_Healthy_Oceans_Need_Sea_Turtles.pdf. Accessed: 12.11.20

[30] Thayer, G., Bjorndal, K., Ogden, J., Williams, S., & Zieman, J. 1984. Role of Larger Herbivores in Seagrass Communities. Estuaries, 7(4), 351-376.

[31] Jackson, J.B.C., Kirby, M.X., Berger, W.H., Bjorndal, K.A., Botsford, L.W., Bourque, B.J., Bradbury, R.H., Cooke, R, Erlandson, J., Estes, J.A., et al. 2001. Historical overfishing and the recent collapse of coastal ecosystems. Science 293(5530): 29–637.

[32] Leon, Y.M. and Bjorndal, K.A. 2002. Selective feeding in the hawksbill turtle, an important predator in coral reef ecosystems. Marine Ecology Progress. Series 245: 249-258

[33] Meylan, A. 1988. Spongivory in hawksbill turtles: A diet of glass. Science 239(4838): 393-395

[34] Houghton, J.D.R., Doyle, T.K., Wilson, M.W., Davenport, J., and Hays, G.C. 2006. Jellyfish aggregations and leatherback turtle foraging patterns in a temperate coastal environment. Ecology 87(8): 1967-1972

[35]Purcell, J.E. and Arai, M.N. 2001. Interactions of pelagic cnidarians and ctenophores with fish: A review. Hydrobiologia 451: 27-44

[36] Lynam, C.P., Gibbons, M.J., Axelsen, B.E., Sparks, C.A.J., Coetzee, J., Heywood, B.G., Brierley, A.S. 2006. Jellyfish overtake fish in a heavily fished ecosystem. Current Biology 16(13): R492-R493

[37] R Bjorndal, K. A. and Jackson, J.B.C. 2003. Roles of sea turtles in marine ecosystems: Reconstructing the past. In Lutz, P.L., Musick, J.A. and Wyneken, J. (Eds.) The Biology of Sea Turtles Volume II. CRC Press, Boca Raton, Florida (USA). Pp. 259-273.

[38] Preen, A. R. 1996. Infaunal mining: A novel foraging method of loggerhead turtles. Journal of Herpetology 30(1): 94-96

[39] Haward, M. 2018. Plastic pollution of the world’s seas and oceans as a contemporary challenge in ocean governance. Nat Commun 9, 667.

[40] Nelms, S. E. et al. 2016. Plastic and marine turtles: a review and call for research. ICES J. Mar. Sci. 73(2), 165–181.

[41] Wilcox, C., Puckridge, M., Schuyler, Q.A. et al. 2018. A quantitative analysis linking sea turtle mortality and plastic debris ingestion. Sci Rep 8, 12536

[42] Schuyler, Q. A. et al. 2015. Risk analysis reveals global hotspots for marine debris ingestion by sea turtles. Global Change Biol. 22(2), 567–576.

[43] Gonzalez Carman, V. et al. 2014. Young green turtles, Chelonia mydas, exposed to plastic in a frontal area of the SW Atlantic. Mar. Pollut. Bull. 78, 56–62.