By: Miss Sasheera Mehrani Gounden

Abstract

This paper attempts to analyse the effects of rising sea levels, human interference, microbes found on beach sand, genetic mutations and Hurricane Irma and Harvey on the mortality rate of sea turtles as well as how turtles contribute to the ecosystem and the risks of endangered turtle species. Sea turtles are extremely beneficial to the ecosystem and act as hosts by transferring vital nutrients from sea to land and vice versa. Climate change is one of the main causes of the declining sea turtle population as a result of the melting polar caps that leads to the rise in sea levels, flooding potential nesting areas for sea turtles and affecting the hatching process resulting in the death of many hatchlings. Rising sea levels are a threat to the sea turtle population but human interference remains a major risk factor to the turtle population. As many as 400 sea turtle carcasses were found off the coast of El Salvador in late October 2017. The ‘red tide’ is often blamed but toxicology reports need to be produced and made public by the government to prove what exactly caused the deaths of the sea turtles (Gibbens, 2017). The red tide is often accelerated by high concentration levels of pesticides and other harmful toxins that are deposited in the water.

Introduction

Sea turtles, classified as Archelosauria, spend most of their time underwater. From birth, sea turtles go through a series of challenges and one of these challenges includes surviving through the hatching process. Out of 1000 eggs laid on the beach, only 800 of these survive the hatching process. From 800 sea turtles, a startling number of 400 baby sea turtles dodge every imaginable predator on land to reach underwater. These predators include raccoons, crustaceans and seagulls. Out of 1000 eggs, only 200 sea turtles progress toward adulthood. The turtles who manage to reach the surf face even more danger such as the threat of repelling wave force, certain types of predatory fish, sharks, dolphins and sea birds. An average of 50% of sea turtles that make it to the surf will perish as a result of various predatory species. Larger sea turtles face the threat of larger predators such as bull, tiger and white sharks as well as killer whales. Out of 850-1000 eggs laid, less than 10% remain. When factoring in human interference, the sea turtle population is left dwindling on the brink of extinction. Statistically, 20 sea turtles out of 1000 eggs may survive without human interference. When factoring in humans as a threat to sea turtles considering noxious chemicals such as oil spills, direct fishing and pollution, only 2 out of 1000 eggs may survive to adulthood. Climate change is another major threat to the sea turtle populations due to the rise of sea levels that may destroy potential nesting areas and affect the hatching process.

Causes of Declining Sea Turtle Populations

Human interference is one of the main causes of the declining sea turtle population. A majority of sea turtle species have become endangered as a result of direct sea turtle fishing and poaching. Turtle eggs are considered valuable and edible in Central America and Asia (Sea Turtle Conservancy, 1996). Habitat degradation and climate change are major contributory factors towards sea turtles becoming an endangered species. Global warming is a growing concern for life on Earth. As a result of global warming, sea levels rise from melting polar ice. Global warming leads to frequent storms that result in eroding nesting beaches. An unsteady and frequent increase in temperature as a result of global warming leads to decreasing sea turtle hatching rates. Rising sea levels will affect the survival rate of sea turtle eggs. The rise in sea levels is a result of global warming. The sea turtle nesting areas are in risk of flooding with saltwater, affecting the survival rate of sea turtle eggs. David Pike’s research team from James Cook University found that flooding is not the only factor that contributes to the decline in sea turtle population but the presence of salt may increase the sea turtle mortality rate. The presence of salt in water contributing to the sea turtle mortality rate is simply speculation. The research team concluded that high egg mortality is a natural occurrence as a result of saltwater flooding. When considering egg mortality, it is extremely important to factor in genetics and the mother sea turtle’s health. The researchers came to the conclusion that malignant matter passed from mother to offspring and microbes in the sand passed as a result of irregular sea levels could affect the mortality rate of sea turtle eggs.

Rising Sea Levels: Microbes in the Sand

Beach sand acts as a home to viruses, bacteria and fungi as well as micropsammon, In Monika Buczek’s microbial sciences article: Sandy Beach Microbes: The good, the bad, and the flesh-eating, it is determined that both beneficial and harmful bacteria are deposited on the beach. Buczek reaffirms that David Pike’s research team’s conclusions that the presence of salt affecting the mortality rate of sea turtle eggs is speculation. According to Buczek, freshwater beaches are said to contain positive bacteria per gram of sand. Actinobacteria acts as a cleaning agent and helps keep beaches clean by depositing beneficial organic matter in the sand. Buczek further states that freshwater beaches contain Proteobacteria that uses organic matter to create energy. Numerous studies have concluded that sea turtles and eggs carry mycobacteria as a result of consuming algal blooms that are commonly referred to as [1]‘red tides’ (Fastigi, 2010). Red tides are known to release toxins which cause illness in sea turtles. In the Caribbean, sea turtles and their eggs are considered a delicacy. Sea turtle eggs are believed to be aphrodisiacs and often men from the Caribbean consume turtle eggs to increase their libido. Sea turtle eggs, however, are proven by doctors to inhibit sexual performance as a result of the high pollutant concentration of heavy metals found in the eggs (Fastigi, 2010). A large number of sea turtles are often found contaminated with high concentration levels of pesticides, internal tumors and mercury that may lead to death in humans when consuming contaminated turtle meat (Fastigi, 2010).

Genetic Abnormalities in Sea Turtles

Genetic abnormalities that lead to carapace anomalies in turtles result from deposits of contaminants such as mercury and pesticides in the water that can have a long-term effect on the developing sea turtle. Organochlorine pesticides, mercury and biphenyls were identified as causes of abnormalities in embryos and hatchlings for the snapping turtle (Velo-Anton, Guilherme Becker, Cordero-Rivera, 2011). Many turtles are susceptible to cancerous growths referred to as fibropapillomas. Green sea turtles were the first to acquire fibropapillomas during the 1980s and it has now spread to other turtle species as a result of the deposits of harmful toxins and heavy metals found in the sea (Fastigi, 2010). An article in the September 2006 issue of New Scientist magazine revealed that sea turtles contained extremely high levels of cadmium and mercury that was incredibly high in comparison to tuna. Genetics plays a major part in the hatching and mortality rate of sea turtle eggs. Genetic abnormalities carried by the mother turtle may be passed down to the offspring; previous genetic background determines the ratio of genetic abnormalities present during the first birthing stage. Premature death is common during the hatching process and may be the result of genetics or levels of toxicity found in the mother sea turtle that is often passed down to the eggs.  

Sea Turtles on the Brink of Extinction

Extinction of a species has dire consequences on the ecosystem. A classic example of the consequences of extinction on the ecosystem is the case of the dodo bird that became extinct in 1681 as a result of human and various [2]invasive animal species interference. A scientist had deduced that no new trees of a particular species had germinated in Mauritius since the extinction of the dodo bird. According to Bagheera, an educational website about endangered species, the dodo bird was believed to have eaten the fruit of the rare tree species that was on the brink of extinction and the seeds passed out from the stool assisted the germination process. In Mauritius, the turkey is used to imitate the dodo bird as a result of the striking similarities of the digestive systems and diets of the two birds. [3]The dodo tree is now preserved as a result of successful germination with the assistance of turkeys used in place of the dodo bird. Sea turtles face the possibility of extinction. Finding a replica of the sea turtle to imitate its biological functions will prove challenging and definitely will not result in the case of the dodo bird. A variety of turtle species are classified as being endangered and are on the verge of possible extinction. Green, Hawksbill, Kemp’s, Ridley, Leatherback, Loggerhead and Olive Ridley sea turtles all face the possibility of extinction as they are all classified as endangered species.

Green Sea Turtles

Green sea turtles maintain healthy seagrass beds by constantly grazing on seagrass and as a result increase the growth and nutrient content of the grass. The lack of green sea turtles will cause seagrass beds to overgrow and conceal the bottom of the ocean, decompose and increase the productivity of algae. In Florida Bay, the presence of Green sea turtles has helped destroy greens and algae.

Hawksbill Sea Turtles

Hawksbill sea turtles help maintain coral reef ecosystems. Hawksbill helps remove sponges for coral and other beneficial species to grow. Hawksbill sea turtles have a positive effect on reef communities.

Sea Turtles and Jellyfish

Leatherback turtles are known to consume 199 kg of gelatinous jellyfish a day which is the equivalent of the weight of an adult lion (Wilson, Miller, Allison, Magliocca). Leatherback turtles help control jellyfish populations. Yellowfin tuna is a delicacy for jellyfish and they are known to consume fish eggs (Fastigi, 2010). The extinction of the Leatherback turtle species will lead to the demise of yellowfin tuna and other fish species.

Hurricane Irma

On August 31, 2017, Mother Nature introduced the devastating Hurricane Irma that lasted from 31 August-11 September 2017. It is the strongest hurricane ever recorded outside the Gulf of Mexico. The hurricane caused major flooding and destruction of coastal beaches that ultimately affected the sea turtle population as many nesting areas were destroyed.

Hurricane Harvey

Hurricane Harvey hit Texas on 25 August 2017. The damages were startling and many people were evacuated from the area (Amadeo, 2017). The hurricane caused 800 wastewater treatment facilities to become flooded leading to the spread of sewage and toxic substances to flooded areas (Amadeo, 2017). The spread of toxic substances would be harmful to Texas beaches and therefore have a devastating impact on the sea turtle species as many hatchlings might be infected with harmful toxins that will ultimately lead to their death.

Conclusion

Sea turtles are extremely important and help maintain the health of oceans by regulating the jellyfish population and maintaining seagrass beds to prevent the build-up of algae. Sea turtles help maintain healthy beaches by transferring beneficial nutrients from the sea and help maintain fish species populations. Human interference is one of the main causes of endangered turtle species as a result of direct turtle fishing, poaching and releasing harmful toxins and metals that result in tumours and genetic abnormalities in sea turtles. Climate change is a result of human beings abusing the planet by overpopulation, pollution and greed. The rise of sea levels results from global warming and human beings are responsible for these devastating natural occurrences that seem to be occurring in a short period. Our planet is acting in defence of our actions; Hurricane Irma and Harvey are classic examples of natural defence mechanisms and are signs that earth is dying out. If we do not preserve animal species and limit our carbon footprint, our actions will lead to our demise.

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References

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Bagheera. (2017). The Dodo Bird. Accessed 25 November 2017. http://www.bagheera.com/inthewild/ext_dodobird.htm

Buczek, M. (2017). American Society for Microbiology. Sandy Beach Microbes: The Good, The Bad, and the Flesh-Eating. Accessed 25 November 2017. https://www.asm.org/index.php/general-science-blog/item/6742-sandy-beach-microbes-the-good-the-bad-and-the-flesh-eating

CNN. (2017). Irma: A hurricane for the history books. Accessed 25 November 2017. http://edition.cnn.com/specials/hurricane-irma

Fastigi, M. (2010). Caribbean Compass. Sea Turtles and their Eggs: No Longer Safe Food. Accessed 25 November 2017. http://www.caribbeancompass.com/seaturtles_2010.html

Gibbens, S. (2017). National Geographic. Hundreds of Sea Turtles Found Dead. Accessed 25 November 2017. https://news.nationalgeographic.com/2017/11/sea-turtle-hundreds-die-off-el-salvador-spd/

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Sea Turtle Conservancy. (1996). Information about Sea Turtles: Threats from Harvest for Consumption. Accessed 25 November 2017. https://conserveturtles.org/information-sea-turtles-threats-harvest-consumption/

TED-Ed. (2012). YouTube. The Survival of the Sea Turtle. Accessed 23 November 2017. https://www.youtube.com/watch?v=t-KmQ6pGxg4

Velo-Anton G, Guilherme Becker C, Cordero-Rivera A. (2011). Plus One. Turtle Carapace Anomalies: The Roles of Genetic Diversity and Environment. Accessed 25 November. http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0018714

Whitman R, Harwood VJ, Edge TA, Nevers M, Byappanahalli M, Vijayavel K, Brandão J, Sadowsky MJ, Alm EW, Crowe A, Ferguson D, Ge Z, Halliday E, Kinzelman J, Kleinheinz G, Sands: Integrating Environment, Ecology and Public Health. Accessed 25 November. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4219924/

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[1] Algal blooms are the result of high concentrations of phosphorus and nitrogen in the water that leads to an increase in algae causing a decline in marine life.

[2] The Dutch shipped monkeys and pigs that inhabited the island and destroyed many dodo bird eggs.

[3] The dodo tree is classified as ‘Sideroxylon grandiflorum.’