By Ser, Jooyoung
There are only 7 species of sea turtle on our planet and unfortunately, 6 of them are endangered on the IUCN Red list. Regrettably, the cause of the decrease in sea turtle population size cannot be separated from anthropogenic activity.
About 400 years ago, there were 39 million sea turtles roaming our oceans and maintaining our marine ecosystems; now only 10 million remain – a shocking 74% reduction of population size. Humans are driving and have been driving sea turtles to extinction by both direct and indirect activity. During the colonisation of the Americas by the European country, due to lack of agricultural knowledge and another food source, humans hunted the once abundant sea turtles. Humans relied on these turtles as perfect source of sustenance in the form of flesh and eggs. Turtles were easy food as they were easy to catch, and they could remain ‘fresh’ for months without maintenance. You could argue that without these turtles the Americas would not be the same great continents they are today (SWOT, 2020a).
Due to legislations taking place and hunting rules enforced, hunting is now less of an issue. However, this does not mean that humans are now guilt-free of endangering these species. Sea turtles are now being threatened by things like residential and commercial development; fisheries bycatch; pollution and pathogens as well as climate change. Pollution to our oceans comes in many forms: debris pollution, oil spills, fishing gear and more. It was estimated that over half of the sea turtle population have ingested debris pollution at least once. Ingestion and entanglement in the rubbish that humans deposit in the ocean are extremely harmful to sea turtles. Oil pollution and other chemical pollution can cause turtles to have weakened immune systems and affect their orientation to nesting sites. Climate change not only effects the whole marine ecosystem but also effects sea turtles directly (SWOT, 2020b).
Current conservation action for as listed by the IUCN Red List includes research and monitoring; protection; management and education. However, this is not currently enough, all the sea turtles species require further and more extensive conservation. In order conduct effective conservation research is also needed. The IUCN Red List lists the specific research topics that need to be explored for the sea turtles. Understanding processes underlying their habitat and breeding trends are essential to be able to help these reptiles. The current attempts to conserve the turtles have not been spread evenly among species of sea turtles. For example, the leatherback turtles have had a lot of attention from scientists and have recovered from being critically extinct in 2000 to just vulnerable in 2013 (IUCN, 2021). However, this sort of ‘favouritism’ may not be all too bad. As one species is studied significantly, the knowledge gained from the research and the refined conservation techniques could be extrapolated to help the other species. The sea turtles have overlapping global habitat ranges and are susceptible to similar threats so the scientific research could definitely be shared between them.
In turtles, sex determination is not genetic but rather relies on temperature. Warmer temperatures induce the development of female turtle hatchlings. Therefore, an obvious consequence of climate change is the disturbance of sex ratios in turtles. Despite this, in 2018 promising research about promiscuous loggerhead turtles suggest it may not all be doom and gloom. They found female loggerhead turtles could lay eggs several times during the nesting season and therefore lay up to three batches of eggs each from different fathers (Hickok, 2018). Recent research like this shows that a lot is still unknown about these creatures and more research is required
Seeing as it was us as the human race that caused such a devastating decline in the sea turtle populations, it is our duty to help them recover via methods the of conservation. The ancestors of sea turtles survived the meteor strike that killed off the dinosaurs and an ice age that induced a mass extinction, yet we are driving these magnificent species to extinction.
Hickok, K. (2018) Promiscuous female sea turtles may save their species from climate change. Science (American Association for the Advancement of Science). Available from: doi: 10.1126/science.aat0235.
IUCN. (2021) The IUCN Red List of Threatened Species. Available from: https://www.iucnredlist.org [Accessed Feb 2021].
SWOT. (2020a) FAQs About Sea Turtles.
SWOT. (2020b) Threats to Sea Turtles. Available from: https://www.seaturtlestatus.org/threats-to-turtles [Accessed Feb 2021].