When we look back in history, the modern day sea turtle has existed for around 80 million years, and they can be found in all ocean waters except the polar regions. Of the 7 living species, 2 species are critically endangered, 1 species is endangered, 3 species are vulnerable and 1 species is data deficient.
Threats to these incredible creatures fall more recently at our own feet. In the past they have been overfished through bycatch, but in recent years climate change, coastal development, and more importantly marine debris are the biggest causes of sea turtle decline worldwide
Plastics are a major concern as in some cases turtles are unable to tell the difference between plastics and food. Species that feed on jellyfish can easily become confused by a plastic bag and will often ingest them. Juveniles that spent their formative years floating on the surface in pelagic seas often consume anything that floats into the microhabitat in which they live. This can include microbeads, cigarette butts, plastics and more. Another concern for these juveniles is that they are also likely to ingest trash that has become covered in pollutants, chemicals, and toxins which can be deadly.
However it is not just plastics, there has in recent years been a significant increase in the number of toxins that are making their way into marine food webs, both in the plastics themselves and in liquid form. The pollutants that contaminate the food that these turtles consume can be in the form of toxins, fertilisers, petroleum, oil, and other novel chemicals which usually find their way into coastal waters by urban runoff. These pollutants have recently been linked with a disease that greatly affects sea turtles known as fibropapillomatosis. The disease believed to be a strain of the herpes virus often kills turtles if not treated as if forms tumours on the face and flippers preventing the turtle from eating, diving and avoiding predators.
Discarded ropes and nets create a further problem for these air breathers. If turtles become tangled in nets or caught on lines then they will be unable to take a breathe at the surface and will sadly perish. These discarded items also create a further problem as turtles are often caught entangled in them. This entrapment can cause loss of circulation and ultimately the limb, or can prevent the turtle from being able to dive or swim.