This good and important question! First, let me give you some background on sea turtles, and then talk about why they are so endangered. Sea turtles are found in all of the worlds oceans except the cold polar areas. There are eight species of sea turtles: green, black, loggerhead, Kemps ridley, olive ridley, hawksbill, flatback and leatherback. Sea turtles are reptiles. They are very important in maintaining healthy marine ecosystems and as they disappear from oceans, the marine ecosystems they live in suffer. Although they spend most of their time in the ocean, like all reptiles (and us), they need to breathe air. A lot about sea turtles biology is still being learned. We know that they live long lives, with life spans estimated to be around 80 years, and they are believed to be able to reproduce for about 30 years. Different species migrate to breed up to several thousand miles through the ocean. Female sea turtles come up from the ocean to lay their eggs on sandy shores, laying 50 to 200 eggs into holes they dig as nests. Females may nest several times during a season. Most of the hatchlings from these nests do not make it to adulthood, for those who do, there are a number of threats they face.

All eight species of sea turtles are endangered or threatened. People around the world have recognized that sea turtles are threatened and are working to keep these incredible animals from going extinct.

There are both natural and man-made threats to sea turtle survival. Nests can be disturbed by animals, like dogs, raccoons and large birds, which will eat the sea turtle eggs. Peoples activities, like bringing motorized vehicles on beaches, can also hurt nests. Hatchlings face the challenges of being eaten by animals, and also finding the ocean their navigation to the sea is often disturbed by artificial lighting. Because hatchlings find the shore by walking towards the moonlight, bright streetlights can cause them to become disoriented. Some people also harvest the eggs and hatchlings for food or cultural things, like jewelry. Because of these factors, conservation efforts have tried to protect nests against harm from both animals and people by monitoring nesting sites, and decreased artificial lights in areas where turtles nest. In the US, it is against the law to disturb a sea turtle or their nests.Once sea turtles have made it to the sea, they face a whole new set of challenges. The biggest threats to sea turtles populations come when they are adults, because so few hatchlings ever reach maturity. Although fully grown sea turtles have few natural enemies (just some sharks and killer whales), juvenile turtles may be eaten by predators like larger fish. The main threat to sea turtles is people. Through commercial fishing, many turtles get caught in nets and drown. Nets now are required to have Turtle Excluder Devices (TEDs) which allow them to go through nets they are tangled in. TEDs have saved thousands of sea turtles from drowning as by-catch. Some sea turtles die from eating trash things like plastic like bags can be mistaken for jellyfish by sea turtles and eaten. Stopping trash from going into our oceans is a good way to fight this. Sea turtles are also often injured or killed by collisions with boat propellers putting cages on boat propellers is a way to lessen this risk to them.

Sea turtles have been hunted for centuries for their meat and their eggs. This probably is the most important contributor to their low numbers. Turtles are also hunted for their shells to make jewelry, combs, and brushes, particularly in Asian countries. Although hunting turtles is illegal now, turtles can be caught accidentally in nets that are laid for fish and there is also a lot of illegal poaching that still occurs.

Turtle habitat is also being threatened. Turtles return to the same beach that they were hatched to lay their own eggs. Often when they return they find that their beach has been developed, meaning that people have built things like houses on the beach. This makes it difficult and dangerous for turtles to lay their eggs and for the baby turtles to return to sea if they are able to hatch. Turtles might be discouraged to lay eggs because of the presence of people or people might accidentally (or purposefully) destroy a nest. In these cases, conservationists now have to dig up nests and relocate them to a safer area. Development of the coastline also tends to bring more lights (for example, street lights or car headlights). When turtles hatch at night, they can be confused by these lights and head towards the land instead of towards the ocean.

Sea turtles can also be afflicted by a disease called fibropapillomatosis, which causes tumors to develop on the turtle. This had definitely reduced turtle populations in Florida and in Hawai'i.