海龟的生命开始于雌性在海滩上筑巢并产卵，通常在她出生的地方附近。每个季节她会筑巢两到八次，每窝产卵约100个。这些蛋很容易受到鸟类，哺乳动物和鱼类等食肉动物的攻击。经过六到八周的时间，幸存的幼龟从卵中脱落（称为“啄”），从沙子中出来，朝向水面。 10,000只幼龟中只有1到1,000比1存活下来才能体验下一阶段的生命：开放的海洋阶段。这段时间持续2到10年，也被称为“失去的岁月”，因为海龟在海上的运动很难监测。虽然海龟可以被科学家标记，但发射器对于年轻的生物来说往往过于笨重。 2014年，来自佛罗里达州和威斯康星州的一组研究人员使用较小的设备来追踪他们养了几个月然后释放的幼龟“失去的岁月”。他们得出的结论是，幼龟会出海捕捉掠食者，并追随温暖的地表水，以支持它们的生长。海龟慢慢长大。它们需要15到50年才能成熟。他们的成年生活在沿海水域觅食，并迁移到海滩交配。只有雌性才能上岸筑巢，这个过程每两到五年发生一次。像鸟类和鱼类一样，海龟依靠地球的磁场返回其出生地。他们的迁移可能很漫长。 2008年，从印度尼西亚到俄勒冈州的12,774英里处追踪棱皮龟。已知雌性在80岁之前筑巢。由于捕食和与人类有关的原因，海龟经常死亡。它们的一些主要捕食者是鲨鱼，虎鲸和石斑鱼等大型鱼类。他们还面临偷猎，渔具纠缠，污染，塑料等海洋垃圾和气候变化等危险。海平面上升和风暴活动增加威胁到筑巢地。在很大程度上由于这些人为威胁，大多数海龟物种都处于濒危状态。
A sea turtle’s life begins when a female nests and lays eggs on a beach, usually near where she was born. She will nest between two and eight times each season, laying about 100 eggs in each nest. The eggs are vulnerable to predators like birds, mammals, and fish. After a period of six to eight weeks, the surviving hatchlings break out of their eggs (called “pipping”), emerge from the sand, and head towards the water. Only an estimated 1 in 1,000 to 1 in 10,000 hatchlings survive to experience the next phase of life: the open ocean phase. This period, which lasts between two and 10 years, is also called “the lost years” because the turtles’ movements at sea are hard to monitor. While turtles can be tagged by scientists, the transmitters are often too bulky for younger creatures. In 2014, a group of researchers from Florida and Wisconsin used smaller equipment to track the “lost years” of hatchlings that they had raised for several months and then released. They concluded that hatchlings head out to sea to avoid predators and follow warm surface waters that support their growth. Sea turtles grow up slowly. It takes them between 15 and 50 years to become reproductively mature. They spend their adult lives foraging in coastal waters and migrate to beaches to mate. Only the females come ashore to nest, a process that takes place every two to five years. Like birds and fish, sea turtles rely on the magnetic field of the planet to return to their place of birth. Their migrations can be lengthy. In 2008, a leatherback was tracked traveling 12,774 miles from Indonesia to Oregon. Females have been known to nest until the age of 80. Sea turtles often die because of predation and human-related causes. Some of their main predators are sharks, killer whales, and large fish like grouper. They also face dangers from poaching, fishing gear entanglement, pollution, marine debris like plastic, and climate change. Rising sea levels and increasing storm activity threaten nesting grounds. Due in large part to these human-made threats, most sea turtle species are endangered.