Turtles are reptiles of the order Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira and Cryptodira, which differ in the way the head retracts.

Seven different species of sea (or marine) turtles grace our ocean waters, from the shallow seagrass beds of the Indian Ocean, to the colorful reefs of the Coral Triangle and the sandy beaches of the Eastern Pacific. While these highly migratory species periodically come ashore to either bask or nest, sea turtles spend the bulk of their lives in the ocean. WWF's work on sea turtles focuses on five of those species: green, hawksbill, loggerhead, leatherback, and olive ridley.

Over the last 200 years, human activities have tipped the scales against the survival of these ancient mariners. Slaughtered for their eggs, meat, skin, and shells, sea turtles suffer from poaching and over-exploitation. They also face habitat destruction and accidental capture—known as bycatch—in fishing gear. Climate change has an impact on turtle nesting sites; it alters sand temperatures, which then affects the gender of hatchlings. Three species of sea turtle are now classified as endangered, with two of those being critically endangered.

Crystal0192 told me to put this -

Tau (τ) is a mathematical constant approximately equal to 6.283. It is defined as the circumference of a circle divided by its radius, and is far more intuitive than π. Tau naturally appears from the angle measure system called radians, in which the angle theta (Θ) is defined as the length of the arc (a) divided by radius (r). When you take the angle measure of a full circle, you divide circumference by radius, yielding tau. This means that the "Special Angles" like π/2 (a quarter of a circle) or 3π/2 (three quarters of a circle) no longer require memorization, because all you have to do to get the radian measure of the arc of a circle is take the fraction of the circle that the arc traces out, and multiply it by τ (e.g. 1/4 circle is τ/4, two thirds circle is 2τ/3), and this makes radians much much simpler. Tau is a better number because it relates a circle's circumference directly to its radius, and since a circle is defined by its radius, tau is the more natural constant. This makes τ far better for teaching students than π. Not only that, but 2π (Which equals τ) occurs far more often than π alone. Even when π occurs by itself in a formula or equation, it is the result of the simplification of τ/2 to π. A prime example of this is in the formula for the area of a circle. To derive the formula, you have to integrate circumference with respect to radius, which yields τr^2/2, only then can you simplify this formula into its more common form: πr^2. 2π occurs all over physics and mathematics; it is the period of a sine wave, the upper limit of theta integration over all space in polar coordinates, and it is the denominator of a fraction commonly denoted as h-bar, which is Plank's constant divided by... 2π! Using tau instead of pi would simplify many mathematical formulas. I cannot summarize all of the wonderful features of tau in this short paragraph, and my humble words fail to express the amazing superiority of τ when compared to π.

HannahDaMagicBanana