Reproduction
In the northernmost areas of the Great Barrier Reef neighboring northeastern Australia, roughly 99% of juvenile green turtles are female. Likewise, in the cooler and the southernmost parts of the barrier reef, about 69% of these young turtles are female. Due to the copious amounts of females, the turtles are quickly approaching extinction. They cannot reproduce because the majority of the population remaining are females, and therefore the species are
dwindling at rapid rates. Let’s take a look into their history of reproduction to gain more insight. Sea turtles account for a large part of our ocean’s biodiversity. The general mating period for sea turtles is concentrated around the months of March through October, depending on the specific species. In the northernmost regions of Australia, turtles have been observed nesting year long. In the southernmost regions, turtles have been observed staying closer to the typical range of months for nesting. Turtles are very connected to their place of birth; the females actually tend to lay their eggs on the same beach where they hatched. Turtles use their strong sense of surrounding involving ocean currents and magnetic fields within the ocean to direct them toward the path of their original hatching site. Throughout the duration of the nesting season, the females return to the nesting beach up to five times, each time laying up to one hundred eggs! These eggs have resided inside the turtle for a gestation period of about 6-10 weeks, sometimes as long as two years although it is rare. The mother sea turtle digs a small hole, not too far beneath the surface, to lay her clutch in. The eggs remain incubated underneath the sand for about 52 to 61 days, the longest ever recorded period being 70 days. Incubation lengths depend greatly on the temperature and weather conditions. For example, when the weather conditions present decent amounts of rain, incubation lasts longer. When the conditions are dry and arid, the incubation period is shortened. On average, approximately 70 to 140 babies are hatched from each nest. After creeping out of their shells, the new turtles sometimes take up to a full week to escape the depths of the sand. They emerge from the sand in the evening hours when the sky is dark, so there is a lesser chance of being eaten. Unfortunately, few of the new hatchlings usually survive the hike. Many are eaten by lurking predators waiting for their arrival. For those who do make it to the sea, the remainder of their life is spent solitary until the mating season comes again.