Turtles have been around for over 200 million years, but their survival is now under threat. Of the seven species of sea turtles, six are on the International Union for Conservation of Nature's Red List of Threatened Species; this list is the most accurate indicator of the health of the world's biodiversity.
Turtles are called an indicator species because they provide vital insights into the health of complex marine ecosystems. Looking at it another way, conserving and preserving turtles has a direct impact on the lives of other marine creatures – and on the whole ocean system. Five of the seven species of sea turtles are found in the Indian Ocean, making Kenya a key conservation country.
Green turtles are Kenya's most populous residents, often spotted resting and relaxing on the reefs – and getting their shells cleaned by the ﬁsh. Their favourite foods are found in the sea grass beds in shallower waters where the waves break. Hawksbill turtles also hang out on the reefs, using their sharp beaks to break off pieces of sponge or coral and scraping algae from the rocks. Since their preferred diet is poisonous sponges, their meat is poisonous and people have died from eating it.
Turtles are reptiles, and need air to breathe. Female turtles can mate with several males, so one 'clutch' of eggs is fertilised by multiple males, increasing the genetic diversity of the offspring. They lay their eggs in a pit they've dug deep in the sand. Green turtles lay about 80-120 eggs in a clutch, Olive Ridley turtles lay about 100 while Flatback turtles lay around 50. When hatchlings break out of their shells, a yoke sac is still attached to them; it's this that gives them the energy to scramble to the surface of the sand and sprint for the sea. About half of all baby turtles perish within three days of hatching; only 1 in 1,000 survives.
The three main threats to turtles are plastic, poaching and ﬁshing. Plastic marine debris looks and smells like their food, particularly jellyﬁsh, causing turtles to ingest it or become entangled in it. Poaching is mainly for meat consumption. Fishing, especially industrial ﬁshing with trawlers or baited long lines, drags turtles down and drowns them. Ghost gear is also a threat for turtles. Abandoned or discarded ﬁshing nets travel huge distances on the ocean currents, trapping and killing large numbers of marine animals, entangling live coral, smothering reefs, and transporting parasites to new regions.
Another threat is climate change. Since the sex of the turtle is determined by the temperature of the sand in which it incubates – warmer sand forming females and cooler sand producing males – as the world's temperature rises, the number of female turtles will rise while that of males plummets. A study in Australia in 2017 found that in several nests, 90% of hatchlings were female.
Turtles live in all parts of our seas, including beaches, reefs, sea grass beds, lagoons and the deep dark depths of the oceans. If they disappear, it's a sign our oceans and everything in them are in grave peril.