Turtles are one of our amazing sea species that everyone seems to love. But you always see them, or remember them swimming, and rarely ever eating. So you may be wondering, what do turtles eat in the ocean? Through this article we will highlight a sea turtles natural diet, and delve into the not so healthy alternative sea turtles are being confused by. So let’s begin.
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Did you know that all turtles originate from South Africa, from roughly 265 million years ago. This is where they are believe to have evolved from and now, you can find them in most oceans all over the world. Sea turtles travel thousands of kilometres as they migrate to feed and reproduce, often crossing entire oceans to tropical beaches to lay their eggs.
There are seven species of sea turtles that live in our oceans and Loggerhead turtles have one of the most amazing migrations. These specific species travel all the way from Japan and its surrounding countries, to California and Mexico to lay their eggs. Staggeringly this trip is over 10,000 kilometres.
What do turtles eat in the ocean – The 7 species
This species has a special appetite which changes as it grows into adulthood. Hatchlings and juveniles are Omnivores, which means they eat both animals and plantations. This is due to the fact they have to fend for themselves from the moment they hatch, so have to adapt to their surroundings.
Luckily for them, their mothers have chosen a perfect location with waters rich in plantations. Young turtles don’t have the skills, or the size they need to catch live foods. Once they reach adulthood, loggerheads will have mastered the skills they need to hunt crabs, whelks and conchs.
The green turtle is ironically named as it only eats greens. Thats right, this species of turtle is the only specie to be a herbivore as an adult. This means they only eat sea plants, foliage and marine algae. Green turtles are actually named ‘Green’ after the colour of their fat and cartilage. Not the colour of their shells like most people believe.
Hatched green turtles are in fact omnivores, feeding on small sea creatures. As they get older they will commonly find a coral reef to call home, feeding mostly on seagrass and algae.
On to the hawkbill’s which are know to be the fussiest eaters amongst the seven species. This is because they commonly only eat sea sponges. Sea sponges are living animals which can be found in sallow waters, coral reefs and even at the depths of the deep sea.
The hawkbills name comes from its hawk like beak, which is long, slightly curved and pointy. This makes for a great tool when digging into coral to find their beloved sea sponges.
Leatherback turtles are the only species thought to be something we call ‘Gelatinivores’. Gelatinavores are know to only eat gelatinous prey such jellyfish, tunicates and sea squirts. They are not known to eat any other foods apart from these.
Because of this gelatinous diet, leatherback turtles sometime misinterpret plastic waste in the sea for edible food. For this reason leatherbacks have become the most polluted species of turtle, due to eating human made plastic waste.
Commonly falsely categorised as carnivores, flatback turtles are in fact omnivores. Although mainly they chose to feed on jellyfish, sea cucumbers and soft coral, they will sometime feed in sea grass when food is scarce and hard to come by.
This specie of sea turtle is strictly carnivorous, with only ever meat on the menu. Usually found in the warmer shallow waters, Kemp’s Ridley turtles will dive down to feed on their preferred crab, but will eat other shellfish if crab isn’t available.
Unfortunately this species is the most endangered amongst the seven sea species. Not only is their nesting habitat being threatened, they are also at most risk from being caught in fisherman’s nets in the shallow waters.
The Olive Ridley is the worlds smallest sea turtle specie, commonly found in the tropical regions of the worlds oceans such as the Pacific, Indian and Atlantic oceans. They are mainly carnivorous, feeding on jellyfish, crabs, snails and shrimp, however they do occasionally eat algae, seaweed and sea grass also.
Plastic threats to a sea turtles diet
So what do turtles eat in the ocean? Plastic is being mass produced all over the world, and unfortunately is having an extremely harmful impact on our oceans and everything that lives within it. Unfortunately, sea turtles are taking the forefront of this, as they commonly falsely identify plastic waste for jellyfish. It’s thought that 52% of the worlds sea turtles have eaten plastic waste. A University of Tokyo study showed that Loggerhead turtles eat plastic roughly 17% of the time they come across it in our oceans. An even worse figure than that follows for the Green turtle species, which consume plastic up to 62% of the time they encounter it in our oceans.
Many sea turtle like to feed in shallow, food rich waters and coral reefs. Both of which are heavily populated with human interaction. What I mean by this is that people travel from all over the globe to dive and snorkel in the worlds coral reefs. And with human interaction comes pollution. Sometimes purposefully, and sometimes not, plastic waste finds its way into the sea. Mainly wrapping from food and drink products.
Where the problem starts
The problem starts with plastics life span. Obviously plastics aren’t actually alive, but I mean in relation to the time it takes for plastic material to decompose in sea water. And it varies for many different products of plastic waste.
For example a plastic bag is estimated to tale 20 years to decompose in sea water, whilst plastic. Bottle can take up to 450 years to fully decompose. The most outrageous is fishing lines, estimated to take up to 600 years to decompose in sea water. Plastics will do hundreds of laps in the oceans cycle, continuously circling round for all these years. Even once these plastic have decomposed there’s no telling if little fragments will still pollute the oceans. It’s still too early to us to say.
Not only do sea turtles eat the plastic waste, they can also get caught up in it and drown. Fishing lines, fizzy pop and beer can ringlets are the main culprits for this. Old fishing lines which are thrown overboard create a huge threat to turtle as they get tangled and cannot untangle themselves to come up for air. Horribly this usually ends in the turtle drowning, caught up in a human made product.
What do turtles eat in the ocean – The effects of eating plastic waste?
It goes without saying that eating plastic has its dangers. This goes for every living species on this planet. But unlike the human species, which has developed ways to deal with certain situations involving plastic, turtles struggle immensely.
Up to 25% of sea turtles that each a singular piece of plastic ends in death. Some plastics are extremely sharp and can severely damage internal organs. It can painfully slice and pierce through fat and muscle and somethings the turtles organs themselves.
Pieces of plastic bag commonly clog the turtles intestines. This means that any suitable foods which is does eat, now can’t pass through the intestines, resulting in the turtle not being able to feed. Ultimately this ends in a turtle which is starved to death.
Eating plastics causes a a turtle to become more buoyant, specially if they ingest a lot of it. Plastics naturally float in water, albeit usually under the waters surface. But nevertheless, it floats. Every time a sea turtle eats a piece of plastic its buoyancy naturally increases. This increases a turtles ability to dive down to the sea bed to hunt for food. It will take a lot more energy for them to dive down to the depth they need in order to feed on the correct diet.
When ingested, plastic waste releases harmful toxins into a turtles body. These toxins are primarily transported around the body through the oxygenated veins, and are known to stunt a turtles fertility.
We hope this has answered all the questions you may have had on “what do turtles eat in the ocean”. The seven sea species all have a very different dietary requirements which is why they can be found in most oceans across the world.
Unfortunately sea turtles do feed on harmful man made products which are polluting our oceans. But with this new information, hopefully you will think twice about how you dispose of your waste and sea turtle species will become less endangered and vulnerable to plastic waste in our oceans.