The Leatherback's Role in Ecosystem (Niche)

1) Nesting and Reproduction
2) Diet
3) Importance to their Environment

 

 

 


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1) Nesting and Reproduction

Little is known about the ecology and life history of the Leatherback Sea Turtle, as it spends the majority of its life cycle at sea. Many male Leatherbacks only see the beach once in their entire lives, at the time of their birth when they make the treacherous journey out of the nest to the ocean waters (Cresli). Females come in contact with the beach as they are born, and will return only one more time (10-15 years later) to lay their eggs and create their nesting sites (Cresli). It is at these times during their reproductive activity on shore, that they are most easily studied. Coincidentally, it is these same experiences onshore that account for a large part of their destruction.

Leatherback Sea Turtles require clean and open beaches, which are often subject to erosion and hurricanes causing egg and nest loss, (Bagheera). The species has used the same nesting beaches for thousands of years, and as human population grows, they are becoming amongst the beaches most heavily used by people. Leatherback eggs have a substantial number of natural predators as it is. Humans only add to the disastrously delicate occasion which is reproduction. Over the 100 million years that Leatherbacks are thought to have existed, they developed a natural defense mechanism that has been adopted by many other species where offspring are in constant danger. Because Leatherbacks invest no parental care for their offspring, they have evolved to lay 100 to 150 eggs at a time (an example of overproduction of offspring) in hopes that their natural predators will not consume the entire nest and some the hatchlings will be able to reach the ocean to start their lives. Sadly, their defense is breaking down under pressure of heightened rates of human harvesting and disturbance of nesting beaches. In some places, nearly 100% of the eggs are harvested by humans immediately, and those that are left are obliterated by domestic dogs and pigs. Only a small percentage of the eggs laid will survive to grow to adulthood and breed. And while they are the favorite food for raccoons, seabirds, sharks and large fishes, they are also known for being a delicacy in Asia and the South Pacific.

Diet

Their primary source of food is the jellyfish which is thought to be because of their long and backward pointing cilia which aid in swallowing their soft and slippery food, (Cresli). They have also been known to feed on fish, mollusks, sea urchins and other marine creatures, (NOAA). Leatherback feces sink and drift towards the bottom of the ocean floor, where detritivores and bacteria feed and break the particles down into nutrients available for other organisms such as Elodea (and other plants) to take up and use.


http://www.seaturtles.org/images/photoarchive/photos/jelly3X5.jpg


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Importance to their Environment

All in all, Leatherbacks regulate invertebrate and jelly populations, as well as the populations of other primary consuming sea dwellers. Their eggs provide a staple food source for shore roaming animals. However, it is the excessive harvesting of eggs and exposure of nests by humans that has caused the plummet in Leatherback Populations. And so long as this disturbance of nests persists, there will be an unbalance and unharmonious flow of the food chain and food web concerning these organisms. Natural predators are expected and accepted in the environment of the Leatherback, but the intervention of humans and dismantling of what’s left of these nests is causing a negative and undesirable effect on this already delicate population of sea turtles.