threats from overfishing, pollution and climate change. Marine life plays an important role in maintaining the health of the world’s oceans. For example, mussels are the “engineers” of the marine ecosystem¹. They “clean” water by sucking it in and processing it. They do this to build up their body and shell, and at the same time excrete nutrients necessary for marine plants. Similarly, coral reefs, another vital marine species, are one of the major sources of nitrogen and other essential nutrients for innumerable organisms. And their demise could have dire effects on the entire marine food chain!
Sea turtles have their place in this delicate network of life-providing services as well. They are an irreplaceable organism to achieve the balanced ecosystem functioning, and yet, the population of these gentle creatures is threatened by commercial fishing, loss of the nesting habitat, as well as, climate change. There are 7 species of sea turtles that live in our oceans and 6 of those are classified as endangered or threatened by the International Union for the Conservation of Nature (IUCN). But did you know these 5 reasons why are sea turtles important for the ecosystem?
#1 Maintaining sea grass habitats
Sea grass beds are important feeding grounds for green sea turtles, manatees, dugongs, and other species. Besides, they are also nurseries for a variety of species of fish, shellfish and crustaceans. Sea turtles, manatees and dugongs, also known as herbivorous grazers, graze on the sea grass. This way they maintain the health of sea grass beds, and encourage its healthy growth and thickness.
#2 Enriching nesting beaches
Essential nutrients are introduced to the beach ecosystems, when female turtles lay their eggs on the beach². Sea turtles lay around 100 eggs in a nest and on average lay around 8 nests during the nesting season. The unhatched nests, eggs and trapped hatchlings are excellent sources of nutrients for the vegetation in the sandy ecosystem. When hatchlings emerge, they carry egg matter and nest organisms to the surface. This helps disperse nutrients to the small organisms in the beach sand which encourages vegetation growth.
#3 Providing habitat
Epibionts call sea turtles home. Epibionts are creatures which attach themselves to solid surfaces in the ocean such as crabs, whales, sea turtles and even floating debris. Researchers have found that more than 100 different species of epibionts live on the shells of loggerhead turtles! By taking such an efficient ride, epibionts get distributed to further locations across the ocean, which increases their survival rates. Although, some of them actually harm their generous host, others come with benefits for sea turtles as well³.
In the case of barnacles, it’s a little bit of both. Barnacles can form crusts over the turtle’s nostrils or eyes. But, they also provide convincing camouflage for their hosts. With enough barnacles, a sea turtle resting on the ocean floor can be indistinguishable from its surroundings³.
#4 Maintaining balance of the ocean floor ecosystems
Loggerhead turtles have large powerful jaws that allow them to feed on a prey with hard shells. They crush the shells and discard the pieces. This activity helps increase the rate at which the shells disintegrate, which boosts the rate of nutrient recycling and keeps the ocean floor sediments balanced.
When loggerhead turtles forage, their trails affect the compaction, aeration and nutrient distribution of the sediments on the ocean floor as well.
#5 Providing food for fish
Sea turtles function as a delivery boy for some fish and shrimp species. This is because they carry around barnacles, algae and epibionts. There are even special “cleaning stations” for sea turtles to visit, where they go to get their pampering treatment. Similarly like we do when getting a massage, turtles expose their bodies, stretching their limbs and raising their heads to allow other fish to pick the treats off their shells. This activity not only feeds smaller organisms, but also benefits sea turtles. When their skin and shells are clean, they have lower resistance while swimming.
As sea turtle populations decline, so does their ability to fulfill vital functions in the ocean ecosystems. Hence, it’s time for us to protect sea turtles and rebuild their populations to healthy levels as a vital step in ensuring healthy and resilient oceans for the future.