Endangered green turtles play role as gardeners of seas

Extinction does not threaten sea creatures thanks to the way green sea turtles prune sea meadows, a source of oxygen in the seas, Sea Turtle Research, Rescue and Rehabilitation Center (DEKAMER) Director Professor Yakup Kaska has told state-run Anadolu Agency.

For this reason, green sea turtles, which are the only herbivorous species of sea turtle, are said to play a key role as “gardeners of the seas” in the marine ecosystem around the coast of the southwestern province of Muğla.

However, the green turtle is also listed as “endangered” by the International Union for Conservation of Nature (IUCN) and the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), and is protected from exploitation in most countries.

Kaska, an academic at Pamukkale University, said Turkey hosts the most important turtle nesting areas in the Mediterranean.

“Although an estimated 200,000 female turtles nest every year in the world, only 500 to 800 nest in the Mediterranean. In this respect, the situation for the Mediterranean population of the green sea turtle is of utmost importance, and Turkey must act to ensure the survival of the species,” he added.

Kaska said the turtles’ way of “gardening” helps every living creature in the sea, with seagrass meadows producing oxygen for all creatures.

“Green sea turtles feed on seagrass meadows. This kind of feeding is very important for the sea flora and creatures. These meadows are the oxygen storage tanks of the seas and green sea turtles prune them. In this way, fish eggs and other creatures find a place to hide,” he said, referring to way the turtles bite off the tips of the blades of seagrass, which keeps the grass healthy.

“Other sea turtles feed on meat but green sea turtles are vegetarians. If sea meadows and green sea turtles
are not protected, all creatures risk extinction,” Kaska also said.

“Sea and land are like two scales of the same balance. While food constantly flows from land to sea through rains and floods, the sea turtles allow movement from sea to land, which keeps the scale in balance. Like gardeners who work for free, they prune the seagrass meadows,” he added.

In order to prevent damage to seagrass meadows, which typically grow in shallow, coastal areas, Kaska recommends that boats anchor to floating water gages instead of casting their anchors down into the seagrass meadows below.

DEKAMER Project Assistant Ayfer Şirin stated that many people wrongly believe that the herbivorous feeding habits of green sea turtles harms the sea meadows.

“Just as we cut the grass in our garden to make it grow again, so too do green sea turtles garden the seas. If we want to protect the seagrass meadows, which provide a vital source of oxygen in
the seas, we need to protect the green sea turtles too,” Şirin said.

The generally long and narrow seagrass leaves often grow in large meadow-like formations, which resemble terrestrial grasslands.

Because seagrasses produce their own food through photosynthesis, they are generally limited to growing in shallow and sheltered coastal waters anchored in sand or mud bottoms. Most species complete their entire life cycle underwater.

Producing their food through photosynthesis provides the oceans with oxygen and nutrients while their meadow-like growing areas give many species of fish a place to hide their eggs. Seagrass meadows grow in the Aegean and Mediterranean coasts of Turkey.