Scientists have been able to discover the world's largest known seagrass ecosystem in the Bahamas with the help of tiger sharks.

The researchers attached cameras and trackers to the dorsal fins of tiger sharks for their experiment. The data and footage collected with the help of these sharks helped them measure the extent of seagrass meadows in the Bahamas.

Tiger sharks are a fierce species. They were chosen for the study due to their highly consistent associations with seagrass ecosystems.

Scientists carried out as many as 2,542 individual surveys of the ocean floor to gauge how far stretched the meadows are, according to the study published in Nature Communications.

They found that 42% of it had dense seagrass meadows, 36% had sparse seagrass cover, and 22% did not contain seagrass. The seagrass ecosystem stretched across up to 92,000 sq. km (35,000 sq. miles) of the Caribbean seabed. The global seagrass coverage now stands at more than 40%.

"This finding shows how far are we from having explored the oceans, not just in the depths, but even in shallow areas," said the report's co-author, Professor Carlos Duarte.

Mapping seagrass meadows is an expensive and logistically challenging task since they need to be "ground-truthed," which implies that they need to be confirmed by someone at the site. And this is why the scientists used tiger sharks for this study.

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Tiger sharks are highly mobile animals and can access significant depths. They also spend a lot of time swimming through seagrass covered areas. The scientists fixed cameras and radio tags on seven sharks between 2016 and 2020. The data collected with the help of these seven sharks is what helped scientists find the meadows.

Seagrass is the foundation of key coastal ecosystems but have waned globally for the last few decades. They are also an important part of the sharks' diet.

Boating, fishing, and coastal development are some of the factors that have proven to be threats to seagrass existence. According to a report in The Guardian, the UK has already lost 90% of its seagrass meadows in the last few centuries.

Seagrass (Posidonia oceanica)
The oldest living thing on Earth has been identified as a self-cloning sea grass in the Mediterranean. The sea grass was found to be between 12,000 and 200,000 years old and was most likely to be at least 100,000 years old. Sea grass meadows can be composed of ancient giant clones - organisms stretching up to nearly 10 miles wide. Commons.Wikimedia.com
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