How dolphin poop could help save damaged coral reef

By Mark Waghorn via SWNS

Coral reefs could be saved by dolphin POO, according to a new study.

Many reefs are turning white because of the warming seas.

But the marine mammals' excrement contains vital nutrients that help them recover, say scientists.

Study lead author Dr. Tom Letessier, of the Zoological Society of London (ZSL), said: "Coral reefs are facing profound threats around the world, including climate change and biodiversity loss.

"But this research has identified a clear ally for them - spinner dolphins."

The finding is based on more than three decades of data collected in the Indian Ocean - some during whale watching trips from the Maldives.

Dr. Letessier said: "By analyzing over thirty years of visual observations of spinner dolphins as well as 6 months of acoustic recordings, we confirmed this species are daily commuters from offshore areas to shallow water.

"Dolphins are deep feeders, but come back to sheltered lagoons to rest which is when they deposit around half of their crucial, nutrient-rich excrement."

Coral reefs are notoriously poor in nitrogen and phosphorus.

The key elements are essential for photosynthetic plants that provide their foundations.

Dolphin poo, on the other hand, is rich in nutrients.

Dr. Letessier said: "Simply by going to the toilet in the shallow atoll lagoons, these dolphins are providing a vital nutrient supply for the corals - making the strongest possible case for protecting the dolphins in order to save these reefs."

The 'jungles of the ocean' are among the most diverse ecosystems on the planet.

They boost economies by attracting holidaymakers - underpinning the livelihoods of six million people around the world.

They also protect against waves, storms and flooding - which are becoming more frquent due to climate change.

Corals are struggling worldwide - including Australia's Great Barrier Reef.

The natural wonder of the world - the largest living structure on Earth - has more than halved in size since 1995.

When under stress, corals expel the algae that produce their vivid hues - a process known as bleaching.

Dolphins also face a range of threats to their survival - such as overfishing, say the British conservationists.

Co-author Dr. Charles Anderson, who is stationed in the Maldives, said: "Spinners are the super-abundant dolphins of the tropical Indian Ocean.

"Although well protected in the Maldives and the Chagos Archipelago, they are subject to high levels of bycatch in gillnet fisheries elsewhere in the region.

"This study demonstrates their potential importance to the health and resilience of coral reefs.

"It underscores the need for improved conservation of cetaceans and management of fisheries across the Indian Ocean."

The study found they play a vital role in supporting struggling coral reefs across the Chagos Archipelago - about 1,000 miles south off the coast of India.

It is estimated the amount of nitrogen they take in during their daily commute boosts productivity and resilience.

The dolphins enter shallow lagoons in the morning where they then spend half the day resting.

Then they leave in the afternoon - to hunt and forage in deeper waters at night.

Metabolic models showed one individual pod would produce around 635lbs of nitrogen - equivalent to four average humans in weight.

In the clear waters of the Maldives - where clear, pristine ocean is often seemingly unproductive - coral reefs are critical for the local economy.

Spinner dolphins are the most abundant cetacean. The nocturnal creatures prey on the staggering number of small creatures that migrate up from 200 to 1,000 metres below the surface.

Dr. Letessier added: "These nutrients are important for coral reefs which are threatened by coral bleaching and other stressors.

"It is exciting to have found a likely important mechanism by which the dolphin's behaviour could be sustaining the health of surrounding reefs.

"This study is just the first piece in a bigger puzzle which we will explore further as part of our new regional scientific cetacean project."

Spinner dolphins are highly dependent on shelter for resting and strongly associate certain behaviors with certain times of the day.

They are very sensitive to human disturbance. Legislation and local fishing practices that use pole-and-line rather than nets have helped them thrive.

Corals are living, 'breathing' animals - despite having plant characteristics and looking like rocks.

They absorb oxygen and release carbon dioxide through their outer layer.

They are relatives of jellyfish and anemones. There are more than 800 known species of reef-building coral. The study is in the Journal of Zoology.