'Gut-wrenching': Kayakers shocked after finding 'graveyard' on island

WARNING - CONFRONTING IMAGES: At first glance it’s hard to identify the dead creatures captured in a series of photos lying across a sandy estuary in Florida.

Taken during a kayaking trip across the Indian River Lagoon Estuary (IRL) on February 27, the animals' bones and rotting flesh are being scavenged by vultures.

As the journey came to an end, participants had been advised they may wish to avoid the particular 100 metre stretch of shoreline where the animals lay.

Despite the warning Merritt Island resident Philip Stasik, and his wife, Linda, ventured on and what they found was "gut-wrenching".

“We didn't go there because of morbid curiosity or whatever,” Mr Stasik told Yahoo News Australia.

“Sometimes there were bad things and you have an obligation to see them to go as a witness."

What they saw is the result of a growing environmental disaster that is seeing the US state’s manatees die in record numbers.

The photos show a cluster of 13 individual animals, decaying on the west side of Merritt Island, north of Manatee Cove Park.

Large numbers of manatees are washing up across Merritt Island, some found in residential areas are dragged out to remote locations by authorities, while others are beached via the currents.

No matter how the animals Mr Stasik photographed arrived on shore, they are the sign of an ongoing environmental disaster.

'Almost no vegetation left': Manatees starving across Florida

Florida’s entire manatee population is estimated to be between 5000 and 7000, and 432 of them are confirmed by authorities to have died this year.

Dr Martina de Wit is working with Florida Fish and Wildlife Conservation (FWC) to better understand the event.

Having worked with manatees for 15 years, Dr de Wit says she’s never seen the animals in such poor shape.

She describes lactating females who should be nursing their young as coming in looking like “empty bags”.

“The problem is that the seagrass in this lagoon has has been in trouble for years now,” Dr de Wit said.

“But it appeared that this year, there's almost no vegetation left for them to eat.”

While the ongoing deaths are still under investigation, the majority of necropsies they have completed point to starvation.

'Train wreck': Public up in arms over manatee deaths

Manatee malnutrition is directly linked to algal blooms which are killing off their food source - sea grass.

Despite the average depth of the estuary being just over a metre, the algae is so thick that the light can’t penetrate to the bottom, and this stops the grass from photosynthesising.

Dr Leesa Souto from the Marine Resources Council said local residents are upset as dead manatee continue to wash up.

“If you live along the lagoon, you've seen a dead rotting manatee in your backyard,” she said.

“It's just ridiculous, so the public are up in arms.”

Struggling to find food, manatees have been venturing away from warm springs and into cooler waters during Winter.

This is stretching their biological capacity further and resulting in them dying of cold stress which is exacerbated by starvation.

“We've just been watching this train wreck, we’ve been trying to figure out what else can the manatees eat,” she said.

“We’ve seen them haul themselves up on grass, onto people's lawns and start eating the shrubberies and grass on people's residential lawns."

Dr Souto describes the IRL as once the most biodiverse estuary in the United States, however human impact has changed that.

The first algal “super bloom” occurred in 2010, destroying approximately 67 per cent of the sea grass, but an even bigger one occurred in 2016. Now 95 per cent of the sea grass is gone.

• Dolphin activist Ric O'Barry reveals scene that still haunts him

• Sea Shepherd founder warns destruction of planet 'out of control'

• Gas project will destroy sacred site, Indigenous elders fear

Dr Souto said state agency supplied ambient water quality monitoring shows the trend line has stayed the same over the last 25 years, meaning aside from the blooms, there have not been any “significant changes”.

What scientists do know is that in 2010 the balance of nitrogen and phosphorus flipped, but understanding which particular nutrient is fuelling the algae bloom will be key to the survival of manatees in Florida.

Carers need to increase capacity as numbers of sick expected to increase

Save the Manatee Club’s Executive Director Patrick Rose identifies drain fields, septic tank sewage and fertiliser runoff from over-development as major contributors to the algal blooms.

His team have been caring for manatees as part of the Manatee Rehabilitation Partnership which sees FWC biologists work alongside welfare groups.

They have cared for over 50 manatees this year, and Mr Rose expects number to increase, beating the 150 they saw last year "by a lot".

As the weather warms, malnourished animals will still be susceptible to boat strikes and other causes of harm, and in order to admit those extra patients, Save the Manatee Club will have to find a way to increase capacity.

“They need our help and we need to be their voice for protection,” Mr Rose said.

“They're just slow moving, have a low metabolic rate. They evolved with no natural enemies and didn't need to have strong defences.”

Climate change expected to further impact manatees

Greenpeace fear that climate change will only to add to manatee welfare challenges in the coming years, adding to a deadly cocktail of algal blooms and unsustainable development.

Extreme weather will likely put further pressure on the increasingly frail animals.

The charity's US oceans campaign director John Hocevar said he could see manatees were already in trouble in the nineties when he was studying marine biology in South Florida.

"Unless we get serious about addressing the root causes, we are going to lose manatees - as well as coral reefs and a lot more," Mr Hocevar said.

"There are a lot of factors contributing to this tragic manatee die off, but the common thread is that humans are responsible for all of them," he added.

Humans showed the brilliance of their ingenuity in the 1960s when they first rocketed to the moon from the Kennedy Space Centre, which is located on Merritt Island.

Back on Earth, scientists are working hard to find a solution to Florida's dying estuary, a problem created by placing our own advancement ahead of all other species.

Do you have a story tip? Email: newsroomau@yahoonews.com

You can also follow us on Facebook, Instagram and Twitter and download the Yahoo News app from the App Store or Google Play.