indian ocean

Deeper corals bleaching

December 7, 2023 By EarthWise Leave a Comment

When ocean waters get too warm, corals – which are actually tiny animals – eject the colorful algae that inhabit their tissues. The symbiotic relationship between coral polyps and algae is essential to coral survival When the algae is ejected, previously colorful coral turns white, and the coral can ultimately die. If waters cool off, the algae can reestablish themselves and the coral can regain its color and health.

The world’s oceans have been warming at an unprecedented rate, making coral bleaching and die-off a global phenomenon. It is estimated that half of the planet’s reefs have already disappeared. Some places are worse off than others. For example, almost 95% of coral reefs in Southeast Asia are threatened. Florida’s reefs are especially threatened, particularly since there have been unprecedented marine heatwaves off its coast.

It has long been assumed that deeper reefs, where water is cooler, would remain safe from the effects of warming, but a few years ago researchers recorded coral bleaching some 300 feet underwater along the Egmont Atoll in the western Indian Ocean. At one point, bleaching affected 80% of corals in some areas. This discovery came as a huge surprise to oceanographers. It was probably associated with an El Niño-like phenomenon in the waters and those reefs have mostly recovered in the intervening years.

Fairly recently, researchers have found pristine coral reefs deep down in the waters off the Galapagos Islands, where shallow reefs have largely disappeared. There are likely to be similar reefs in the ocean depths around the world, but scientists are expressing concern that even coral reefs lying deep beneath the ocean surface may not ultimately be protected from the warming seas.

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As Oceans Warm, Coral Bleaching Seen at Greater Depths

Photo, posted June 5, 2023, courtesy of Ryan Hagerty / USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Rising Seas In The Maldives | Earth Wise

May 24, 2021 By EarthWise Leave a Comment

The Republic of Maldives is an archipelago in the Indian Ocean, southwest of Sri Lanka and India and about 400 miles from the Asian mainland. It is one of the world’s most geographically dispersed sovereign states, the smallest Asian country by land area, and, with a little over 500,000 inhabitants, the second least populous country in Asia. With its spectacular scenic beauty, it is also a premier tourist attraction.

With more than 80% of its 1,190 coral islands standing less than 1 meter above sea level, the Maldives has the lowest terrain of any country in the world. As a result, the Maldives is particularly vulnerable to the sea level rise associated with climate change.

Some studies predict a grim future for the Maldives as well as other low-lying islands. One study concluded that the islands could become uninhabitable by 2050 as wave-driven flooding becomes more common and freshwater becomes limited.

The Maldives government has explored plans to purchase land on higher ground in other countries. Planners are also working to enhance the resilience of the country’s current islands. An example is Hulhumalé, a newly constructed artificial island northeast of the country’s capital, Malé.

Construction of Hulhumalé began in 1997 and it now covers 1.5 square miles, making it the fourth largest island in the Maldives. Its population is now more than 50,000, with more than 200,000 expected to eventually move there. The new island, built by pumping sand from the seafloor onto a coral platform, rises about 2 meters above sea level. The extra height could make the new island a refuge for Maldivians driven off lower-lying islands by the rising seas.

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Preparing for Rising Seas in the Maldives

Photo, posted June 15, 2009, courtesy of Elena N via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Hot Year Continues | Earth Wise

December 8, 2020 By EarthWise Leave a Comment

The National Oceanic and Atmospheric Administration’s monthly global climate report for October reports yet another month of high temperatures. October 2020 was the fourth-hottest October on record, continuing the pace for the year to be the second hottest on record.

The 10 warmest Octobers have occurred since 2005 and the seven warmest have all occurred in the last seven years. Europe had its warmest October ever, surpassing the previous record set in 2001.

For the year to date, the global temperature was a full degree Celsius (or 1.8 degrees Fahrenheit) above the 20th century average. This was just 0.03 Celsius degrees lower than the record set in 2016. Europe and Asia have had their warmest year-to-date period on record.

Other notable observations in the report included that Arctic sea ice coverage was almost 37% below the 1981-2010 average and was the smallest October coverage on record. The previous record was set last year.

Heat records were set around the world including parts of the northern and western Pacific Ocean, southern North America, South America, eastern Europe, the northern Middle East, the eastern Mediterranean Sea, southern Asia, and in small areas across the Indian and Atlantic Oceans.

Despite the record global temperatures, the Northern Hemisphere’s snow coverage in October was the 10th largest over the past 53 years. The snow coverage in North America was the largest on record for October.

Adding in the extremely active hurricane season, with 12 hurricanes and 29 tropical depressions, weather around the world continues to be anything but typical.

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Remarkably warm October fuels march toward 2nd-hottest year

Photo, posted February 8, 2016, courtesy of Jasmin Toubi via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Cost of Cleaning Up Ocean Plastic | Earth Wise

October 7, 2020 By EarthWise Leave a Comment

Small island developing states increasingly find themselves with large amounts of plastic waste. A recent study looked at the financial cost for removing it.

Aldabra Atoll is a UNESCO World Heritage Site in the Seychelles. It is the world’s second-largest coral atoll and is the home of 307 species of animals and plants, including the largest population of giant tortoises in the world. Aldabra has been called one of the wonders of the world and one of the crown jewels of the Indian Ocean.

Last year, a team from the University of Oxford and the Seychelles Island Foundation, spent five weeks removing litter that had washed up on Aldabra’s shores. In total, they removed 25 tons of plastic litter which, to their surprise, was dominated by waste from the fishing industry. The researchers now estimate that over 500 tons of litter remain on the island, 83% of which consists of buoys, ropes, nets, and, of all things, over 300,000 individual flipflops. This is the largest accumulation of plastic waste reported for any single island in the world.

According to the study, the cost to clean up the entire island would be nearly $5 million, requiring 18,000 person-hours of labor. A project of this magnitude is beyond the capacity of non-profit organizations like the Seychelles Islands Foundation.

The plastic pollution in Aldabra is related to the fishing industry in Seychelles, which provides tuna to high-income markets around the world. The research highlights how even remote highly protected island ecosystems are impacted by global pollution and how difficult and costly it is to remedy.

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Millions of dollars to clean up tuna nets and flip flops from island state

Photo, posted December 27, 2016, courtesy of David Stanley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Making Roads From Ocean Plastic

June 7, 2019 By EarthWise Leave a Comment

Like many other places around the world, India has a big problem with plastic waste. Its 1.3 billion people each use an average of 24 pounds of plastic per year and much of it ends up in the Arabian Sea and Indian Ocean.

Fishermen in India’s southern state of Kerala have taken on the battle against plastic waste in the ocean by launching a campaign called Suchitwa Sagaram, or Clean Sea, in which they are collecting the plastic and bringing it back to shore.

In the first 10 months of the program, fisherman have removed 25 tons of plastic from the Arabian Sea. Once the plastic waste reaches shore, it is fed into a plastic shredding machine. As is the case for many of India’s plastic recycling schemes, the shredded plastic from the sea is converted into material that is used for road surfacing.

There are more than 20,000 miles of plastic roads in India, mostly in rural areas. In fact, more than half the roads in the southern state of Tamil Nadu are plastic. Such roads have become popular because they are more resilient to India’s searing heat. The melting point of plastic roads is around 150 degrees Fahrenheit as compared to 122 degrees for conventional roads.

Roads made from recycled plastic are also cheaper than ones using conventional plastic additives. A mile of plastic road uses the equivalent of a million and a half plastic bags and saves about a ton and a half of asphalt. Overall, plastic roads are about 8% cheaper than conventional roads and create jobs for people in the fishing communities.

India’s plastic roads are a promising way to fight the problem of ocean plastic pollution.

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