One of the largest kelp forests on Earth has been destroyed because of global warming.  From 2011 to 2013, the extreme marine heat waves have wiped out 100 kilometers of coastline in Australia’s Great Southern Reef according to research published Thursday in the journal Science.

The Great Southern Reef is located near the south coast of Australia.  It is an important ecosystem of interconnected temperate rocky reefs that covers 71,000 square km (27,000 square miles of Australia’s’ coastline.  The Great Southern Reef is the home for thousands of species of mollusks, fish, crustaceans, and other marine invertebrates. The reef also serves as a touristic place for fishing, scuba diving, and surfing, which contribute with $10 billion to Australia’s annual economy.

Scientists say about 35 percent of the coral in the northern and central parts of the Great Barrier Reef are dead or dying. Image credit: David Bellwood/ARC Centre of Excellence for Coral Reef Studies/AP.

Between 2011 and 2013, the Indian Ocean off Western Australia had the most higher sea temperatures ever recorded and a big part of the kelp forests – -were wiped out. This occurred due to global warming and La Niña weather phase. In 2011 sea surface temperatures reached 6°C a peak extremely high regarding the average temperature.

Between 2010-2013, 100 kilometers of kelp forest disappeared.

The high undersea temperatures brought about the loss of more than 100 kilometers of kelp forests which have been described as the fastest and extensive extinction ever recorded on planet Earth, according to Thomas Wernberg- a marine researcher from the University of Western Australia in Perth.  Wernberg, who had gone to the reef in 2010 and enjoyed observing the beautiful kelp forests, was completely shocked to see the destruction of such beautiful ecosystem.

“It was quite a shock to come back to these diving locations, and all of a sudden realize: ‘Wow – this is completely different,'” he says. “When we went up to the northern regions and saw that everything was gone, it was devastating.”

In 2013 three years after having gone to the Great Southern Reef, Thomas Wernberg and his friend Scott Bennett wanted to dive in that area as they did in 2010.  Back then, the duo had swum among a huge kelp forest and experienced the incredible sea life.  However, when they came back in 2013, they noticed that the kelps were no longer there.  At first, the duo thought they were not in the right location, but once they realized they were in the same spot as they were three years ago, they started to look for the kelps. Unfortunately, they did not find any trace of them.  They just found some species of seaweed, growing patchy, and low-lying lawns

For Bennett, being in a place entirely different was like someone used a bulldozer in the reef.  He says that this place was so empty like a brown moonscape underwater.

Map of the Great Southern Reef. Credit: Wernberg Lab

Climate change is the culprit of kelp forests destruction

Researchers say that climate change is the main responsible for such damage. They say that the temperatures underwater near Western Australia were already warm before the arrival of continuous series of extreme heat waves.  In 2011, the reef expected the highest temperatures ever recorded in 215 years.  Researchers said that kelps could not stand the extreme heat which resulted in their extinction in that area.

According to the research, until 2011, the kelp forest length reached 800 kilometers of Australia’s western flank, and it would cover 2,200 square kilometers. However, when the two biologists came back to the reef in 2013, they found that  43 percent of the sea forests, around 963 square kilometers (371 square miles), had been wiped out, including almost all the kelps that cover approximately 100 kilometers of Australia’s southern coastline.

The kelp never came back to this area after the heat waves. The research states that tropical species of fish went to the area to live in the warmer waters, including the grazing fish whose main diet is kelp. Therefore, what used to be the place for kelp forests, it is not anymore unless the temperatures underwater get low again. An ecosystem has been destroyed due to a “rapid climate-driven regime shift,”

Although Bennett and Wernberg are the lead authors of the research, they also worked with 21 other authors from other institutions in Australia and abroad. Adriana Verges and Alexandra Campbell two biologists at the University of New South Wales in Sydney believe that this study has alarming details of one of the most dramatic consequences of climate change. Campbell also said that kelp forests are not only disappearing in this particular area but also at similar latitudes on the east coast of Australia, which could be significant for the sea life and eventually for humans.

“Underwater kelp forests are like forests on land: they produce oxygen, they capture and sequester atmospheric carbon dioxide, and they provide food and shelter for a vast diversity of fish and other marine organisms,” she says. “Kelp forests receive far less attention than coral reefs, but that needs to change because they are extremely important – we all rely on them.”

Source: The Atlantic