by The turquoise water of Hōnaunau Bay in Hawaii, an area that is popular with snorkelers and divers, is teeming of spiky creatures that threaten to push the coral reef ‘past the point of recovery’, has found new research.
Sea congest numbers here explode such as the fish species that usually keep their populations in control as a result of overfishing, according to the study, published last month in the magazine Plos One. It is another blow to a reef that is already damage to suffering due to pollution and climate change driven ocean waves and sea level rise.
Kelly J. van Woesik, a researcher at the North Carolina State University Center for Geospatial Analytics and a study author, noted for the first time an unusually high numbers of sea cones on snorkeling. “I knew there was a story to tell,” she said.
She and her colleague researchers used data from diving investigations and images from the air to follow the health of the reef.
“We have found an average of 51 urchins per square meter, one of the highest registered densities on coral reefs around the world,” said Van Woesik.
Echinometra Mathaei, the most common species at sea in Hōnaunau Bay. Hourchins erode the reef. – Kelly van Woesik
Sea cones are small invertebrates, characterized by their spiky bodies and found in oceans around the world. They play a useful role in preventing overgrowth of algae, which can suffocate oxygen to coral. However, they also eat the reef and too many of them can cause harmful erosion.
In Hōnaunau Bay, the coral is already struggling to reproduce and grow because of the ocean heat and water pollution, making it even more vulnerable to the erosion inflicted by the sea cones.
The growth rate has fallen according to the study.
Rifgrowth is typically measured by the amount of calcium carbonate – the fabric that forms coral frame – it produces every year per square meter.
The Rif in Hōnaunau Bay grows 30 times slower than four decades ago, according to the study. The production levels were approximately 15 kilograms (33 pounds) per square meter in parts of Hawaii, which indicated a healthy reef, according to research in the 1980s.
Nowadays the Rif in Hōnaunau Bay only produces 0.5 kg (1.1 pounds) per square meter.
To compensate erosion of hedgehogs, at least 26% of the reef surface must be covered by living corals – and even more coral cover is needed to grow.
Reefscape of living and dead big corals in Hōnaunau Bay, Hawaii. – Greg Asner
Gregory Asner, an ecologist at Arizona State University and studies the author, said what happened in this part of Hawaii, was symbolic for the increasing pressure on reefs throughout the region.
“For 27 years I worked in Hōnaunau Bay and other bays such as it in Hawaii, but Hōnaunau stood out early as an iconic example of an rif threatened by a combination of pressure,” he said, with reference to heating oceaning temperatures, pollution by tourism and heavy fishing.
The implications of coral collection are far -reaching. Coral reefs are sometimes called the “rainforests of the sea” because they support so much ocean life. They also play a crucial role that protect coastlines against storm floods and erosion.
“If the reef cannot keep track of the rise in sea level, it loses its ability to limit incoming golf energy,” said Van Woesik. “That increases the erosion and flood risk of coastal communities.”
Kiho Kim, a professor in environmental science at American University, who was not involved in the study, said that the findings emphasize the vulnerability of rifecosystems under stress.
“Dramatic increase in each species indicates an unusual state that has enabled them to spread,” said Kim. This imbalance can undermine the diversity and reduce the ability of the reef to offer essential ecosystem services, including food security and carbon storage, he told CNN.
Despite the challenges, researchers emphasize that the future of the reef has not been sealed. Local groups in Hōnaunau work to reduce fishing pressure, improve water quality and support coral recovery.
“These reefs are essential for protecting the islands they surround them,” said Van Woesik. “Without action that is being taken now, we run the risk of allowing these reefs to erode the point of no return.”
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