Latest news with #seaurchins
Yahoo
05-07-2025
- Science
- Yahoo
Devastating change taking place at Australia's 'best beach': '20 million of them'
It was voted as Australia's Best Beach a few short months ago, but under the surface a dark shift is taking place. An army of invaders is turning the sea bed into a barren wasteland, and experts fear the threat could destroy up to 50 per cent of reefs along the state's coastline if more isn't done to stop it. In February, a stretch of beaches along the famed Bay of Fires on Tasmania's east coast was awarded the title of the best beach in the country. But Dr John Keane, a fisheries research fellow at the Institute for Marine and Antarctic Studies, says underneath the surface it's a different story. Longspined sea urchins, also known as centro from their scientific name centrostephanus rodgersii, have arrived in Tasmania's oceans in droves. Dr Keane estimates the population has grown to more than 20 million. "What makes them so damaging is they've got a very broad spectrum of diet," he said. As well as targeting lush kelp forests, they also eat sessile invertebrates like sponges, corals, anemones and sea squirts. "They basically eat anything on the reefscape and they leave that barren rock that can extend for kilometres." The urchins have been found all the way down the state's east coast, reaching as far south as Port Arthur. Several climate factors are working together to draw the urchin larvae further south than ever before. Tasmania's waters are warming at a rate of twice the global average, according to the CSIRO. The East Australian Current is extending further south, pushing warmer water towards Tasmania. Combined with the general warming of climate change, it's creating a "double effect", Dr Keane said. This creates an environment suitable for the centro to thrive – and take over. Dr Keane believes harvesting urchins is a viable solution, as the buttery golden roe is considered a delicacy and can sell for more than $500 per kg. Up until recently, 500 tonnes of centro were being harvested every year and some sites were seeing a successful decline in numbers alongside the return of kelp. While it was a win for the environment, it was also a win for the Tasmanian economy. The fledgling industry has created jobs in multiple areas, injecting revenue into the state and adding a new taste to Tasmania's already impressive spread of local flavours. Recently, the efforts to manage the urchins have slowed down after the closure of one of the state's major processing facilities. Dr Keane said the company was harvesting around 400 tonnes of centro annually – about 80 per cent of state's collective total – which has left a hole in the market. While smaller businesses are trying to fill that void, they don't have the capacity to handle the same volume of urchins. "There are plenty of divers wanting to go catch these sea urchins. But there's not the market and the processing capacity to be able to do that at the moment," Dr Keane said. Because the catches have declined, data is now showing evidence of the urchin population growing. "The other option is to go out there and kill them without processing, which can be done and it's quite effective, but it's highly expensive," he added. If no control measures were in place, Dr Keane estimates 50 per cent of Tasmania's reefs would barren in 10 years. He's hopeful that change is coming, and the biggest difference could be made through government support. "We need funding to support the industry. That's the solution," Dr Keane said. "Temperate reefs just aren't as sexy as tropical reefs. The Great Southern Reef gets 1 per cent of the funding that the tropical reefs do. "It just doesn't have that iconic image of snorkelling on a coral reef. All the tropical fish. Even though temperate reefs have some amazing biodiversity and kelps and sponge gardens and it's so beautiful, it just doesn't get the light of day, unfortunately." Tasmanians will head to the polls in a matter of weeks for the state election, with Dr Keane reminding residents that change begins with a vote. "If we don't get this fishery up and running, we're just going to continue to lose more reefs, and then that all negatively impacts other commercial fisheries such as rock lobster and abalone, it'll impact tourism, and impact biodiversity and the environment more generally." Do you have a story tip? Email: newsroomau@ You can also follow us on Facebook, Instagram, TikTok, Twitter and YouTube.
Yahoo
30-06-2025
- Science
- Yahoo
Grim underwater find prompts calls to make $43.9 million change in Aussie waters
Sea urchins are being found in alarming numbers in waters surrounding one of Australia's largest cities, but researchers believe culling them could create $92 million in benefits. A team from RMIT believe multiple industries could benefit if Port Phillip Bay's kelp forests they're destroying, are allowed to recover. Sea urchins are native to waters around Melbourne and feed on kelp, but warming waters and changing ocean currents have caused their numbers to reach 'unsustainable population levels', and pictures taken by RMIT divers show things are looking grim in many parts of the ocean. Kelp coverage in the greater region has declined by up to 98 per cent in the region over the last 40 years. Because the changing ocean conditions that favour the urchins are caused by climate change, their numbers aren't expected to naturally correct themselves, which is why the researchers argue intervention is needed. The study found that reducing urchin numbers and allowing the kelp forests to recover would reduce nitrogen and phosphorus in the water. Carrying out the plan would be expensive, with an investment of $43.9 million needed to create $92.1 million in benefits. But the study's lead author, Dr Paul Carnell, argues the plan would be a 'smart economic investment' for government. 'This approach can be targeted to specific areas of the bay, so we can get the greatest bang for our buck,' he said. 🪨 Inventor's valuable secret hidden beneath pile of rocks in outback 📸 Rare colour footage of extinct Australian animal seen again after 90 years 📍 Huge change to multi-million dollar block of land in busy suburb The plan could see the tourism sector profit as kelp forests are a drawcard for divers and snorkellers. Fish stocks would also likely improve, aiding both commercial and recreational fishers. But the biggest beneficiary would likely be the wider environment, as kept forests play an important role in water purification and carbon sequestering, a major cause of global warming. In Victoria, the collection of urchins is regulated, and there is a bag limit of 40. While they're in problematic numbers, they are actually a valuable resource and considered a delicacy in some Asian cultures. In Australia, some premium urchin roe can retail for almost $700 for 120 grams, but there are cheaper alternatives for as little as $60 per 100 grams. The study has been published in the journal published in Ecosystem Services. Love Australia's weird and wonderful environment? 🐊🦘😳 Get our new newsletter showcasing the week's best stories.
Yahoo
22-06-2025
- Science
- Yahoo
An explosion of sea urchins threatens to push coral reefs in Hawaii ‘past the point of recovery'
The turquoise water of Hōnaunau Bay in Hawaii, an area popular with snorkelers and divers, is teeming with spiny creatures that threaten to push the coral reef 'past the point of recovery,' new research has found. Sea urchin numbers here are exploding as the fish species that typically keep their populations in check decline due to overfishing, according to the study, published last month in the journal PLOS ONE. It's yet another blow to a reef already suffering damage from pollution as well as climate change-driven ocean heat 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, first noticed unusually high numbers of sea urchins on snorkeling trips. 'I knew there was a story to be told,' she said. She and her fellow researchers used data from scuba surveys and images taken from the air to track the health of the reef. 'We found on average 51 urchins per square meter, which is among the highest recorded densities on coral reefs anywhere in the world,' van Woesik said. Sea urchins are small marine invertebrates, characterized by their spiny bodies and found in oceans around the world. They play a useful role in preventing algae overgrowth, which can choke off oxygen to coral. However, they also eat the reef and too many of them can cause damaging erosion. In Hōnaunau Bay, the coral is already struggling to reproduce and grow due to ocean heat and water pollution, leaving it even more vulnerable to the erosion inflicted by sea urchins. Its rate of growth has plummeted according to the study. Reef growth is typically measured by the amount of calcium carbonate — the substance which forms coral skeletons — it produces per square meter each year. The reef in Hōnaunau Bay is growing 30 times more slowly than it did four decades ago, according to the study. Production levels were around 15 kilograms (33 pounds) per square meter in parts of Hawaii, signaling a healthy reef, according to research in the 1980s. Today, the reef in Hōnaunau Bay produces just 0.5 kg (1.1 pounds) per square meter. To offset erosion from urchins, at least 26% of the reef surface must be covered by living corals – and even more coral cover is necessary for it to grow. Gregory Asner, an ecologist at Arizona State University and study author, said what was happening in this part of Hawaii was emblematic of the mounting pressures facing reefs throughout the region. 'For 27 years I have worked in Hōnaunau Bay and other bays like it across Hawaii, but Hōnaunau stood out early on as an iconic example of a reef threatened by a combination of pressures,' he said, citing warming ocean temperatures, pollution from tourism and heavy fishing. The implications of coral decline are far-reaching. Coral reefs are sometimes dubbed the 'rainforests of the sea' because they support so much ocean life. They also play a vital role protecting coastlines from storm surges and erosion. 'If the reef can't keep up with sea-level rise, it loses its ability to limit incoming wave energy,' said van Woesik. 'That increases erosion and flooding risk of coastal communities.' Kiho Kim, an environmental science professor at American University, who was not involved in the study, said the findings highlight the fragility of reef ecosystems under stress. 'Dramatic increases in any species indicate an unusual condition that has allowed them to proliferate,' Kim said. That imbalance can undermine diversity and reduce the reef's ability to provide essential ecosystem services including food security and carbon storage, he told CNN. Despite the challenges, researchers emphasize that the reef's future is not sealed. Local groups in Hōnaunau are working to reduce fishing pressure, improve water quality and support coral restoration. 'These reefs are essential to protecting the islands they surround,' van Woesik said. 'Without action taken now, we risk allowing these reefs to erode past the point of no return.'
Yahoo
21-06-2025
- Science
- Yahoo
An explosion of sea urchins threatens to push coral reefs in Hawaii ‘past the point of recovery'
The turquoise water of Hōnaunau Bay in Hawaii, an area popular with snorkelers and divers, is teeming with spiny creatures that threaten to push the coral reef 'past the point of recovery,' new research has found. Sea urchin numbers here are exploding as the fish species that typically keep their populations in check decline due to overfishing, according to the study, published last month in the journal PLOS ONE. It's yet another blow to a reef already suffering damage from pollution as well as climate change-driven ocean heat 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, first noticed unusually high numbers of sea urchins on snorkeling trips. 'I knew there was a story to be told,' she said. She and her fellow researchers used data from scuba surveys and images taken from the air to track the health of the reef. 'We found on average 51 urchins per square meter, which is among the highest recorded densities on coral reefs anywhere in the world,' van Woesik said. Sea urchins are small marine invertebrates, characterized by their spiny bodies and found in oceans around the world. They play a useful role in preventing algae overgrowth, which can choke off oxygen to coral. However, they also eat the reef and too many of them can cause damaging erosion. In Hōnaunau Bay, the coral is already struggling to reproduce and grow due to ocean heat and water pollution, leaving it even more vulnerable to the erosion inflicted by sea urchins. Its rate of growth has plummeted according to the study. Reef growth is typically measured by the amount of calcium carbonate — the substance which forms coral skeletons — it produces per square meter each year. The reef in Hōnaunau Bay is growing 30 times more slowly than it did four decades ago, according to the study. Production levels were around 15 kilograms (33 pounds) per square meter in parts of Hawaii, signaling a healthy reef, according to research in the 1980s. Today, the reef in Hōnaunau Bay produces just 0.5 kg (1.1 pounds) per square meter. To offset erosion from urchins, at least 26% of the reef surface must be covered by living corals – and even more coral cover is necessary for it to grow. Gregory Asner, an ecologist at Arizona State University and study author, said what was happening in this part of Hawaii was emblematic of the mounting pressures facing reefs throughout the region. 'For 27 years I have worked in Hōnaunau Bay and other bays like it across Hawaii, but Hōnaunau stood out early on as an iconic example of a reef threatened by a combination of pressures,' he said, citing warming ocean temperatures, pollution from tourism and heavy fishing. The implications of coral decline are far-reaching. Coral reefs are sometimes dubbed the 'rainforests of the sea' because they support so much ocean life. They also play a vital role protecting coastlines from storm surges and erosion. 'If the reef can't keep up with sea-level rise, it loses its ability to limit incoming wave energy,' said van Woesik. 'That increases erosion and flooding risk of coastal communities.' Kiho Kim, an environmental science professor at American University, who was not involved in the study, said the findings highlight the fragility of reef ecosystems under stress. 'Dramatic increases in any species indicate an unusual condition that has allowed them to proliferate,' Kim said. That imbalance can undermine diversity and reduce the reef's ability to provide essential ecosystem services including food security and carbon storage, he told CNN. Despite the challenges, researchers emphasize that the reef's future is not sealed. Local groups in Hōnaunau are working to reduce fishing pressure, improve water quality and support coral restoration. 'These reefs are essential to protecting the islands they surround,' van Woesik said. 'Without action taken now, we risk allowing these reefs to erode past the point of no return.'
CTV News
21-06-2025
- Science
- CTV News
An explosion of sea urchins threatens to push coral reefs in Hawaii ‘past the point of recovery'
Expanding numbers of sea urchins threaten the population of coral reefs in Hawaii, research says. (Pexels/Kindel Media) The turquoise water of Hōnaunau Bay in Hawaii, an area popular with snorkelers and divers, is teeming with spiny creatures that threaten to push the coral reef 'past the point of recovery,' new research has found. Sea urchin numbers here are exploding as the fish species that typically keep their populations in check decline due to overfishing, according to the study, published last month in the journal PLOS ONE. It's yet another blow to a reef already suffering damage from pollution as well as climate change-driven ocean heat 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, first noticed unusually high numbers of sea urchins on snorkeling trips. 'I knew there was a story to be told,' she said. She and her fellow researchers used data from scuba surveys and images taken from the air to track the health of the reef. 'We found on average 51 urchins per square metre, which is among the highest recorded densities on coral reefs anywhere in the world,' van Woesik said. Sea urchins are small marine invertebrates, characterized by their spiny bodies and found in oceans around the world. They play a useful role in preventing algae overgrowth, which can choke off oxygen to coral. However, they also eat the reef and too many of them can cause damaging erosion. In Hōnaunau Bay, the coral is already struggling to reproduce and grow due to ocean heat and water pollution, leaving it even more vulnerable to the erosion inflicted by sea urchins. Its rate of growth has plummeted according to the study. Reef growth is typically measured by the amount of calcium carbonate — the substance which forms coral skeletons — it produces per square metre each year. The reef in Hōnaunau Bay is growing 30 times more slowly than it did four decades ago, according to the study. Production levels were around 15 kilograms (33 pounds) per square in parts of Hawaii, signaling a healthy reef, according to research in the 1980s. Today, the reef in Hōnaunau Bay produces just 0.5 kilograms (1.1 pounds) per square metre. To offset erosion from urchins, at least 26 per cent of the reef surface must be covered by living corals – and even more coral cover is necessary for it to grow. Gregory Asner, an ecologist at Arizona State University and study author, said what was happening in this part of Hawaii was emblematic of the mounting pressures facing reefs throughout the region. 'For 27 years I have worked in Hōnaunau Bay and other bays like it across Hawaii, but Hōnaunau stood out early on as an iconic example of a reef threatened by a combination of pressures,' he said, citing warming ocean temperatures, pollution from tourism and heavy fishing. The implications of coral decline are far-reaching. Coral reefs are sometimes dubbed the 'rainforests of the sea' because they support so much ocean life. They also play a vital role protecting coastlines from storm surges and erosion. 'If the reef can't keep up with sea-level rise, it loses its ability to limit incoming wave energy,' said van Woesik. 'That increases erosion and flooding risk of coastal communities.' Kiho Kim, an environmental science professor at American University, who was not involved in the study, said the findings highlight the fragility of reef ecosystems under stress. 'Dramatic increases in any species indicate an unusual condition that has allowed them to proliferate,' Kim said. That imbalance can undermine diversity and reduce the reef's ability to provide essential ecosystem services including food security and carbon storage, he told CNN. Despite the challenges, researchers emphasize that the reef's future is not sealed. Local groups in Hōnaunau are working to reduce fishing pressure, improve water quality and support coral restoration. 'These reefs are essential to protecting the islands they surround,' van Woesik said. 'Without action taken now, we risk allowing these reefs to erode past the point of no return.' By Isabelle Rodney.
