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Scientists discover why sea urchins are dying off from US to the Caribbean.

A ciliate known as philaster is responsible for the sea urchin die-off. Photograph: Pascal Pochard-Casabianca/AFP/Getty Images. Theguardian.com

Marine biologists at a Florida university say they have solved the mystery of a mass die-off of long-spined sea urchins from the US to the Caribbean.

The scientists blame a microscopic, single-cell parasite for the die-off, which took hold early last year. Affected Diadema antillarum urchins lose their spines and suction, then succumb to disease.

The researchers, from Tampa’s University of South Florida (USF), also suspect the organism, a ciliate known as philaster, might have been responsible for wiping out about 98% of sea urchins in a similar episode in the region in the 1980s.

“I was like, ‘Yes, we have to figure this out,’ because in that 80s die-out, just the loss of this one species of urchin completely changed the fate of coral reefs,” Mya Breitbart, professor of biological oceanography at USF, told the Tampa Bay Times of the day she was invited to research the die-off in March last year.

Breitbart and a team including scientists from Cornell University and the US Geological Survey cracked the case within four months. Their study was published last week in the peer-reviewed journal Science Advances.

They identified the culprit by collecting samples from 23 sites around the Caribbean, including Aruba, the US Virgin Islands and Puerto Rico, and observing organisms attached to the sea urchins, which are known as the “lawnmowers” of coral reefs for their ability to consume decay-causing algae.

They were able to prove philaster was to blame by placing the organism in tanks with healthy, laboratory grown urchins and watching about 60% of the sample die with the same symptoms exhibited in the marine environment.

Breitbart said what surprised them most was the speed at which they were able to home in on the prime suspect.

“All of us on our team have been working on marine diseases for a long time, and this just doesn’t happen. This is really unprecedented to figure it out,” she said.

The cause of the 1980s die-off was not established at the time and may never be known, Breitbart said, because no samples from that outbreak still exist.

But the scientists did identify similarities between the two events, and say the outcome is the same: coral reefs clogged with algae and starved of nutrients, further adding to their precarious state.

Reefs in the Caribbean were already suffering from the fast-spreading and highly contagious stony coral tissue loss disease, scientists warning more than a decade ago that the entire reef system was in danger of collapse.

While there is no known method to eliminate philaster or protect sea urchins from it, Breitbart said, she is hopeful that further research will provide a breakthrough. Her team in Tampa has established a laboratory farm to study the organism, which is not harmful to humans.

“We’re excited to share this information with everyone, from reef managers to additional scientists so we can explore it further and try to stop its spread,” she said.

 

Mudança climática gera calor mortal na Índia e coloca desenvolvimento em risco

 

De acordo com novo estudo, o calor extremo representará uma ameaça à segurança energética e à saúde das pessoas e reverterá o progresso na desigualdade e na redução da pobreza 

 

Ondas de calor mortais alimentadas pela mudança climática estão ameaçando o desenvolvimento da Índia e correm o risco de reverter o progresso feito pelo país na redução da pobreza, saúde e crescimento econômico, descobriu um novo estudo.

As ondas de calor já afetaram criticamente o país, levando a quedas de energia, aumento da poeira e da poluição do ar e derretimento glacial acelerado no norte da Índia, disseram pesquisadores da Universidade de Cambridge no estudo publicado na revista PLOS Climate na quarta-feira (19).

Desde 1992, mais de 24 mil pessoas morreram por causa das ondas de calor na Índia, segundo o estudo. E os impactos devem se agravar à medida que se tornam mais frequentes, intensas e letais devido à crise climática.

 

“A Índia está atualmente enfrentando uma colisão de múltiplos riscos climáticos cumulativos”, disseram os pesquisadores. “As projeções de longo prazo indicam que as ondas de calor no país podem ultrapassar, até 2050, o limite de sobrevivência de um ser humano saudável descansando na sombra”.

O estudo mostra que milhões de pessoas a mais na Índia são vulneráveis às mudanças climáticas do que se pensava inicialmente. Mais de 90% do país pode ser severamente afetado por ondas de calor, caindo em uma zona de “perigo” de calor extremo, de acordo com o índice de calor, segundo o estudo.

O índice de calor mede a sensação térmica e considera a temperatura e a umidade do ar para avaliar o impacto do calor na população. No ano passado, a Índia experimentou uma onda escaldante, durante a qual partes do país atingiram mais de 49 graus Celsius.

Em 2022, a Índia experimentou seu abril mais quente em 122 anos e seu março mais quente já registrado, disse o estudo. E passou também pelo clima extremo em 242 dos 273 dias entre janeiro e outubro de 2022, descobriram os pesquisadores.

Esse estresse térmico repetido afetará milhões de vidas e meios de subsistência.

“Estimativas mostram uma redução de 15% na capacidade de trabalho ao ar livre durante o dia devido ao calor extremo até 2050”, constatou o estudo. “Espera-se que o aumento do calor custe à Índia 2,8% e 8,7% de seu Produto Interno Bruto (PIB) e reduza os padrões de vida até 2050 e 2100, respectivamente”.

 

Até meados do século, 70 cidades indianas devem ter mais de 1 milhão de habitantes, segundo o estudo.

O calor extremo representará uma ameaça à segurança energética e à saúde dessas pessoas e reverterá o progresso na desigualdade e na redução da pobreza, descobriram os pesquisadores.

“Minha família em Calcutá está sofrendo com as atuais ondas de calor que levam a frequentes reduções de carga”, disse o autor do estudo, Dr. Ramit Debnath, em referência a quedas de energia forçadas que reduzem a tensão na rede. “O nexo clima-energia está se tornando mais relevante”, acrescentou.

Normalmente, são os mais pobres e vulneráveis que mais sofrem. As ondas de calor “terão consequências sem precedentes na população de baixa renda”, disse o estudo.

Como exemplo, os autores apontam para a capital em rápida urbanização, Nova Deli, que “tem um alto nível de atividades de construção, principalmente envolvendo uma força de trabalho de baixa renda, que também corre sério risco de impactos de ondas de calor”.

Embora a Índia tenha um “índice de vulnerabilidade climática” por meio do qual avalia sua vulnerabilidade à crise climática, os autores acreditam que isso subestima o impacto das ondas de calor no desenvolvimento do país.

 

Sombra de prédio em Telangana, na Índia / Kaustav Sarkar / IPP Awards

A Índia se comprometeu com os Objetivos de Desenvolvimento Sustentável da ONU, uma lista de 17 objetivos que incluem reduzir a pobreza, a fome, a desigualdade e as doenças, além de promover saúde, educação e saneamento. Ao não entender a verdadeira ameaça das ondas de calor sobre sua população, a Índia corre o risco de perder esses objetivos.

A coautora do estudo, professora Ronita Bardhan, disse que as recomendações podem ser usadas para criar resiliência ao calor para moradias de baixa renda, pois “essas comunidades são mais vulneráveis aos impactos”.

“Pacotes focados no calor e na saúde para moradores de baixa renda e favelas são especialmente críticos, pois mostramos que as ondas de calor têm impactos devastadores na sustentabilidade urbana”, disse ela.

Outra aplicação prática são as estratégias de tornar a área urbana mais verde, principalmente em torno de áreas altamente densas, que “podem fornecer alívio dos efeitos das ilhas de calor urbanas”, disse Bardhan.

Os autores enfatizam a “urgência” ao recomendar que a Índia atualize sua avaliação de clima extremo para incluir o índice de calor e seu impacto no desenvolvimento sustentável do país.

“A Índia demonstrou uma tremenda liderança na ampliação dos planos de ação contra o calor nos últimos cinco anos, declarando as ondas de calor um desastre natural e mobilizando recursos de socorro apropriados”, disseram os autores.

Mas “à medida que as ondas de calor na Índia e no subcontinente indiano se tornam recorrentes e duradouras, é hora de especialistas em clima e formuladores de políticas reavaliarem as métricas para estimar a vulnerabilidade climática do país”.

What season is a hurricane?

 

The official hurricane season for the Atlantic basin is from June 1 to November 30, but tropical cyclone activity sometimes occurs before and after these dates, respectively. The peak of the Atlantic hurricane season is September 10, with most activity occurring between mid-August and mid-October.

Atlantic Hurricane Season

Swallowed by the sea

 

Read a full version of this story on Bloomberg.com.

When Nicola Bayless’s parents bought a house in Happisburgh, an idyllic coastal village in Norfolk, England, they were told it would be 150 years before erosion of the nearby cliff might threaten it. “They said, ‘We’ll be long dead and so will you,’” Bayless says. “But here we are.” 

That was 23 years ago. Today Bayless’s house is on the second-to-last plot on the road; its front windows look out on an empty lot that used to be a neighbor’s home until it was demolished in October. Just beyond that is the cliff, which Bayless says has retreated by eight meters in the past 18 months. The erosion has happened so quickly that Google’s Street View of the road, last taken in 2009, still shows it disappearing into the distance beyond her house. In 2023, though, there’s nothing but a “Road Closed” barrier followed by a sheer drop.

On England’s east coast, locals have been fighting a losing battle against the sea for generations. In Happisburgh, which faces ferocious weather from its perch on the North Sea, an estimated 250 meters of land was lost to erosion between 1600 and 1850. Locals have grown accustomed to storms, landslides and sometimes deadly floods. But over the past few decades, things have been changing faster than residents expected, and scientists are trying to understand how global warming might be making the destruction worse. 

Left: Google’s Street View of Beach Road, last taken in 2009. Right: Beach Road in January 2023. The wooden gate on the right of each picture is the same. Photographer: Olivia Rudgard

Losing the place you call home to an inexorable process is a unique kind of grief, but in Happisburgh that grief is compounded by centuries of history. Axes, flints and other tools as much as 950,000 years old have been discovered on its beach, including a set of footprints dating back 800,000 years, the oldest found in Europe.

Happisburgh also boasts a 14th century church, a beautiful stretch of bucket-and-spade coastline and a lighthouse built in 1790. The village’s local pub, The Hill House, dates back to at least 1540 and once hosted Sherlock Holmes author Arthur Conan Doyle (it inspired his story “The Adventure of the Dancing Men”). The constant thump of the sea against the cliff is audible from its rooms, where leaflets tell guests The Hill House will be “preserved for as long as the sea does not engulf Happisburgh.” 

“This is our house and our business,” says Clive Stockton, who has owned the pub with his wife Sue for the past 31 years. “When this goes we are destitute.” Stockton estimates The Hill House has about 20 years left.

Clive Stockton has owned The Hill House with his wife for the past 31 years.  Photographer: Nick Ballon for Bloomberg Green

The problem is the cliff. In Happisburgh, and along the rest of a 21-mile stretch of north Norfolk coast, it’s made up of sand, clay and silt — not solid enough to hold back the volatile North Sea, where heavier rain, higher tides and rising sea levels are predicted due to climate change. By 2100 local sea levels are expected to increase by at least a foot, and as much as three feet. Coastal erosion maps published by the North Norfolk District Council show a large swathe of the village threatened by 2055. By 2105 both the pub and church will be underwater.

In the early 2000s, the district council decided not to renew the sea defenses protecting the village. Today there is a rock “bund,” crowdfunded by the community in the 1990s, that protects the foot of the cliff and bought residents some time. But other engineered defenses would cost many millions. Ironically, the cliff’s archaeological value has also earned it a special designation, “site of special scientific interest,” which means the land has to be allowed to erode so that further discoveries can emerge. 

Many residents are angry at the decision. “We do seem to be the patsy,” says Stockton. “We seem to be stuck with a pre-ordained decision that Happisburgh cannot be defended.” 

Rising sea levels are expected to change tides and wave heights, which could accelerate things. Heavier rain in a warmer climate can also lead to more cliff collapse, though the overall impact of climate change is complex and site-specific, says Laurent Amoudry, principal scientist at the UK’s National Oceanography Centre. Usually, natural features like dunes would have the space to move landwards while maintaining their size, but in the UK, “where very little on the coast is actually natural anymore… you don’t have the space to roll back,” Amoudry says. 

Happisburgh Beach, where erosion is rapidly changing the coastline. Photographer: Nick Ballon for Bloomberg Green

Britain’s Committee on Climate Change, a government advisory body, has been blunt in its assessment that many coastal communities like Happisburgh are “unviable.” Last year, a report found that almost 200,000 properties around England may have to be abandoned because they are in places where defenses are too expensive or technically impossible. 

“There are these difficult decisions to make. Our current approach is not sustainable in the long term under intensifying climate change and rising sea levels,” says Richard Dawson, a member of the committee and professor of earth systems engineering at Newcastle University. “We have to start to plan out for these transitions now.”

See more photos from Happisburgh on Bloomberg.com