“Unprecedented” ocean warming could make key habitats “inhospitable” for critically endangered angelsharks, according to new research.
The study, published in Global Change Biology, finds an “abnormal absence” of female sharks in a marine reserve near the Canary Islands throughout the 2022 breeding season.
This occurred during “unusually high” sea surface temperatures across the north-east Atlantic Ocean.
The study notes that the number of days with sea surface temperatures above 22.5C in the reserve nearly tripled over 2018-23.
This is significant, the authors say, because 22.5C is a “possible upper thermal threshold” for female angelsharks to tolerate.
The authors warn that ocean warming has “already altered” angelshark breeding behaviour, adding that the findings show that the species is “more acutely vulnerable” to climate change than previously thought.
Ocean warming
Angelsharks are flat-bodied, ray-like predators that can grow up to 2.4 metres in length.
They are typically found submerged in sandy habitats in the coastal waters of the north-east Atlantic Ocean and Mediterranean Sea.
They are listed as critically endangered on the International Union for Conservation of Nature’s (IUCN) red list of threatened species.
The authors note that the angelshark population has “declined substantially” due to “overexploitation” and “coastal habitat degradation”.
In the study, the researchers focus on the La Gaciosa Marine Reserve in the Canary Islands – Spain’s largest marine reserve.
The study notes that the Canary Islands are an “especially important region” for the angelshark and are at the “southernmost” boundary of the species’ distribution. As a result, angelshark populations around the islands have a “possibly lower tolerance for environmental change”, it states.
The researchers add that the north-east Atlantic Ocean is “undergoing rapid warming, characterised by exceptionally high temperatures and record-breaking marine heatwaves”.
As the climate continues to warm, extreme conditions are expected to occur more frequently and for longer, causing disruption to marine life.
The map below shows the historic and existing range of angelshark populations, as well as the locations of the acoustic receivers used to detect angelsharks in the study area.
To explore how climate change in the region is impacting the angelsharks, the researchers focus on “range shift”.
Range shift is when a species migrates to either remain in ideal conditions or avoid sub-optimal environments, according to what they can withstand as the climate changes.
It is one of the most “pervasive” consequences of ocean warming, the study authors say.
Tracking angelsharks
To track the movements of angelsharks, the researchers tagged the fins of 112 animals – 38 males and 74 females – over 2018-22.
These “acoustic tags” emit sound that enabled the researchers to remotely track angelshark locations.
The researchers then used this acoustic data to investigate seasonal and annual changes to angelshark presence at the study site, taking into account the contrast between male and female behaviours.
The researchers also modelled changes to the environment over 2021-23 using a range of variables. These included sea surface temperature (SST), salinity, surface wind speed and SST anomaly – a measure of how temperatures differ from the long-term average.
They also looked at concentrations of chlorophyll a and dissolved oxygen, as well as two variables that act as an indicator for levels of desert dust in the air.
The latter were used to incorporate into their model the effect of Calima events – hot and dusty winds that reach the Canary Islands from the Sahara Desert, which raise overall air temperatures.
This “environmental model” allowed the authors to investigate the relationship between angelshark presence within the reserve and changing environmental conditions.
‘Marked absence’
Previous research has linked seasonal angelshark behaviours – such as movement and presence in a certain habitat – to the breeding cycle and, sometimes, environmental factors.
The new study finds that angelshark presence in the study area varies seasonally for both sexes, peaking in November and December. It notes an additional peak in June for female angelsharks, which were also more “consistently present” in the study area throughout the year than males.
Author Dr David Jacoby is a lecturer in zoology at Lancaster University. He explains to Carbon Brief:
“Females will often avoid males outside of the breeding season as mating is pretty violent and energy expensive in sharks. Females consequently are more likely to occur in shallow water [since] males [are more likely to be found] in deeper water.”
The charts below show the relative influence of different environmental variables on predicting male and female shark presence in the study area.
The chart on the left shows how the day of the year has the biggest influence on male angelshark presence, followed by salinity. The chart on the right shows that for female angelsharks, SST – followed by SST anomaly – was the most significant predictor.
The “crux” of the study, according to Jacoby, is that in 2022 – when peak SSTs were higher and those conditions lasted longer – female angelshark numbers were “consistently low”. He tells Carbon Brief:
“The fact that there was this significant warming event in the north-east Atlantic was opportunistic from a research perspective at least, because it provided a natural experiment in which to directly compare behaviour under ‘normal’ versus ‘extreme’ conditions.”
This “marked absence” was especially noticeable during the angelshark breeding season in mid-to-late autumn, the data shows. In contrast, the behaviour of the male sharks did not change.
The charts below illustrate how, in 2022, daily counts of female angelsharks (orange bars in the middle panel) dropped in the unusually warm conditions, while daily counts of male angelsharks (turquoise bars in the bottom panel) remained consistent with previous years.
In the top panel, orange regions indicate periods in which SSTs are between 20.7C and 22.5C and red regions show periods of SSTs above 22.5C.
According to the authors, the presence of female sharks in the study site decreases “rapidly” at SSTs above 20.7C, while the “probability of female presence” is below zero above around 22.5C.
The dotted line at 19.6C shows the temperature of peak female angelshark presence.
The researchers say their findings “strongly” indicate that the low numbers of females during the breeding season in 2022 were linked to the “thermal extremes” that year.
They point to an “upward trend” in peak temperatures and longer duration of hotter periods in their dataset, noting that the number of days where SSTs reached 22.5C more than doubled over the study period.
As a result, the authors identify 22.5C as the “possible upper thermal threshold” for female angelsharks – meaning that the animals will not move into an area at this point.
They warn that regular temperatures of 22.5C could “disrupt” the timing of “key biological events”, such as breeding.
The “unusual” findings, recorded as “disrupted” thermal cues, may be a “window into future climate change impacts”, suggest the authors.
Conservation measures
The authors highlight the need to prioritise further “species-specific” studies that incorporate “real-time environmental and behavioural data” and explore climate impacts by sex.
Improving scientific understanding and prediction of how marine species and ecosystems respond to climate change are “urgent priorities”, they say.
Jacoby adds:
“Angelsharks [are among] the most threatened fishes in the world. Because they rely on the ocean floor to rest and hunt, they are extremely attuned to their local environment. [Ocean warming] could lead to the [local extinction] of this species from the archipelago in a very worst case due to the fact that they are already at their thermal extreme in this location…
“We still don’t really know how warming could impact the complex web of interactions within these coastal ecosystems. It is so hard to engage with a problem if you can’t see it for yourself.”
Dr Hollie Booth is a postdoctoral researcher in the department of biology at the University of Oxford and was not involved in the study. She tells Carbon Brief that although the negative impacts of climate change are “concerning”, overfishing remains “the greatest direct threat” to angelshark populations.
She adds:
“It is good to see empirical evidence of the impacts of climate change on threatened marine species. [The study] indicates how we need to make sure that contributors to climate change are also held accountable for mitigating [these] impacts.”
The post Endangered angelshark faces ‘inhospitable’ breeding sites as ocean warms appeared first on Carbon Brief.
Endangered angelshark faces ‘inhospitable’ breeding sites as ocean warms
As an extreme El Niño breaks marine temperature records, COP31 is set to boost the profile of the ocean’s role in solving climate change, but finance and clear conservation measures will be needed for it to move the needle, experts said.
The Turkish presidency has announced plans for an Antalya Ocean Declaration that recognises the centrality of the global ocean – the world’s largest carbon sink – in regulating the climate and minimising the now unavoidable overshoot of global temperatures above 1.5C over pre-industrial levels.
Meanwhile, as part of the formal UN negotiations, Australia has announced plans to land a cover decision in Antalya, which, according to veteran former US negotiator Sue Biniaz, would be the only section of the formal negotiations where the role of oceans could be included.
She added that an outcome at COP31 seems likely, given the initiative from both presidencies and a push from over 100 countries – including Brazil, the EU and the African Group of countries – calling for the UN negotiations to deliver a plan for implementing ocean measures.
Governments will arrive in Antalya with a “super El Niño” adding stress to marine ecosystems and expected to continue to intensify until December 2026, with parts of the Pacific averaging almost 30C (86F) – over 3C more than normal – in October, according to monthly EU sea temperature data.
-
COP31 Briefing: What to expect from the Antalya climate summit?
Electrification, the fossil fuel transition, adaptation to rising impacts, climate science and trade are key themes as governments gather for COP31 in Türkiye -
European nations signal support for fossil fuel roadmap, says COP30 president
André Corrêa do Lago told Climate Home News that it’s up to other nations to decide how the fossil fuel and deforestation roadmaps are used -
Nepal seeks stronger recognition of mountain issues in UN climate process
Flood-hit Nepal wants COP31 to adopt a new agenda item formalising work on mountains and climate change and boosting the response to rising risks
Needs for ocean conservation and funding
While elevating the ocean agenda is “critical”, it must lead to funding for ocean conservation and a clear plan for reaching the global target – set at UN biodiversity talks in 2022 – of protecting 30% of the global ocean by 2030, said Pradeep Singh, senior ocean governance expert at Oceano Azul Foundation.
The ocean is precisely where governments are farthest off track from meeting this target – informally known as the 30×30 goal. Even if countries meet all their nature conservation plans, only about 12% of the global ocean would be protected, the UN says.
“Acknowledgment of marine protected areas and the 30×30 target as climate infrastructures will certainly boost efforts and funding for science and management,” Singh told Climate Home News.
Shamini Selvaratnam, director of international climate and clean energy at Ocean Conservancy, said an ocean commitment that makes a difference in coastal communities “takes funding, local capacity and support that countries can actually access”.
An analysis by climate think tank Zero Carbon Analytics shows that investment in the blue economy – through activities like sustainable fisheries or cleaner shipping – is only at about 2% of the needs, which are estimated at $550 billion per year.
Following-through on commitments
Selvaratnam added that countries must also establish mechanisms to follow through on these measures, which currently only exists in the form of a non-binding dialogue that is not expected to produce any negotiated agreements.
She said that countries at COP31 must find ways for their ocean commitments to inform the next global stocktake, the UN’s five-yearly review of progress on climate action. Some countries – including African countries, Latin American nations, small island states and the European Union – have backed a process that culminates in the next global stocktake.
At climate negotiations, countries are not mandated to include ocean conservation measures in their climate plans. But a group of countries led by France and Brazil is pushing them to do so voluntarily through an initiative called Blue NDC Challenge. Seventeen countries have joined the initiative so far.
In its list of COP31 priorities, the EU has called for the “critical role” of oceans to be recognised, but falls short of calling for any specific actions to feature marine action more prominently in climate plans.
As part of their demands, ocean campaign groups have called for the establishment of an “Antalya Ocean Compact”, a platform where countries can coordinate efforts across different environmental treaties, including the UN climate, biodiversity and high seas negotiations.
Ultimately, Selvaratnam said a strong deal “must accelerate emissions cuts, clean energy, and a transition away from fossil fuels, including offshore oil and gas”.
Ilana Seid, chair of the AOSIS group of small island states and permanent representative of Palau to the UN, said during a press briefing last week that “meaningful progress” on emissions reduction is “the best way” to alleviate stress on the ocean.
The post ‘Blue COP31’ set to spotlight need for ocean protections amid record heat appeared first on Climate Home News.
‘Blue COP31’ set to spotlight need for ocean protections amid record heat
In the wake of its recent glacial flooding disaster, Nepal and the kingdom of Bhutan have proposed a new agenda item on mountains and climate change for the COP31 summit which opens on Monday in the Turkish city of Antalya.
In a submission addressed to the COP31 presidency and the head of the UN climate secretariat (UNFCCC), Nepal said the agenda item, entitled “1.5°C Warming in Mountains”, is an effort to strengthen the response of the international community to the climate risks facing the world’s mountain regions.
The item proposes that mountain issues should become a regular part of the formal UN climate change process, with a focus on scientific assessment of the risks associated with warming overshooting 1.5C, an annual high-level dialogue, a dedicated work programme and improved access to climate finance.
Maheshwar Dhakal, chief of the climate change management division of Nepal’s Ministry of Agriculture, Forests and Environment, told Climate Home News that Himalayan countries face similar problems such as collapsing glaciers and flooding from glacial lakes.
“We are trying to bring all Himalayan countries together under this agenda item,” he said.
COP31 Briefing: What to expect from the Antalya climate summit?
At this year’s UN General Assembly, Nepal’s Prime Minister Balendra Shah called for strong global action to ensure climate justice and proposed creating a Himalayan Climate Resilience Mechanism led by India, China and Nepal. It would share satellite data, monitor glacial slopes and lakes, strengthen early warning systems and coordinate cross-border disaster response.
Nepal has experienced significant infrastructure losses and human casualties from flooding every year since 2020. In late August, the collapse of a glacial slope on the border with Tibet caused a torrent of water and debris to course down the Bhote Koshi River, leaving more than 6,000 people dead or missing.
According to a government needs assessment, the disaster caused an estimated $2.7 billion in physical damage and economic losses, while around $4.8 billion will be required for recovery and reconstruction.
More research needed on threats
Although high mountain regions are known to be fragile ecosystems, especially as global warming accelerates glacier melt, the extent of their vulnerability is still not fully understood. When the devastating Bhote Koshi floods hit, it opened the eyes of the world to the risks.
Dhakal said the Bhote Koshi floods “have proved the impacts of climate change in the Himalayan region”, which were linked to rising temperatures by scientists with the World Weather Attribution group. “Therefore, Nepal wants scientific studies, research and political discussions on mountain climate risks to receive greater attention at international climate conferences,” he added.
Nepal has been making efforts on this front since 2009, when it held a cabinet meeting at Kalapatthar near Mount Everest. Since COP28 in Dubai, Nepal has organised high-level events and dialogues on mountain issues at COPs and is co-hosting one at COP31 with Bhutan, Pakistan, Kyrgyzstan and Tajikistan.
Editor’s Desk: Nepal’s disaster has laid bare the world’s adaptation accountability gap
Dhakal said the dialogues held so far have raised awareness, but mountain concerns must become part of the formal UN climate process to unlock climate finance and technical support that can bolster countries’ capacity to tackle climate threats.
If specific indicators and priorities are developed for mountain regions, vulnerable developing countries like Nepal would have better access to finance to help them adapt to the climate warming they have done very little to cause, he added.
More detailed data would enable them to prepare stronger project proposals for international climate funds, including the Green Climate Fund (GCF). In 2025, the GCF backed a project to protect livelihoods from climate-induced flooding in Nepal but it took seven years to get approval.
Sindhu Dhungana, an alternate board member at the GCF, said the problem is becoming more widespread and urgent for the Hindu Kush Himalaya region.
“The economies, cultures and almost everything in Himalayan countries depend on mountains,” he explained. “For us, climate change is mountain change… [it has] affected everything, including the economy and biodiversity.”
Destroyed development projects
Nepal wants the UN climate process to address mountain risks both before and after disasters. Countries need better research, technology, early warning systems and other adaptation measures to protect people and infrastructure. But even when countries take precautions, loss and damage is likely to occur and will require international support to address it.
Nepal has been provisionally allocated $21.6 million from the United Nations’ new Fund for Responding to Loss and Damage (FRLD) to help with the aftermath of the Bhote Koshi disaster, but this is just a fraction of needs and the money will come only months after it made an initial request.
Dhakal pointed to the damage caused by floods to infrastructure built with loans, such as the Melamchi Drinking Water Project, which received $312 million from the Asian Development Bank but was destroyed by a major flood in 2021, shortly after it began operating. The recent Bhote Koshi disaster wiped out a dozen hydropower facilities, as well as solar energy systems.
Nepal flood destruction shows “limits to adaptation”, scientists say
Nepal wants international discussions on what should happen when climate-related disasters destroy development projects built using credit, and how the loans should be treated afterwards.
“Climatic disasters wash out… projects, but the burden of loan is still paid by Nepal,” Dhakal said.
For now, it remains unclear whether the opening session of COP31 will consider or adopt the proposed agenda item on mountains and climate change, with consultations on how to respond still underway among governments and the COP31 co-presidencies.
“If countries agree to discuss the proposal and include it in the agenda, that would be another step forward,” Dhakal said. “Further discussions in the coming years could gradually give the mountain agenda a stronger shape.”
The post Nepal seeks stronger recognition of mountain issues in UN climate process appeared first on Climate Home News.
Nepal seeks stronger recognition of mountain issues in UN climate process
Some governments have backed using Brazil’s voluntary roadmaps on fossil fuels and deforestation to inform the next UN assessment of global climate action, a key process that concludes in 2028, the COP30 presidency told Climate Home News.
Brazil published the roadmaps on transitioning away from fossil fuels and on halting deforestation by 2030 this week, after failing to secure an agreement in Belém to make them part of formal negotiations. The documents set out a menu of policies countries could use to start acting on both issues straight away.
At their launch, Brazilian top climate officials argued the roadmaps could feed into the second stocktake negotiations. Through that process, due to start at this year’s COP, countries are meant to take stock of collective progress on climate action and decide on a plan to ramp up ambition in future policies.
In an interview with Climate Home News in London, COP30 president André Corrêa do Lago said that “some European governments” had signalled their support for the Brazil-led roadmaps to inform the global stocktake negotiations.
“I hope that there will be many other countries that may support this,” he said. “It’s not that you have to take the entire package, because who are we to come up with the solution? But some elements of the roadmaps may be useful.”