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Did toxic algae kill hundreds of elephants in Botswana?

Published

1 year ago

December 9, 2024

Did toxic algae kill hundreds of elephants in Botswana?

An investigation into the sudden deaths of at least 350 elephants in Botswana in 2020 has revealed the cause was almost certainly a “toxic brew” of open water tainted by a species of cyanobacteria that released cyanotoxins, essentially contaminating the elephants’ watering holes.

According to researchers, approximately 20 watering holes in Botswana’s Okavango Delta had been contaminated across roughly 6,000sq km (2,316 square miles).

So what happened, and how?

What is cyanobacteria and how does it harm elephants?

Although not all cyanobacteria, commonly referred to as blue-green algae, is toxic, some cyanobacteria can produce a type of deadly algal blooms (HABs) in standing water. This is the type which was discovered in the investigation carried out by researchers at King’s College London.

The study showed that the African elephants (Loxodonta africana) died in May and June 2020 after drinking from water holes contaminated with these toxic algal blooms.

“Scientists believe that the production of cyanotoxins is related to certain environmental triggers, for example, sudden rise in water temperature, nutrient loading, salinity,” Davide Lomeo, Earth observation scientist at King’s College London, a collaborator with Plymouth Marine Laboratory and the Natural History Museum in London, and lead researcher in the recent study, told Al Jazeera.

How did the elephant deaths come to light?

In early to mid-2020, a series of routine aerial surveys conducted by helicopter by the conservation organisation, Elephants Without Borders, revealed multiple elephant carcasses scattered across the landscape of the Ngamiland district of northern Botswana.

The aerial survey showed 161 elephant carcasses and 222 sets of bones, while also counting 2,682 live elephants throughout the eastern region of the Okavango Panhandle. In addition, the distance between the dead elephants indicated the deaths had been sudden, rather than gradual.

“The strong clustering of carcasses also suggests that the event was sudden, with limited dispersal of elephants prior to death,” the authors of the study said.

A combination photo shows dead elephants in Okavango Delta, 2020 [Handout via Reuters]

How did researchers identify toxic algae as the cause of death?

Before researchers confirmed it was toxic algae which killed the elephants, they had to rule out several other probable causes.

“Although this area is a known poaching hotspot in Botswana, this was ruled out since elephant carcasses were found with tusks intact,” the authors of the study said.

Other initial theories included virulent and bacterial causes, such as encephalomyocarditis virus or anthrax, but the evidence taken from the field – such as the age of the dead elephants and the absence of any clinical signs of disease, meant the researchers ruled these out as the cause.

The distribution of carcasses and bones suggested a unique “spatial pattern”, which indicated that localised factors may have played a role in the mass die-off. This led to further exploration of specific environmental and ecological conditions in the affected areas.

There were several other factors that served as evidence that the elephant watering holes were to blame. Using satellite photos, researchers measured the distance the elephants walked after they drank from the watering holes – an average of 16.5km (10.2 miles). Many of the elephants died shortly thereafter, roughly 3.6 days (88 hours), after they drank from the nearby contaminated water holes.

The report states that 88 hours aligned with previously reported toxicological timelines for other large mammals which have died from blue algal poisoning.

In addition, Lomeo’s previous body of doctoral work investigating the history of mass-mortality events and water quality in waterbodies in Africa served as evidence to further look into the theory of water hole contamination.

“This event was what led to this idea, since it was a well-covered news at the time, but no one really knew why they died. I then applied my skills in geospatial and computational data science to investigate the event under a well-known set of methods typically applied in epidemiological investigations (eg COVID-19),” explained Lomeo.

Blooming blue-green algae caused by cyanobacteria in water bodies, rivers and lakes can be poisonous for animals [Shutterstock]

What is still unknown about the elephant deaths?

It is impossible to measure the level of toxicity for each waterhole from aerial photos. In addition, it is unclear whether elephants drank from one watering hole or several, according to researchers.

“It is highly likely that they drank from multiple pans before their death. It cannot be established if the fatal intoxication occurred in a single drinking event, but it seems more plausible that if cyanotoxins were present and were the cause of the die-off, this was through toxins bioaccumulation in elephants’ organs,” stated the study.

Although it is clear that the toxic waterholes were the likely source of the elephants’ mass mortality, there remains some uncertainty about the findings due to the timing of the mass die-off.

“The event occurred during the COVID-19 movement restrictions, and timely intervention was not possible. Therefore, tissue samples [which would have confirmed the presence/ absence of cyanotoxins] were not collected. Post-mortem investigations also need to be done within a certain timeframe, beyond which samples would be too degraded. Additionally, cyanotoxins cannot be detected from satellites, so the links can only be but indirect,” Lomeo explained.

As the aerial data was collected considerable time after the deaths in March and May 2020 – researchers could not definitively rule out the involvement of other animals in the elephant deaths.

Furthermore, smaller creatures may have been missed in the aerial survey, potentially limiting scientists’ understanding of the full scope of the incident.

“The area is well-known for very high predation rates, meaning that animal carcasses disappear quickly because of scavengers like hyenas and vultures. Hence, the involvement of other animals cannot be ruled out,” Lomeo said.

The specific conditions that would produce the level of toxicity in a watering hole that would be lethal to surrounding animal species are also still unknown.

“There is still uncertainty. We know that certain cyanobacteria species are more likely to produce cyanotoxins, and we know which toxins each species typically produces,” said Lomeo.

According to the research, cyanotoxins exhibit significant variations in their potency and effects. Certain types are extremely toxic, capable of causing death even in very small concentrations. Others, while less immediately dangerous, may still pose health risks at higher levels without necessarily being lethal. The field of cyanotoxin research remains active, with many aspects yet to be fully understood and explored.

Despite this, the overall findings of the study have been widely accepted. “The cause of the die-off has been officially attributed by the Government of Botswana to environmental intoxication by cyanobacterial toxins, also known as cyanotoxins,” the study’s authors said.

Could this happen again?

Although mass deaths of elephants are rare, researchers cannot be certain it will not happen again and that it will only affect elephants or land animals.

“[In] all arid systems where animals are dependent on stagnant water in lakes/ponds are susceptible to this [mass die-offs], the aquatic life in lakes also can be harmed in this same manner. We have even seen this in rivers and oceans where high nitrification from agricultural run-off combined with warming temperatures leads to disastrous bacterial blooms,” George Wittemyer, a behavioural ecologist at Colorado State University, one of the institutes involved in a study in Kenya that revealed that elephants use individual names, told Al Jazeera.

While it was relatively easy for researchers to identify the elephant carcasses from the air due to their size, the sudden deaths of smaller animals might not be so easy to identify.

Related Topics:africa Botswana Climate climate crisis environment europe explainer Featured health news science and technology United Kingdom wildlife

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World

US, Mexico agree to begin talks on USMCA reforms, timing unclear

Published

37 minutes ago

January 29, 2026

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US, Mexico agree to begin talks on USMCA reforms, timing unclear

WASHINGTON, Jan 28 (Reuters) – U.S. Trade Representative Jamieson Greer and Mexican Secretary of Economy Marcelo Ebrard agreed on Wednesday to begin formal discussions on possible reforms to the United States-Mexico-Canada trade agreement, Greer’s office said.

Possible reforms for the USMCA Joint Review include stronger rules of origin for industrial goods, more collaboration on critical minerals, increasing efforts to defend workers and producers, and U.S.-Mexican efforts to combat “the relentless dumping of manufactured goods in our region,” the USTR’s office said in a statement.

USTR gave no details on timing for the talks and its statement did not say whether Canada would be involved. A USTR spokesperson did not immediately respond to a request for clarification.

Under the trilateral trade deal that took effect in 2020, the U.S., Mexico and Canada must launch a joint review of the trade pact by July 1, its sixth anniversary, to confirm their intention to renew it for a 16-year period or make modifications, in what USTR has described as a “sunset clause.”
Greer told lawmakers, opens new tab in December the USMCA’s “shortcomings are such that a rubberstamp of the agreement is not in the national interest” of the U.S. He has said the pact is not equipped to deal with surges of exports and investment from non-market economies such as China into the region.

U.S. President Donald Trump has been more blunt, saying this month that the trilateral trade pact was “irrelevant” for the U.S. despite a highly integrated North American economy.

After Wednesday’s meeting, Ebrard called the discussion positive in a social media video, and said the two sides talked about next steps for the USMCA and covered new U.S. tariffs, including those affecting Mexico’s auto exports to the U.S.

“This year it has to be reviewed, as you know,” Ebrard said of USMCA. “We have already moved forward on many issues so that the review goes as quickly and as well as possible.”

USMCA has shielded Mexico from the bulk of President Trump’s tariffs, as goods that comply with its rules of origin can enter the U.S. duty-free.

Mexico’s Economy Ministry on Wednesday reported that the country’s exports reached a record high of nearly $665 billion in 2025, growing 7.6% from the previous year, citing data from the national statistics institute. The United States accounted for 83% of the exports, followed by Canada at 3%, China at 2%, Germany at 1% and South Korea at 1%, according to the report.

THREATS TO CANADA

U.S. trade relations with Canada have worsened over the past week with President Trump last weekend threatening to slap 100% duties on Canadian goods if Ottawa proceeds with a limited trade deal with China that is expected to allow imports of up to 49,000 Chinese-made electric vehicles.

U.S.-Canada trade relations had already soured even before Canadian Prime Minister Mark Carney made a speech at the World Economic Forum that angered Trump.

Carney on Wednesday in comments to lawmakers denied that he has retreated from his speech in Davos, Switzerland, in which he urged nations to accept the end of the rules-based global order that Washington had once championed.

This drew criticism from U.S. Treasury Secretary Scott Bessent, who cautioned Carney against picking a fight with the U.S. as the USMCA review approaches.

Bessent said on CNBC television that Carney “rose to power on an anti-American, anti-Trump message, and that’s not a great place to be when you’re negotiating with an economy that is multiples larger than you are and your biggest trading partner.”

Reporting by David Lawder in Washington, Costas Pitas in Los Angeles and Brendan O’Boyle; Additional reporting by Iñigo Alexander in Mexico City; Writing by David Lawder and Ryan Patrick Jones; Editing by Tom Hogue

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World

UK reopens Chagos Islands talks with US following Trump criticism of deal: reports

Published

2 hours ago

January 29, 2026

Press Room

UK reopens Chagos Islands talks with US following Trump criticism of deal: reports

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Talks between the U.K. and the U.S. over the future of the Chagos Islands in the Indian Ocean have reportedly reopened after President Donald Trump’s comments cast doubt over an agreement that would see Britain hand sovereignty of the strategically vital archipelago to Mauritius.

British Prime Minister Keir Starmer confirmed Wednesday that the U.K. had reopened discussions after the president had panned the deal and branded it an “act of great stupidity,” GB News reported.

“Shockingly, our ‘brilliant’ NATO Ally, the United Kingdom, is currently planning to give away the Island of Diego Garcia, the site of a vital U.S. Military Base, to Mauritius, and to do so FOR NO REASON WHATSOEVER,” Trump had posted on Truth Social. “There is no doubt that China and Russia have noticed this act of total weakness.”

He added: “The UK giving away extremely important land is an act of GREAT STUPIDITY, and is another in a very long line of National Security reasons why Greenland has to be acquired.”

TRUMP WARNS US CAN NO LONGER THINK ‘PURELY OF PEACE’ AS HE PUSHES FOR GREENLAND CONTROL

Diego Garcia, the largest island in the Chagos archipelago and site of a major United States military base in the middle of the Indian Ocean, was leased from the UK in 1966. (Reuters)

The Chagos Islands were separated from Mauritius during Britain’s decolonization process, a move the International Court of Justice ruled unlawful in 2019.

The U.K. later agreed to transfer sovereignty while leasing Diego Garcia back for at least 99 years at a cost of at least $160 million annually.

Diego Garcia is a hub for long-range bombers, logistics and power projection across the Middle East, the Indo-Pacific and Africa.

Around 2,500 military and civilian personnel, mostly American, are stationed there. The base serves as a critical operation point for the U.S. and plays a central role in intelligence gathering and securing military communications.

Speaking aboard a flight to China, Starmer said he had “discussed Chagos with Donald Trump a number of times,” but declined to confirm whether the issue had been raised during a phone call between the two leaders on Sunday, The Financial Times reported.

TRUMP’S ‘SMALL ASK’ FOR GREENLAND WOULD BE THE REAL ESTATE DEAL OF A LIFETIME

British Prime Minister Keir Starmer says he “discussed Chagos with [President] Donald Trump a number of times.” (Leon Neal/Getty Images)

Starmer also said the matter “has been raised with the White House at the tail end of last week, over the weekend and into the early part of this week.”

Starmer also added that when the Trump administration took office, the U.K. paused the agreement for three months to allow the U.S. time to assess the deal at the agency level.

“Once they’d done that, they were very clear in the pronouncements about the fact that they supported the deal, and there were announcements made,” he said.

A Downing Street spokesperson also confirmed London was working to “allay any concerns” in Washington, according to GB News.

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“We will continue to engage with the U.S. on this important matter and the importance of the deal to secure U.S. and U.K. interests and allay any concerns, as we’ve done throughout the process,” the spokesperson said.

Trump’s comments on the Chagos deal had been welcomed by Reform UK leader Nigel Farage, who wrote on X: “Thank goodness Trump has vetoed the surrender of the Chagos islands.”

Fox News Digital has reached out to the White House and Downing Street for comment.

Emma Bussey is a breaking news writer for Fox News Digital. Before joining Fox, she worked at The Telegraph with the U.S. overnight team, across desks including foreign, politics, news, sport and culture.

World

Syria grants immediate citizenship to Kurds in wake of gains against SDF

Published

3 hours ago

January 29, 2026

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Syria grants immediate citizenship to Kurds in wake of gains against SDF

Interior Minister Anas Khattab’s order includes all listed as stateless and sets February 5 as deadline for its rollout.

Published On 29 Jan 2026

Syria’s Ministry of Interior has ordered the immediate implementation of a new decree granting citizenship to Kurdish minorities, as government forces continue to consolidate control of the country after a rapid offensive against the Kurdish-led Syrian Democratic Forces (SDF) in the north of the country.

Interior Minister Anas Khattab issued the decision on Wednesday, mandating that the decree applies to all Kurds residing in Syria and explicitly includes those listed as stateless, the Anadolu news agency reported, citing the Syrian television station Alikhbariah.