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Bleaching, It’s Not Just for Corals

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Bleaching occurs when a stressed marine creature, most commonly a coral, expels its symbiotic algae and turns a ghostly white, often in response to a warming sea. But bleaching affects more than just corals. Giant clams—massive mollusks that can grow more than 1.2 meters in diameter and weigh as much as 225 kilograms—can bleach, too. And in recent research, scientists have learned more about how bleaching disrupts these sessile giants, affecting everything from their nutrition to their reproduction.

Giant clams live on coral reefs and are the largest bivalves on Earth. Like corals, giant clams bleach when they’re stressed, often as a response to excessively warm water. As with a coral, a bleached giant clam expels the algae, called zooxanthellae, that live inside it. These algae dwell in the soft tissue of the clam’s mantle and provide energy for the animal through photosynthesis, leaving a bleached clam with less energy and nutrients. At worst, bleaching can kill giant clams through food deficiency.

Scientists have been studying bleaching in giant clams for decades. In 1997 and 1998, during a brief period that saw extensive coral bleaching worldwide with corals succumbing in at least 32 disparate countries, bleached giant clams were observed from Australia’s Great Barrier Reef to French Polynesia after water temperatures in the South Pacific rose significantly. In 2010, similar temperatures in the water off Thailand’s Ko Man Nai Island also led to scores of deaths.

Of the 12 species of giant clams, some are more resistant to heat stress than others. But as scientists are finding, even when a giant clam survives bleaching, other physiological functions can still be severely impaired.

A recent study in the Philippines of wild clams, for example, found that bleaching can hamper their reproduction. Bleaching reduces the number of eggs giant clams produce, and the more severe the bleaching, the fewer eggs they make. Reproducing “takes a lot of energy. So instead of using that energy for reproduction, they just use it for their survival,” says Sherry Lyn Sayco, the lead author of the study and a graduate student at the University of the Ryukyus in Japan.

Mei Lin Neo, a marine ecologist and giant clam expert at the National University of Singapore who was not involved in the study, says the work contributes to the story of how climate change can have “repercussions on the longevity of species.”

In general, she says, we know much more about how climate change affects corals than marine species with similar physiologies. “By understanding how other symbiotic species respond to climate change, each species becomes a unique indicator on how the overall reef ecosystem is doing.”

Bleached giant clams, it turns out, are often better than corals at coping with bleaching. Near Ko Man Nai Island, 40 percent of the bleached clams re-colored after a few months as the zooxanthellae repopulated in their tissues when temperatures cooled again. After the 1997–1998 bleaching event, over 95 percent of the 6,300 bleached clams near Australia’s Orpheus Island recovered.

Giant clams seem amenable to restocking, too. In the Philippines, where the largest species, Tridacna gigas, went locally extinct in the 1980s, restocking has brought it back.

“Clams are not just any organism,” Sayco says. “It’s not that we are just conserving them for them to be there,” she adds, “they have lots of benefits and ecosystem services, such as [boosting] fisheries [and] tourism.”

 

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The body of a Ugandan Olympic athlete who was set on fire by her partner is received by family

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NAIROBI, Kenya (AP) — The body of Ugandan Olympic athlete Rebecca Cheptegei — who died after being set on fire by her partner in Kenya — was received Friday by family and anti-femicide crusaders, ahead of her burial a day later.

Cheptegei’s family met with dozens of activists Friday who had marched to the Moi Teaching and Referral Hospital’s morgue in the western city of Eldoret while chanting anti-femicide slogans.

She is the fourth female athlete to have been killed by her partner in Kenya in yet another case of gender-based violence in recent years.

Viola Cheptoo, the founder of Tirop Angels – an organization that was formed in honor of athlete Agnes Tirop, who was stabbed to death in 2021, said stakeholders need to ensure this is the last death of an athlete due to gender-based violence.

“We are here to say that enough is enough, we are tired of burying our sisters due to GBV,” she said.

It was a somber mood at the morgue as athletes and family members viewed Cheptegei’s body which sustained 80% of burns after she was doused with gasoline by her partner Dickson Ndiema. Ndiema sustained 30% burns on his body and later succumbed.

Ndiema and Cheptegei were said to have quarreled over a piece of land that the athlete bought in Kenya, according to a report filed by the local chief.

Cheptegei competed in the women’s marathon at the Paris Olympics less than a month before the attack. She finished in 44th place.

Cheptegei’s father, Joseph, said that the body will make a brief stop at their home in the Endebess area before proceeding to Bukwo in eastern Uganda for a night vigil and burial on Saturday.

“We are in the final part of giving my daughter the last respect,” a visibly distraught Joseph said.

He told reporters last week that Ndiema was stalking and threatening Cheptegei and the family had informed police.

Kenya’s high rates of violence against women have prompted marches by ordinary citizens in towns and cities this year.

Four in 10 women or an estimated 41% of dating or married Kenyan women have experienced physical or sexual violence perpetrated by their current or most recent partner, according to the Kenya Demographic and Health Survey 2022.

The Canadian Press. All rights reserved.

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The ancient jar smashed by a 4-year-old is back on display at an Israeli museum after repair

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TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.

Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.

Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.

The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.

The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.

It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.

Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.

Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.

Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.

Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.

Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.

The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”

The Canadian Press. All rights reserved.

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B.C. sets up a panel on bear deaths, will review conservation officer training

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VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.

Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”

Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.

“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.

B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.

Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.

Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.

Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.

“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”

Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”

“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.

Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.

“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.

This report by The Canadian Press was first published Sept. 9, 2024.

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