Conservation News: Giant Clams, Elephants, Predator Control

Giant Clams Being Poached, South China Sea Being Destroyed

A volunteer rearranging young clams at the Bolinao marine laboratory in an effort to restock the species in the region. Photo By: Adam Dean

Biologist Ed Gomez at the University of Philippines Marine Science Institute received a call 25 years ago from a broker whose client wished to buy young giant clams his team were culturing. However, the Bureau of Fisheries does not allow the export of giant claims, and despite applying for permits, Gomez and his team were denied.

He had hoped to be able to figure out how to breed the clams in captivity so that the Filipino fishermen could supplement their income by growing it themselves rather than poaching it.

A couple of weeks later, the institute’s clams started disappearing by the hundreds within several weeks. “They were stolen,” Gomez says.

At the time, the colorful species of giant clams were in demand for the aquarium trade. The lab was one of the two institutions raising the slow-growing clams whose soft tissues glow in hues from seafoam green to deep blue and bright purple. Most likely, Gomez states, his clams were ending up in people’s aquariums.

To prevent more from being stolen, the lab switched from raising the colorful species to the biggest of the twelve species of giant clams: the Tridacna gigas. As juveniles, they are plain-looking and unappealing to collectors. However, breeding the Tridacna gigas, categorized as ‘vulnerable’ by IUCN, would focus the team’s purpose of restocking this nearly extinct species in the Philippines and South China Sea.

Gigas clams can grow up to nearly four feet (1.2 meters) long and weigh 500 pounds (227 kilograms). As filter feeders cleaning up pollutants from algae and plankton, they play a significant part in keeping the South China Sea’s shallow water reefs alive and healthy. They also provide a home and protection for seaweeds, sea sponges, snails, slugs, and young fish.

The captive-bred giant clams pictured here are about five or six years old. Photo By: Adam Dean

However, since the late 1900s, demand for the giant clams skyrocketed. During the ‘70s, the Asia-Pacific region was picked clean for the giant clams’ meat, prized as a supposed aphrodisiac in China. The ‘80s came the aquarium trade. Now, giant clams are in demand for carvings, jewelry, and other ornaments. They have become a status symbol for the wealthy, who were looking for a less stigmatized symbol that would not cause legal issue, and as protective charms in Chinese Buddhism.

“[Giant clam poaching is] going to have an effect on the whole system, from coral reefs in general to pelagic fish that come swimming through and feed on reef fish,” explains John McManus, a marine biologist at the Rosenstiel School of Miami studying the South China Sea’s reefs.

Some of the most biodiverse reefs on Earth are located in the South China Sea. But more than 60 square miles (160 square kilometers) of reefs, almost 10%, have been destroyed during the ongoing territorial dispute in the South China Sea. Gomez estimates that the reef destruction will mean $5.7 billion a year in potential economic loss, particularly within the fishing industry.

In economic terms, coral reefs are the single most valuable ecosystem on Earth. According to a 2012 paper by ecologist Rudolf de Groot at Wageningen University and Research Center, a hectare (2.5 acres) of reef has a potential value of approximately $350,000 a year.

For millions living in the countries around South China Sea, fishing is their only livelihood. They are responsible for more than 10% of the world’s annual fish catch. But if the reefs disappear, so do the fishermen’s livelihood. With a market demand to absorb their supply, fishermen had the motivation to poach.

Gilbert Elefane, a Filipino fisherman from Quezon City, has seen the effects of poaching. As fishermen weigh and transport their catches from boat to shore, stacks of styrofoam boxes in wooden crates have yet to be filled with fresh fish.

The day before he had returned from a trip to the South China Sea, Elefane describes his experience watching poachers dive down and resurface with a rare giant clam. Their method was to use the boat’s propeller shaft as a pulley to lift the clams out of the sea, which destroy the reefs and ruins the ecosystem.

Poachers in the South China Sea use their boats’ propellers to break up the coral that encases giant clam shells. It leaves reefs broken and barren. Photo By: John McManus

Poachers face few consequences, and the degradation has garnered little attention on the international stage.

Gregory Poling, director of the Asian Maritime Transparency Initiative at the Center for Strategic International Studies, says “Most Chinese citizens have no idea what kind of environmental devastation China has done in the South China Sea.”

Times have been changing though. In early 2015, Beijing began to take a tougher stance against illegally harvested clams, according to Zhang, the research fellow in Singapore. “On one hand, they tried to prevent fishermen from going out to harvest clams in the South China Sea. On the other hand, they’re trying to take legal measures against people who purchase giant clams.”

Furthermore, China’s island building was halted as investigations revealed that Chinese officials were aware that their fishermen were poaching sea turtles, coral, and giant clams “on a substantial scale” and that island building has involved international environmental agreements.

Now, marine biologists and political scientists are watching to see how China will react to its loss at the international tribunal, hoping that the decision will eventually encourage China to cooperate.

Critical Reefs Destroyed in Poachers’ Quest for World’s Biggest Clams

Completion of the Great Elephant Census Reveals Devastating Results

After two years, the results of the Great Elephant Census (GEC), the largest ever continent-wide wildlife survey, has finally been released at the IUCN World Conservation Congress in Hawaii on August 31. Unlike previous assessments, the GEC is the most advanced and thorough assessment.

Prior to European colonization, scientists believed the African population may have been as many as 20 million. By 1979, only 1.3 million remained.

elephant count

Now the census reveals that it has gotten far worse: only 352,271 savanna elephants remained in only 93% of the species’ range. The current yearly loss is estimated at 8% or 27,000 elephants slaughtered. The rate of decline accelerated from 2007 to 2014. If nothing changes, according to the survey, elephant numbers could half to 160,000 in nine years with localized extinction a guarantee.

The aerial survey encompassed 463,000 km (9,700 hour total flights) covering 18 African countries. In 15 of those, where information on previous populations existed, 144,000 elephants were lost to ivory poaching and habitat destruction in less than a decade, a decline by 30% between 2007 and 2014.

84% of the population surveyed was sighted in legally protected area while 16% were in unprotected areas. However, high numbers of elephant carcasses were discovered in many protected areas, indicating that elephants are struggling both inside and outside of parks.

The three remaining countries with significant elephant populations were not included in the study. Namibia did not release figures to the GEC and surveys in South Sudan and Central African Republic were postponed due to armed conflict.

The census was funded by Microsoft founder Paul G. Allen, led by nonprofit Elephant Without Borders, which is based in Botswana. The survey involved a team of 90 scientists, six NGOs, and two advisory partners: the Kenya-based conservation organization Save the Elephants and the experts from African Elephant Specialist Group.

These results will be vital information later this month. Elephants will be high on the agenda at the triennial meeting in Johannesburg, South Africa, of the Conservation on international Trade in Endangered Species (CITES), the body that regulates international trade in certain threatened animal species. For the first time ever, there will be concrete information to determine the future conservation and management of elephants.

A survey plane spots a herd of elephants in Botswana            Photo By: CNN

Paula Kahumbu, a Kenyan elephant ecologist and CEO of WildlifeDirect, believes that by providing an independent and scientifically robust assessment of elephants, the census will carry huge weight at the CITES conference. “Proposals will be considered on the basis of scientific fact,” states Kahumbu. “It’s vital that we have accurate data to inform policy.”

Despite the overall decline in population, it varies greatly from country to country.

The countries with the greatest declines were Tanzania and Mozambique, with a combined loss of 73,000 to poaching in the past five years. In Selous Game Reserve in Tanzania and Mozambique’s Niassa Reserve, elephant populations have plummeted by more than 75% in the past ten years.

Angola too gave a shock. Once hoped to a refuge for elephants after decades of civil war, it has the one of the highest poaching rates on the continent with a 22% drop in elephant numbers since 2005. (Previously in Conversation News, the survey’s results for Angola were covered in Conservation News: Lions, Elephants, and Otters.)

The Babile Elephant Sanctuary in Ethiopia hasn’t lived up to its name. Chase and the team counted a single herd of 36, the last in the Horn of Africa, an area roughly the size of Mexico.

A herd of elephants drinks in Botswana’s Okavango region. Photo By: Beverly Joubert

In contrast, South Africa, Uganda, parts of Malawi and Kenya, and the W-Arli-Pendjari conservation complex, the only area in West Africa with significant numbers of savanna elephants, were found to have stable or slightly growing herds.

Botswana is the continent’s elephant stronghold, with 130,000 animals, concentrated along the Chobe and Savuti river systems in the north and in the wetland oasis of the Okavango Delta. Along with South Africa and Zimbabwe, it accounts for more than 60% of all elephants tallied in the GEC.

Zimbabwe has the second highest number (83,000), mostly along the Zambezi River and in Hwange National Park. Overall, its population has dropped 10% since 2005.

Zambia recorded 20,839 elephants, an 11%decline during the past decade. But a regional population in the southwestern corner of the country has been terribly affected by poaching: Only 48 elephants were spotted in Sioma Ngwezi National Park, down from 900 in 2004. At the current poaching rate, this local population also faces imminent extirpation.

Lead investigator Mike Chase from Elephants Without Borders argues that “the elephant poaching crisis has moved from East and central Africa and is now on our doorstep in southern Africa. You just need to look at southwest Zambia and southeast Angola, which have the worst rates of elephant poaching on the entire continent. And when elephants are removed from those systems, poachers will look to the stronghold of northern Botswana.”

For more than a century, the ivory trade has been the fire that fueled poaching. In 1989 CITES placed a global ban on ivory trading, significantly stemming poaching at first. But twice since then, in 1999 and 2008, some southern African countries were allowed to sell ivory from their stockpiles. These sales are believed to have boosted ivory demand in Asia, spurring poaching and ivory smuggling.

This year, Zimbabwe and Namibia have put forward proposals to CITES to begin a legal and regulated trade in ivory. In reaction, 26 African nations with elephant populations, supported by many other countries and NGOs, have submitted a proposal to halt any trade in elephants and their products.

elephant population trends

At least two-thirds of the continental savanna elephant figures reported in IUCN’s 2016 African Elephant Status Report comes from GEC results. This report will be published to CITES and will be used to shape major policy decisions about the future of elephants.

“This was an extraordinary collaboration across borders, cultures and jurisdictions. We completed a successful survey of massive scale, and what we learned is deeply disturbing,” said philanthropist and Vulcan founder Paul Allen. “Armed with this knowledge of dramatically declining elephant populations, we share a collective responsibility to take action and we must all work to ensure the preservation of this iconic species.”

Paul G. Allen’s Great Elephant Census Reveals Dramatic Population Decline in African Savanna Elephants

‘Our Living Dinosaurs’: There are Far Fewer African Elephants than We Thought, Study Shows

African Elephant Numbers Plummet 30 Percent, Landmark Survey Finds

Study Shows Mass Predator Killing is Not Successful

A new study published in the journal Frontiers in Ecology and the Environment suggests that there’s little evidence that lethal predator control does anything to help ranchers and protecting livestock.

Wildlife officials in Washington State recently green-lit a controversial plan to kill a pack of wolves fingered as the culprits behind a spate of attacks on cows. Their idea was that taking out the carnivores could help prevent more livestock losses.

The United States used this justification to kill thousands of animals (coyotes, wolves, bears, etc.) last year. Other nations, including Canada and Finland, have also authorized predator hunts for this reason.

Pelts from four gray wolves shot by United States federal officials in Montana hang over a truck. A new study weakens the theory that killing predators can help protect livestock. Photo By: Joel Sartore

Adrian Treves, conservation biologist from the University of Wisconsin-Madison and co-author of the paper, says, “We know anecdotes and perceptions don’t get us very far when we’re dealing with a problem like livestock predation. The science of predator control has been slow and not very advanced.”

To test the effectiveness of these efforts and inform future policy and research, Treves and his colleagues reviewed all of the scientific evidence available dedicated to predator control on North American and European farms.

The scientists found that most of the research doesn’t hold up scientifically. Out of 24 studies since 1978, only half met scientific standards for experimental evidence. The others were set aside due to design flaws or accidental biases in the research.

Only two were deemed top notch because they took into consideration the possible effects of environmental conditions like disease that could influence livestock deaths. But, neither study focused on the effectiveness of killing predators. Instead, it concluded that certain nonlethal predator control methods helped ward off future attacks.

Six of the remaining twelve demonstrated prevention of livestock predation, while four showed no effect. Seven studies tested lethal methods. Despite using shoddier science, Treves stated they were “reliable enough to draw a reference” from. Of these, 71% detected no preventive effects against livestock attacks or detected counter-productive effects of losing more livestock. Only two showed that killings prevented livestock loss.The rest concluded that nonlethal methods were more successful.

Wolves killed this Montana rancher’s calf. In 2010, predators killed 220,000 cattle and calves in the United States. Photo By: Matt Moyer

“The majority of lethal methods appeared to waste time and resources, and threaten predators and livestock needlessly,” argued Treves. “[They] tend to be more risky for livestock and therefore for livestock owners than nonlethal methods.”

For instance, a 2013 study concluded that hunting cougars only increased their attacks on livestock. The research showed that hunting older males tends to lead to more predation because those males keep out the youngsters, who tend to be more aggressive.

The team noted that nonlethal methods were generally more reliable and effective in preventing carnivore predation on livestock. They also suggested that further research into predator control by independent scientists would help provide the best available science to livestock owners and taxpayers, and reduce financial waste and animal suffering.

Treves hopes that the findings will prompt governments and hunters to stop killing “problem” predators until better science becomes available. He believes this will aid ranchers as well as the public, whose tax dollars fund the wildlife agencies making these decisions in dealing with predation. “People deserve to hear the options and understand the evidence, especially if our government claims to be science-based in our policies.”

In the United States, the government program Wildlife Services kill thousands of predators a year as part of its mission to solve human-wildlife conflicts.Despite growing criticism, the program has always argued their methods were legitimate.

“Wildlife Services’ policies and decisions are based on the best available science,” Pamela Boehland, a spokeswoman for the program, wrote in an email. “Not all wildlife damage problems can be resolved using nonlethal techniques alone. Even with the use of single or combined nonlethal methods, livestock losses to predators often continue.”

Under the U.S. government’s Wildlife Services program, more than a million predators, like this gray wolf in Idaho, have been killed since 2000. Photo By: Jim and Jamie Dutcher

But, the new study shows that there is not enough science to support this practice. “Any government action that destroys wildlife should be scrutinized to a higher level,” he says.

Senior wildlife biologist at Yellowstone National Park Doug Smith, who was uninvolved in the study, says that the data fills a gap into the research into the effectiveness of predator-control methods. However, he points out that a culture shift is needed among ranchers, who often jump to lethal predator control because they think it offers a quick and easy fix.

“People are instant gratification creatures,” he explains. “A lot of ranchers are very comfortable with that model.”

Scientific Review Critiques ‘Shot-in-the-Dark’ Predator Control

The Case for Mass Slaughter of Predators Just Got Weaker


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