Mozzies pose unexpected challenges to Singapore’s Wolbachia project

SIAU MING EN Today Online 9 Dec 17;

SINGAPORE – A larger trial of Wolbachia-carrying Aedes aegypti mosquitoes will be delayed, after a recent field study at three sites threw up unexpected challenges in the form of mosquito movements.

Aedes aegypti mosquitoes from surrounding areas moved easily into the three sites – Braddell Heights, Tampines West and Nee Soon East – where their laboratory-modified male counterparts had been released. This hampered the latter’s ability to suppress the Aedes aegypti population at the release sites, said the National Environment Agency (NEA) on Friday (Dec 8).

A second challenge was the insufficient numbers of male Wolbachia-infected mosquitoes that reached higher floors of some housing blocks. This hampered suppression at high-rise blocks that had more Aedes aegypti mosquitoes at the higher floors.

Wolbachia is a naturally occurring bacterium found in more than 60 per cent of insect species, but not the Aedes aegypti mosquito – which spreads dreaded diseases like dengue and chikungunya.

When male Aedes aegypti mosquitoes that have been infected with Wolbachia are released and mate with females, the eggs do not hatch.

In addition to longstanding measures such as the destruction of breeding sites, this is a potential way to keep the mosquito population at a level where dengue transmission cannot be sustained.

The field study involving Braddell Heights, Tampines West and Nee Soon East began in October and November last year and lasted for about six months.

A larger suppression trial was to have started this year, but no date has now been set, after an expert panel advised the NEA to conduct further field studies.

A second field study will start in the second quarter of next year, with details on its scope and locations to be announced later, said the NEA.

Chairman of the Dengue Expert Advisory Panel, Professor Duane Gubler of Duke-NUS Medical School, said NEA would need to understand if there are potential barriers – such as roads, expressways and parks – that can stop the Aedes mosquitoes from entering the test sites.

“NEA’s Phase One field study has garnered valuable data, but it is important that further field studies be conducted to address the unique challenges that were surfaced during the study so that future application of this exciting technology can proceed more effectively,” he said.

The field study found that half the Aedes mosquito eggs collected from the release sites did not hatch. This means the Wolbachia-carrying male mosquitoes successfully mated with some Aedes aegypti females. But a larger reduction of hatched eggs and the adult population will be needed to suppress the Aedes population, said NEA.

The authorities also found that small releases of female Wolbachia-Aedes – which inadvertently slipped through during the sorting process - could see them taking over and becoming the dominant mosquito strain here. This would hamper the effort to use male Wolbachia-Aedes to suppress the population.

Improvements to existing sorting methods need to be explored, said NEA.

Careful and thorough studies have to be conducted over “several years” to ensure the technology is applied in the most effective way in Singapore’s unique urban landscape, NEA added.


Wolbachia-carrying mosquito study reports 50% suppression rate, phase 2 to start next year: NEA
Channel NewsAsia 8 Dec 17;

SINGAPORE: The first phase of a study on mosquitoes carrying the Wolbachia bacteria has been completed, with the successful suppression of 50 per cent of the targeted Aedes aegypti population, the National Environment Agency (NEA) said on Friday (Dec 8).

Since October 2016, male Wolbachia-carrying Aedes aegypti mosquitoes have been released on a regular basis at three selected sites at Braddell Heights, Nee Soon East and Tampines West. This is to understand their behaviour and ecology, and see if they can suppress the population of urban Aedes aegypti mosquitoes.

Since only female Aedes mosquitoes spread dengue by biting humans, if a male carrier of the Wolbachia bacterium mates with an uninfected female mosquito, the resulting eggs will not hatch.

NEA hopes that by releasing sufficient numbers of Wolbachia-carrying Aedes aegypti males, they can compete successfully against wild males and eventually drive down mosquito numbers as the population fails to reproduce.

Over time, this could also reduce the potential spread of dengue. NEA expects that the method could also help prevent the transmission of other mosquito-transmitted diseases such as Chikungunya and Zika.

Phase 1 of the study has met its objectives and a second recommended phase will commence in the second quarter of next year, NEA said.

The study reported that much fewer Aedes aegypti adult mosquitoes were found at sites where the male Wolbachia-Aedes mosquitoes were released, implying that the method is effective.

At the same time, half of the collected Aedes mosquito eggs did not hatch at the released sites, which provided strong indication that the released Wolbachia-Aedes males had successfully competed with the urban Aedes males and mated with some of the urban Aedes aegypti females.

HIGH-RISE URBAN LANDSCAPE POSES CHALLENGES

The field study also revealed two ecological challenges that are unique to Singapore’s high-density and high-rise urban landscape, and should be addressed to increase the impact of the suppression, the NEA said.

Firstly, the report noted how Aedes aegypti mosquitoes were able to move easily from surrounding areas into the release sites, thus reducing the suppression effect of Wolbachia-Aedes.

Secondly, it was noted that there is a high density of Aedes aegypti mosquitoes on higher floors, where not enough Wolbachia-Aedes mosquitoes can reach.

Data collected on how high and far the male Wolbachia-carrying Aedes aegypti (Wolbachia-Aedes) mosquitoes can fly, how long they live and their mating competitiveness in actual field conditions, will contribute to future field studies.

The Wolbachia technology, if proven effective, will further strengthen our capabilities to tackle dengue and other mosquito-borne diseases, the agency added.

"This is especially crucial as higher global temperatures resulting from climate change can have an impact on the spread of mosquito-borne diseases and public health," NEA said.
Source: CNA/kc

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Malaysia: Less than 350 tigers left in Malaysian jungle, WWF raises alarm

Kelly Koh New Straits Times 8 Dec 17;

MELAKA: World Wildlife Fund Malaysia (WWF-Malaysia) has raised concerns over the dwindling population of Malayan Tigers in the wild, saying that there is a need to protect the endangered big cat from extinction.

Its executive director Datuk Dr Dionysius S.K. Sharma said concerted effort from all parties were important in ensuring the survival of the species, which is also the national symbol of Malaysia.

"In the 1950's, there were an estimated 3,000 Malayan Tigers. In 1990, statistics by Perhilitan (Department of Wildlife and National Parks) showed there were 500 tigers left.

"Now, the latest figure is between 250 and 340 tigers," he told a press conference at the Sixth International Eco-Schools Conference attended by 71 students from Malaysia, Thailand and Singapore here today.

Present were Department of Environment deputy director-general (Development) Ismail Ithnin and WWF-Malaysia Markets and Education heads Thiaga Nadeson.

Dionysius made the stern call to members of the public to play their role in preserving the tiger, which has been classified as 'Critically Endangered'.

"Under the 11th National Plan, the government has allocated RM18 million to the Wildlife Department to conduct a survey to count tiger's population using chemo trackers.

"Although the data will only be released after a year or a year and a half later, we are concerned that the places where the tigers are spotted seems to be going down.

"This is one species that we cant afford to lose," he said.

"If we just sit down and do nothing, extinction will happen. All Malaysians, other than NGOs and the government must speak up so that all of us can work together to prevent the tigers from going extinct," he said.

Malayan tigers, scientifically known as 'Panthera tigris jacksoni', are found only in Peninsular Malaysia and in the southern tip of Thailand.

Dionysius also conveyed his concern over the extinction of leatherback sea turtles and the 'critically-endangered' Sumatran rhinos.

He said Sumatran rhinos, also the smallest of the living rhinoceroses were no longer found in Sarawak in the 1930's and the species is also no longer sighted anywhere in the Peninsular or Sabah.

"We are concerned as we have not been seeing these animals for the last few decades, although in real terms, we can only declare the animals as extinct if they are not sighted for 50 years.

"Currently, we only have two Sumatran rhinos in captivity," he said.

He added that the leatherback sea turtles, which are currently under the 'Vulnerable' status, were also no longer seen laying eggs at the Malaysian shores.

"We used to be one of the seven nesting places in the whole world where leatherback turtles will come to lay their eggs but over the last seven years or so, there has been no more leatherback turtles landing on our beaches to lay eggs.

"Although they still lay eggs in other parts of the world, but we do not have the nesting population in Malaysia anymore, and this is a concern," he said.

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Malaysia: Fish bombing endangers divers

OLIVIA MIWIL New Straits Times 8 Dec 17;

KUDAT: A number of divers were almost injured by fish bombing near Tanjung Simpang Mengayau here recently.

A seasoned diver, who wants to be known as Lee, said there had been several bombing incidences in Kudat waters while he was diving.

“Recently, while we were diving near Simpang Tanjung Mengayau, the fish bombing was so close to us that (the blast) seemed to cause the tank to explode.

“Not only my ears were painful but also my chest was feeling very uncomfortable,” he said, adding that his eardrums were likely damaged because of the incident.

He added that those engaged in fish bombing usually avoided people at sea. There are 10 dive sites in Kudat waters.

Tourism here has recently flourished with activities such as diving, surfing, paragliding and homestay for visitors.

The Sabah Tourism Board recently hosted the inaugural Music and Surf Fest here which saw hundreds of visitors from places such as Bali, Brunei and Finland.

District officer Sapdin Ibrahim said fish bombing had been plaguing Kudat for a long time.

“There have been many complaints of fish bombing, which not only endangers people’s lives, including the perpetrators, but also harms the marine ecosystem.

“Due to the huge marine park of 8,000 sq km, it is difficult to monitor and catch the culprits despite many joint operations by several agencies,” he said, adding that the fish bombers could lurk anywhere and anytime.

However, since last year’s gazettement of Tun Mustapha Marine Park, which covers Kudat, Pitas and Kota Marudu, the incidences of fish bombing have gone down.

He said besides conducting operations, there had been awareness programme on the dangers of fish blasting and their effects on the marine ecosystem.

The Sabah Fisheries Department echoed Sapdin’s statement on the improved situation in Kudat.

“In the 1990s, there were many cases brought to court but it is fewer now.

“For the past two years, there were three cases where we confiscated 285kg of fishes,” said Fisheries Department deputy director (Legal and Enforcement) Md Yusof Abdullah, adding that the offence fell under the Fisheries Act 1985.

Since last year, the department had conducted 70 operations both at sea and at the market in Kudat.

He added that the department faced several constraints in tackling fish bombing.

Besides having no base in Kudat, there was also a staff shortage with only three enforcement personnel.

“Our small boat cannot go far, thus limiting our area of operation.

“However, the department has been conducting joint operations with agencies such as the Malaysia Maritime Enforcement Agency and the marine police who have bigger assets.”

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Malaysia: Borneo pygmy elephant dies due to dehydration after being shot

The Star 8 Dec 17;

KOTA KINABALU: An endangered Borneo pgymy elephant has died from dehydration triggered by gunshot wounds.
Veterinarians and wildlife rangers could only watch helplessly as the gentle jumbo died due to injuries on his tongue and mouth.

"It could not eat or drink as we tried to provide treatment at the Borneo Wildlife Sanctuary," said Sabah Wildlife Department director Augustine Tuuga in a statement late Friday (Dec 8).

He said the seven-year-old bull elephant died on Dec 6, more than a week after it was rescued from the Desa Plantation near Telupid, some 210km from here.

He said villagers said the elephant was charging at people that were in its path.

"It was then captured on Nov 24 for relocation," he said.

Tuuga said the elephant was then taken to the Borneo Elephant Sanctuary for treatment.

While undergoing medical examination and treatment, its tongue was found to have serious wounds, believed to have been caused by gunshots.

"We are not sure whether this elephant was shot by poachers or villagers," Tuuga said.

A post-mortem found a bullet lodged in the elephant's front left leg, as well as other signs of gunshots on the body.

"However, the wounds on the body were only external," Tuuga said.

He urged villagers and estate owners as well as workers to inform wildlife rangers if they come across elephants on their land instead of handling the matter on their own.


Bornean pygmy elephant dies while undergoing treatment at Sabah sanctuary
AVILA GERALDINE New Straits Times 8 Dec 17;

KOTA KINABALU: A male Bornean Pygmy elephant died while undergoing treatment at the Borneo Wildlife Sanctuary in Kinabatangan, two days ago.

The elephant, aged between six and seven, was found dead in the morning by veterinary officers of the Sabah Wildlife Department.

Department director Augustine Tuuga, in a statement, said a post-mortem examination was conducted on the same day to establish the cause of death.

"During the examination, a bullet slug was found lodged in its injured front left leg.

"There were also sign of gunshots on the body but they did not penetrate or cause any internal organ injury.

A bullet slug was found lodged in the elephant’s front leg. Pic courtesy of Sabah Wildlife Department.
"The cause of death is believed to be due to dehydration as the elephant was unable to drink due to an injury on its tongue," he said.

The department's rescue unit had on Nov 24 captured the elephant, which is listed as a totally protected species, in Desa Plantation, Ladang Pertama for relocation and treatment.

It showed sign of injury on its left front leg and was aggressive towards estate workers and villagers.

Its appearance at Desa Plantation was first reported on Nov 5.

Tuuga said wildlife personnel were sent to manage the situation because the elephant was reportedly charging estate workers who came across its path.

The same elephant was also reported to have caused panic among nearby villages and estates in Telupid for its aggressive behaviour.

"After tracking the elephant for sometime, wildlife personnel finally encountered the elephant at Desa Plantation Nov 24 and successfully captured it.

"The elephant was then taken to the Borneo Elephant Sanctuary for treatment.

"While undergoing medical examination and treatment, its tongue was found to have a serious wound which was believed to have been caused by a gunshot.

"The wound on the tongue left the elephant unable to eat or drink," explained Tuuga.

While the department fully understood the problem faced by residents who encounter the elephant, Tuuga called on people to alert the authorities.

"We will investigate the case further as it involves the death of a totally-protected species," he said.

This is the second incident involving the death of Bornean pygmy elephants this week.

On Tuesday, a bull elephant was found dead with three gunshot wounds, within the Cenderamata Plantation Estate in Tawau. Its tusks were intact.

Last month, another male elephant with its tusks intact was also shot dead within the same plantation.

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Pacific's Palau forces tourists to sign eco-pledge

Channel NewsAsia 8 Dec 17;

KOROR, Palau: Visitors to the tiny Pacific nation of Palau are being made to sign a promise to respect the environment, in an innovative move that authorities hope will curb ecological damage caused by booming numbers of tourists.

Claimed to be a world first, the "Palau Pledge" is stamped onto visitors' passports and must be signed upon arrival in the country, which lies in the western Pacific about halfway between Australia and Japan.

"I take this pledge as your guest, to protect and preserve your beautiful island home," it reads in part.

"I vow to tread lightly, act kindly and explore mindfully."

With crystal clear waters, pristine reefs and abundant sea life, Palau is regarded as one of the world's best diving spots and was once a niche tourist destination.

But visitor numbers have exploded in recent years, particularly from China, straining both infrastructure and the environment.

The symbolic pledge was written with the help of Palau's children and President Tommy Remengesau said it was about preserving the environment for future generations.

"Conservation is at the heart of our culture," he said.

"We rely on our environment to survive and if our beautiful country is lost to environmental degradation, we will be the last generation to enjoy both its beauty and life-sustaining biodiversity."

Palau welcomed almost 150,000 tourists last year, up 70 percent on 2010 figures and the nation of 20,000 has struggled to cope.

Some of the new arrivals have caused outrage among locals by capturing turtles so they can take selfies with them, walking on fragile coral and leaving trash on beaches.

"The Palau Pledge aims to encourage environmentally sound habits in visitors," the government said in a statement.

"If action is not taken now, it will get to the point where it is too late to protect some of the most unique parts of the country."
Source: AFP

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Vietnam’s protected forest dwindling

VietNamNet Bridge 8 Dec 17;

Despite positive reports from authorities on the steady increase of the national forest cover, the size of the country’s protected forest is in fact decreasing at an alarming rate, experts said.

Pine trees in the protected forest in Ho Chi Minh Highway in Dak Song District, in the Central Highlands province of Dak Nong, are illegally chopped down. — VNA/VNS Photo

During a workshop on Thursday on the survival of protected forest, which plays a key role in mitigating the risks of landslide and flash flood in mountainous areas, Nguyen Hai Van of the Centre for People and Nature (PanNature) announced that Vietnam lost 1.7 million ha of protected forest from 2004 to 2014, 170,000 ha a year on average. The deforestation has left the country with only about 4.5 million ha of protected forest.

Such severe deforestation is often dismissed in the annual forest reports by the Administration of Forestry (AoF), as it focuses more on the total amount of forest cover. According to the AoF, Vietnam’s forest cover has risen remarkably over the last century, from 28 per cent of the country’s land area in 1942 to 41 per cent last year, and currently stands at 13.6 million ha. A surge of planted forest partly explains such encouraging numbers. But forest quantity does not necessarily indicate quality.

Natural forest, which has much higher biodiversity than planted forest and makes up a major part of the country’s protected forests, suffered the heaviest loss with 1.43 million ha disappearing nationwide. It alone accounted for 84.1 per cent of the total protected forest damaged, Van said.

“The deforestation occurred not just in certain areas but across wider regions, with hot spots in the northwest, Central Highlands and the south-central regions,” she said.

“The deforestation happened so fast that 59 management boards of protected forest had to reduce their forest statistics 118 times over the last ten years.”

The adjustments were made after protected forest areas were converted to production forests or were chopped down to make space for building new hydropower plants or mining minerals, Van said.

“The loss of natural forest partly explains why natural disasters of late have caused such devastating consequences,” she added.

Limited force

Mai Van Dam, deputy head of the Thach Thanh protection forest management board in Thanh Hoa Province, acknowledged the deforestation but said there was little the forest protection force could do to prevent it.

A management board usually must cover a very large forest area, ranging between 5,000 and 10,000 ha, but is assigned only 10 people to do the job.

Dam said that his board was forced to sign contracts with another 10 workers, but even that means one person must look after 250 to 500 ha by himself.

“The budget for the unit is also very limited, so that the monthly wage can only be at VND2.5-3 million (US$110-130), even though we must work very hard in the forests and mountains,” he said.

Nguyen Tuan Hung from the AoF’s Department of Special Use Forest and Protected Forest Management said that Vietnam planned to raise the amount of protected forest to 5.68 million ha by 2020, citing the country’s forestry development strategy. Vietnam must find a way to plant more than one million ha of protected forest in about two years to reach the set target, assuming no additional protected forest is lost.

“Without more aggressive measures to guard the forest, it is almost impossible to meet this goal,” Hung said.
VNS

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