Best of our wild blogs: 11 Oct 17

Berlayar Creek shores are alive!
wild shores of singapore

Zhenghua Forest – 16 September 2017
Bugs & Insects of Singapore

33rd Singapore Bird Race (2017) – Arbitrator’s Report
Singapore Bird Group

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Rain storm during Saturday’s NSL disruption ‘not unusually high’, weatherman says

KENNETH CHENG Today Online 10 Oct 17;

SINGAPORE — While heavy, the rain storm that fell over parts of Singapore on Saturday (Oct 7) — when train services across nearly a quarter of the North-South Line (NSL) were crippled — lasted a “relatively short” time and was not unusually high by historical standards, the weatherman said.

Responding to TODAY’s queries, the Meteorological Service Singapore (MSS) said Bishan received the second-highest rainfall of 42.2mm within a half-hour period that day. Queenstown received heavier rainfall during that period, with 45.6mm of rainfall.

However, in terms of daily total rainfall, Ang Mo Kio registered the highest rainfall of 74.9mm on Saturday.

“While the rain over some parts of the island on Saturday was heavy, it was of relatively short duration and the rainfall recorded was not unusually high if compared to the long-term highest rainfall records for October,” said a spokesperson for the MSS.

Around the same period last year, rainfall was even higher. On Oct 3 last year, for instance, 53.4mm of rain fell over Changi in a 30-minute period, said the MSS.

While the rain over some parts of the island on Saturday (7 Oct) was heavy, it was of relatively short duration and the rainfall recorded was not unusually high if compared to the long-term highest rainfall records for October. Source: Meteorological Service Singapore

On Sunday, the Land Transport Authority (LTA) disclosed that a malfunctioning system of pumps was behind the underground tunnel flooding that began on Saturday evening and stopped services completely along six stops on the 26-station NSL.

The malfunctioning water-pumping system allowed water to overflow from the stormwater sump pit, where rainwater accumulates, into the tunnel through the rail tracks where trains from Bishan zip underground towards Braddell.

As a safety precaution, SMRT was forced to de-activate the trackside power supply, halting services between Ang Mo Kio and Newton stations until Sunday afternoon. This thwarted the journeys of thousands of commuters in one of the worst rail disruptions since 2011.

Engineering experts who spoke to TODAY said they were surprised by the official explanation of the events behind the service disruption.

National University of Singapore transport researcher Lee Der-Horng said it was “unique” that not one pump but a system of pumps had failed to activate, sending water spilling into the tunnel.

“They should (have a back-up system), if they don’t have one. If they had one, then that’s even more unacceptable, which means the first (system) and the back-up system all failed,” added Prof Lee.

He called on the LTA and rail operator SMRT to reveal when the pumps were last activated, noting that the devices could not be infrequently used given how common rain storms were in Singapore.

TODAY has sent queries to the LTA and SMRT on whether a back-up to the water-pumping system was in place, and if its systems had set off warnings before the incident happened. Both the LTA and SMRT have yet to respond to the two questions, as well as others on the number of commuters affected.

The extensive flooding in the tunnel between Bishan and Braddell has also raised questions about the extent of damage to the tracks, related equipment as well as the trains.

Assistant Professor Andrew Ng, a railway signalling, control and communications lecturer with the Singapore Institute of Technology, said the electronic components of trackside equipment contain metal, which corrodes easily when brought into contact with water.

This will shorten the lifespan of those components, including trackside signalling equipment and the bogies of trains — the undercarriage to which a train’s wheels are attached — affecting functionality to a certain extent.

He said the authorities should do another thorough check to ensure the equipment are in “sound” condition. Any components that have been affected significantly would have to be replaced, and others closely monitored for such effects, he added.


Flooding in MRT tunnels: Not enough answers, assurance from the authorities
Today Online 10 Oct 17;

The breakdown of train services along the MRT’s North-South Line over the weekend is still a talking point online. Facebook users want the full picture on how the MRT tunnels could be flooded — with a few offering their own theories — while some urge the public to be more understanding towards the workers dealing with the aftermath. Others talk about their unpleasant experiences of being caught in the fray.

Thanks to all those working round the clock. Must be tiring for staff members from SMRT & SCDF (Singapore Civil Defence Force). They must have made weekend plans to be with their families and friends, but am sure that’s not important because they needed to get the trains running... There are crazy things happening around the world... typhoon, earthquake, floodings, shootings, terrorism etc... this is only a minor disruption whereby there are other alternatives for us to get from Point A to B. Everyone just need to chill and stop being so negative. Just adjust for now. EMMA KRISH

We see how you’re trying to gain sympathy by choosing to focus on the hard work of staff members and engineers in this... And no doubt, they have worked hard. But what about any sort of accountability and genuine admission of fault from the people at the top? STELLA JOSEPHINE

Very often, huge advertisement signboards could be seen at MRT stations showing how SMRT employees are working tirelessly at night to keep the system functioning. First, no one doubts the competence of those workers on the ground, and their efforts should be duly rewarded by the authorities and/or operators. And it is their job. However, those advertisements sometimes appear to be intended to gloss over the failings of the management and the Government. SIVAKUMARAN CHELLAPPA

The questions we must ask the LTA (Land Transport Authority) is: Didn’t it know that torrential rains often happen in our nation? After more than 30 years operating the rail system, didn’t it anticipate frequent torrential rains? Just like the Taiwanese, when they built their train network, they are mindful of the frequent and unpredictable earthquakes, or even Hong Kong, the frequent typhoons that happen there. Even when there were breakdowns in service due to all these natural incidents, they took a shorter time to resume train operations... LTA admitted the flood was caused by a pump malfunction. So there was no regular and conscientious maintenance of the system? Somebody is not doing their job properly and conscientiously. KWAN SIEW KONG

The current upgrading works at Kallang River between Bishan Road and Braddell nearby to increase its drainage capacity could have played a part in the flooding, as the canal water flow could have been temporarily diverted, and the water may have found its way through an alternative route into the MRT tunnel... just my thoughts. MEILIZA AGOES

Horrible. Live in Woodlands, study in the city. Been hit Saturday night, Sunday... Took me more than double the time to get home Satirday night on a nauseating bus ride to Woodlands. Poor aircon ventilation, constant braking by bus driver (sudden, not gradual, which causes the discomfort), and then having to take another bus back to Admiralty... The 30-year-old MRT system has functioned so well in the past years, and SMRT should be maintaining or even improving its reliability. I’m glad we have buses and trains in Singapore offering connectivity. I’m not glad that the backbone of the transport system can have a day-long breakdown due to rain. JIN ZHIYAN KIM

*Comments were first posted on TODAY’s Facebook page and are edited for language and clarity.


Maintenance shortfalls behind water pump failure that caused massive NSL disruption: Report
Today Online 12 Oct 17;

SINGAPORE — Inadequate maintenance is believed to be behind the malfunctioning water-pumping system blamed for last weekend’s North-South Line (NSL) train disruption, Chinese daily Lianhe Zaobao reported on Thursday (Oct 12).

“The pump was not operable during a critical period due to a lack of maintenance,” the report said, citing anonymous sources.

Zaobao added that SMRT staff overseeing equipment maintenance could be transferred out of their posts for failing in their duties.

The newspaper also reported that SMRT’s management was mulling over the staff transfers, although the company did not confirm the matter. The report gave no indication as to how many employees from the transport operator could be affected.

SMRT’s vice-president for corporate communications Patrick Nathan told TODAY that the company does not comment on staff matters, but it was strengthening its building and facilities team in light of the disruption.

TODAY’s queries to SMRT and the Land Transport Authority (LTA) on what caused the malfunction, and when the pumps were last serviced and how often they were maintained, have gone unanswered since the start of this week.

The LTA had earlier disclosed that a malfunctioning water-pumping system was behind the underground tunnel flooding that started on Saturday evening and halted services across six stops on the 26-station NSL.

The faulty system sent water overflowing from the stormwater sump pit, where rainwater accumulates, into the tunnel through the rail tracks where trains from Bishan travel underground towards Braddell.

SMRT was forced to de-activate the trackside power supply as a safety precaution, crippling services from Ang Mo Kio to Newton stations until Sunday afternoon. The disruption affected the journeys of thousands in one of the worst rail trip-ups since 2011.

A spokesperson for SBS Transit, which operates the Downtown Line, told TODAY that it had conducted extensive checks on its water-pumping systems and “have not found any issues”.

Earlier this week, TODAY reported that the downpour over parts of Singapore on Saturday, though heavy, was relatively short and not unusually high by historical standards.

The Meteorological Service Singapore said Bishan received the second-highest rainfall of 42.2mm within a half-hour period that day. During that period, heavier rainfall of 45.6mm beat down on Queenstown.

However, in terms of daily total rainfall, Ang Mo Kio had the highest rainfall on record of 74.9mm.

“While the rain over some parts of the island on Saturday was heavy, it was of relatively short duration and the rainfall recorded was not unusually high if compared to the long-term highest rainfall records for October,” the Meteorological Service Singapore spokesperson added.

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Bird Park to cover up show venue at new home to curb escapes

Audrey Tan Straits Times 11 Oct 17;

When the Bird Park moves to Mandai from its current Jurong premises by 2020, it will no longer have an open amphitheatre.

Instead, bird shows will be conducted in a mesh-covered amphitheatre, The Straits Times has learnt.

The mesh will prevent show birds from escaping into the sensitive habitats in the neighbouring Central Catchment Nature Reserve and disrupting the ecological balance there. It will also reduce the potential for conflict or aggression between show birds and native wild birds in the reserve over territory, for example.

The decision was made after consultations between developer Mandai Park Holdings (MPH), scientific experts and nature enthusiasts.

By 2023, visitors to the Mandai area will be able to visit the relocated Bird Park and new Rainforest Park, on top of the existing trio of attractions there: the Singapore Zoo, Night Safari and River Safari.

An earlier environmental report had indicated that all birds within the new Bird Park, including show birds in the amphitheatre, should be contained within meshed aviaries. A key concern was the risk of birds escaping.

However, as the current Jurong Bird Park has an open amphitheatre, MPH sought to recreate the visitor experience in Mandai by coming up with strategies to address the risk of show birds escaping. These include conducting shows under controlled settings, conditioning of the birds and adopting tracking technology.

But nature groups raised concerns on the potential for conflict between the show birds and native wild birds.

"The key concern was that this could have an adverse impact on the behaviour of the native birds," said Mr Philip Yim, senior vice-president at developer Mandai Park Development - MPH's development arm.

Given that there is no certainty these risks can be fully addressed, MPH decided to apply the precautionary principle, and decided on the mesh over the amphitheatre for the new Bird Park, said Mr Yim.

The precautionary principle is the strategy of taking preventive action in the face of uncertainty.

Park operator Wildlife Reserves Singapore (WRS) and tourism experts say visitor experience will not be impacted. While an open amphitheatre would allow show birds to fly in from farther away, a meshed amphitheatre presents new opportunities, said Dr Cheng Wen-Haur, WRS' deputy chief executive and chief life sciences officer.

"Leveraging the security provided by the mesh... we can fly a larger number of birds and of mixed species at the same time, and try out new species not used before for more stunning performances."

Show birds may also be left to fly around in the amphitheatre before and after a show, providing them the "freedom to express their natural behaviour".

Mrs Ong Si Qi, 27, who has two young boys, hopes the mesh is made of thin wires and built with a high ceiling.

"If the mesh isn't obvious to visitors, especially children, it should be okay. But if it is, it may be a challenge to explain to my two-year-old why the birds at the park are caged, while those he sees outside are free to move around," said Mrs Ong, a senior associate in operations management.

Ms Alicia Seah, director of public relations and communications at Dynasty Travel, said: "If the design of the amphitheatre is 'weather-proof', it means that it can be accessed during hot or wet days... which will be ideal too."

Dr Michael Chiam, Ngee Ann Polytechnic's senior tourism lecturer, said: "If it is designed in such a way that it blends in with the nature environment and the theatre, visitors may not even notice it."

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Malaysia: Johor Annual allocation a must to care for the environs - NGOs

zazali musa The Star 10 Oct 17;

JOHOR BARU: Environmental groups want the federal and state governments to continue allocating annual funding to them under Budget 2018 to carry out environmental-related activities and programmes.

Malaysian Nature Society Johor chairman Vincent Chow said continuous financial assistance was important to create better awareness on environmental issues among the people.

He said environmental-related NGOs could play a role as the ears and hands of the government.

“This would encourage more environmental-related activities and programmes by the state’s stakeholders,’’ Chow said.

“Different perspectives can counter the often slanted and biased reports on the environment by government departments,’’ he said.

Green Earth Society Johor president P. Sivakumar said the federal government budget was needed to address the water problems in Johor.

“It is a known fact that most rivers in Johor are either dirty or dead.

“The allocations should be used to rehabilitate and rejuvenate the rivers,’’ he said.

Sivakumar said more funds were also needed by the NGOs to educate the public and deter them from throwing rubbish into rivers, which were the main source of raw water supply.

“So far, there is no help in funding for the NGOs from the state government for our activities and programmes. We are not against development but Johor needs to have a balance between progress and sustainable environment for the people,’’ he said.

Sivakumar said the future generation should not pay a heavy price due to over development and lack of enforcement.

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Malaysia: Natural Resources and Environment Ministry launches RM855 million Environmental Quality Monitoring Programme

NOORSILA ABD MAJID New Straits Times 10 Oct 17;

PUTRAJAYA: The Natural Resources and Enviroment Ministry has launched a state-of-the-art Environmental Quality Monitoring Programme (EQMP) aimed at improving the existing environmental quality monitoring system.

Its Minister Datuk Seri Dr Wan Junaidi Tuanku Jaafar said the EQMP, which is implemented through a concession agreement with environment expert Scieno TW Sdn Bhd, encompasses real-time based data collection for the purpose of air, river and marine monitoring as well as the establishment of the National Environmental Command Centre (NECC).

"If the old system took 30 to 40 minutes to send data to the Department of Environment, this sophisticated new system only takes 10 minutes to send us real-time data," Wan Junaidi told reporters during the launch of the EQMP in his ministry today.

The NECC is located at the Department of Environment headquarters and will serve as a platform to analyse air, river and marine data obtained from environmental quality stations nationwide before being channeled to end users on a real-time basis.

"The NECC will do modelling, forecasting, geospatial mapping, mobile apps, web-based application and live video streaming," he said.

The EQMP will be implemented by Scieno TW for a period of 14 and half years involving a cost of RM855 million.

Manual, automatic and mobile facilities have been set up for incidents of pollution and air quality status across the country.

Hailed as the most expensive project for his ministry, Wan Junaidi said the concession agreement was also signed as part of measures to improve the existing programme with regard to the country’s development and current needs.

He said besides providing information on the current status of the country’s air, river and marine quality, the programme could also be used as an early-warning system.

“EQMP will also help in developing policies and assist in making decisions for the welfare of the people and the country through the provision of enforcement activities, inputs and planning of development projects,” he said.

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Malaysia: Call for collaborative efforts to preserve environmental health of Borneo

ADIB POVERA New Straits Times 10 Oct 17;

KUCHING: Environmental health in the whole of Borneo continued to record a declining trend last year.

This was highlighted in a joint report by WWF-Malaysia and its counterpart from Indonesia entitled “The Environmental Status of Borneo 2016” which was tabled during Experts Dialogue held in conjunction with the 10th Anniversary of the Heart of Borneo (HoB) initiative at Borneo Tarakan University, Tarakan, North Kalimantan, Indonesia, today.

In a joint statement released by WWF-Malaysia and WWF-Indonesia, it was stated that the joint report stressed that Borneo was at risk of “losing its major ecosystem”, which was critical to the long-term well-being of the local communities and the economies of the three HoB member countries namely Malaysia, Brunei and Indonesia.

WWF-Malaysia chief executive director Datuk Dr Dionysius Sharma introduces “The Environmental Status of Borneo 2016”, which is a joint report by WWF-Malaysia and WWF-Indonesia. Pix courtesy of WWF-Indonesia
WWF-Malaysia chief executive director Datuk Dr Dionysius Sharma reckoned that the HoB Initiative could play a bigger role as a leading example to create greater impact to the whole of Borneo.

“We need to ensure that all our efforts would also contribute to the overall environmental health of the entire island of Borneo,” he said.

The HoB initiative is a transboundary collaboration among the governments of the three nations, which was established in 2007 to conserve and sustainably manage the biodiversity, ecosystems and natural resources categorised as the Heart of Borneo.

Dionysius said the report showed that the initiative had fared far better compared to areas outside of the HoB boundary.

He said that although a large portion of Borneo’s lowland had been converted from forests to other land uses, much of the HoB area remained relatively intact.

“We are convinced that this is largely due to the success of the three countries’ visionary exercise to conserve the HoB that our governments have continuously committed since the joint declaration in 2007,” he said.

Meanwhile, WWF-Indonesia chief executive officer Rizal Malik said the findings on the environmental health report in Borneo would help stakeholders to plan for more sustainable future of the island.

“I am certain that this publication will be valuable reference for all development actors in Borneo and other partners to help maintain the sustainability of the natural capital of the island as one of the world's last remaining expanses of contiguous primary forest in the region,” he added

The dialogue was jointly organised by the HoB Indonesia National Working Group, Borneo Tarakan University and WWF.

Several other topics were also explored during the session including Biodiversity and Environment in HoB (Rhino and Elephant Conservation); Climate Change, Energy and Transboundary Watershed Management: and Challenges and Opportunities in HoB.

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Indonesia: Fire burns 12 hectares of Mount Rinjani area

Panca Nugraha The Jakarta Post 10 Oct 17;

Fire engulfed about 12 hectares of land in the Mount Rinjani National Park (TNGR) in Lombok, West Nusa Tenggara (NTB).

As of Monday night, some areas, particularly those on hilly terrain, were still on fire.

"The fire was first detected on Telaga hill, inside the TNGR area. It burnt about 12 hectares of forest and land in an area spanning about 1 kilometer," TNGR Agency Head Raden Agus Budi Santoso said on Monday.

The agency was quickly on the scene after it received reports about the fire on Telaga hill in Sembalun Lawang village, East Lombok, on Monday afternoon.

At least 27 firefighters were deployed to fight the blaze.

"We extinguished the fire near the village, but were unable to put it out in the steep areas," Agus said, adding that the terrain had hampered their efforts to prevent the fire from spreading.

Read also: Central, local govts not unified in protecting peatlands: Greenpeace

He said the fire was caused by local residents who were burning land. They were unable to control it and it quickly spread to the nearby forest. "We're still investigating who did the land burning in the first place." (foy/bbs)

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How has climate change affected Vietnam?

VietNamNet Bridge 10 Oct 17;

In 2016, the consequences of climate change in Vietnam were evident with 10 typhoons and seven tropical depressions in the East Sea (internationally known as the South China Sea), more than the average of many years ago. Of these, four storms and two tropical depressions directly affected the mainland.

In 2016, Vietnam also experienced 24 cold spells. During the cold spell in January 1, 2016, 40 sites were reported with snow – a phenomenon that had not occurred in hundreds of years in many places. The cold spell on January 21st recorded the lowest temperature for 40 years, causing widespread snowfall and frost in the northern mountainous region.

Typhoons, downpours, droughts, and saline intrusion were complex, contrary to all rules, difficult to forecast. In 2016, 22 large downpours across the country devastated many homes and fields.

Particularly, from October to December 2016, heavy rains caused severe floods in the central region. Five serious floods, seven flash floods and landslides were reported in the North. The flash floods and landslides caused by typhoons No. 2 and No. 3 caused serious damage in the northern mountainous provinces of Lao Cai and Yen Bai.

The 2016 also recorded 16 floods on the rivers in the Central Region and the Central Highlands. Serious, widespread floods were prolonged, causing severe flooding in Central Vietnam.

Material damage was also great, especially in the fields of agriculture, industry, infrastructure, health and the environment.

In 2016, the irregularities of the weather were increasingly severe, occurring throughout the country.

Specifically, in the dry season of 2016, many places in the South and the Central Region suffered from drought due to the drop in rainfall by 30-40% and the small water flow of rivers, leading to saline intrusion coming one month earlier in the estuary areas of rivers in the central region and especially in the Mekong Delta, where the salty water entered 80-100 km deep into the mainland. In these areas, farmers were disturbed by salinity, and lack of fresh water for daily life and production.

In the central region, the rainy season and the floods came late but they occurred repeatedly and lasted longer than usual during the last months of the year, causing huge damage to property and people. In the North, the first cold spell came early compared to previous years, but people did not feel the cold air of winter as the cold spells alternated with hot days.

In the dry season, the South as well as Ho Chi Minh City saw out-of-season downpours. The number of rainy days and the total rainfall in the dry season also exceeded the average of the same period of many years ago. Out-of-season rain caused damage to the winter-spring crop as well as fruit trees.

According to weather experts, there were many causes, particularly climate change, that changed some natural rules. Meteorological experts said the weather was in the neutral period and tended to move to El Nino (often associated with drought), so the rainy season in the South arrived earlier than it had many years ago.

It is undeniable that the weather in Vietnam in recent years has become increasingly abnormal. Droughts, floods, landslides, and storms have seriously affected the economy, which depends on agricultural production.

In particular, Vietnam is considered one of the countries heavily affected by climate change due to its long coastline. If the sea level rises by 1 meter, 40% of the area of the Mekong Delta and 10% of the Red River Delta will be inundated, which will directly affect 20-30 million people.

For Ho Chi Minh City alone, it is forecast to be one of the top 10 cities in the world most threatened by climate change. The strongest impact on the city is temperature, rainfall and tides. Flood in urban areas, sea water intrusion deep into the mainland, rising sea levels affecting production and clean water supply, infrastructure and people's life.

Climate change is the most serious challenge to sustainable development of all countries in the world, from developed to poor countries. Without effective response to climate change, socio-economic development will suffer, and sustainable development will face difficulty, or even fail.

To cope with climate change, since 2015 Vietnam has had 61 urgent projects with total budget of VND19,000 billion. Priority projects in the medium term were approved by the National Assembly and the Government, totaling about VND15,000 billion, focusing on the construction of a system of freshwater reservoirs; development and protection of protective forests, watershed forests, and mangroves; investment in environmental monitoring systems, and hydro-meteorological forecasting systems; and moving people out of dangerous areas.

In the long run, to develop a low-carbon green economy and reduce greenhouse gas emissions as Vietnam committed in the Paris Agreement, the country needs huge investment. Therefore, we need to quickly study and promulgate appropriate policies and measures to promote the participation of the private sector, in order to increase investment in reducing greenhouse gas emissions and adapt to climate change, then gradually transforming the economy that now depends largely on non-renewable fuels to renewable energy, improving energy efficiency.

In Ho Chi Minh City, many policies and measures to cope with climate change and integrated in many areas such as planning, energy, transportation, construction, waste management, water management, and agriculture have been issued. Specifically, Ho Chi Minh City has been involved in the C40 (the organization of leaders of cities in the world that are committed to climate change mitigation and adaptation) and has taken part in activities to reduce greenhouse gas emissions.

Ho Chi Minh City is currently working with the Ministry of Natural Resources and Environment of Vietnam and the Japan International Cooperation Agency (JICA) to study and design legal institutions, and create a legal corridor to, step by step, implement the Paris Agreement 2015.

The city has also cooperated with Osaka (Japan) in a program to develop low-carbon cities and with the city of Rotterdam (the Netherlands) in the program "HCM City develops towards the sea to adapt to climate change".

According to the latest information, Ho Chi Minh City will be built into the first smart city of Vietnam, becoming a place that gives special attention to protect the environment for all people.

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When anemones bleach, clownfish suffer

Phy.org 10 Oct 17;

Coral bleaching is a well-known consequence of climate change. What is less widely known is that sea anemones suffer the same fate, and this reduces the fertility of clownfish living in these anemones, as researchers from the CRIOBE, a laboratory jointly managed by the CNRS, the EPHE and Université de Perpignan Via Domitia, have just demonstrated in French Polynesia. Following a 14-month study, they are publishing their results in Nature Communications on Oct. 10, 2017.

Like corals, sea anemones live in symbiosis with microscopic algae, which gives them their color. Symbiotic clownfish protect themselves from predators by sheltering among the anemones' tentacles, and each month, lay eggs at their base. The anemones are also protected by the clownfish that they host.

Every other day, from October 2015 to December 2016, researchers and students visited 13 pairs of clownfish and their host anemones in the coral reefs of Moorea Island (French Polynesia). This monitoring was conducted before, during and after the 2016 El Niño event that triggered a warming of the Pacific Ocean (+2°C on Moorea Island compared to the 2007-2015 average—a combined effect of ongoing global warming and the El Niño episode) and a worldwide coral bleaching episode.

Half of the anemones monitored in this study bleached as they lost their microalgae. Among the clownfish living in the bleached anemones, the scientists observed a drastic reduction in the number of viable eggs (-73 percent). These fish were laying eggs less frequently and they were also laying fewer and less viable eggs, while these parameters remained unchanged among fish hosted by unbleached anemones.

Blood samples taken from 52 pairs of clownfish (including the 13 previously mentioned) showed a sharp increase in the level of stress hormone cortisol, and a significant drop in concentrations of sex hormones (the equivalents of testosterone and oestrogen).

The bleaching of the anemones due to increased sea surface temperatures is thus a stressor that reduces the levels of sex hormones and thus the fertility of the fish. These links have been found for the first time in the natural environment in which the fish live.

The health of the anemones and the fish improved between three and four months after the end of the warming event, long after temperatures had returned to normal. But would this have been the case had the warming episode been more intense, or longer? And faced with a new warming episode, will the clownfish that have already suffered this initial stress be better acclimatized, or more fragile?

To provide some answers to these questions, the team will monitor each individual during the next El Niño episode. Such monitoring is possible due to the fact that clownfish have a fairly long life expectancy and are sedentary, seldom moving from their host anemone.

The clownfish are not an isolated case. Twelve percent of the coastal fish in French Polynesia depend on anemones or corals to feed or to find protection from predators. In cases of prolonged bleaching, like that of the Australian Great Barrier Reef in 2016 and 2017, the renewal of all of these populations could be affected, and with them, the stability of the ecosystems.

More information: Ricardo Beldade et al, Cascading effects of thermally-induced anemone bleaching on associated anemonefish hormonal stress response and reproduction, Nature Communications (2017). DOI: 10.1038/s41467-017-00565-w


Read more at: https://phys.org/news/2017-10-anemones-clownfish.html#jCp

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