Mass fish deaths: Lab test sheds further light on algal bloom

By Neo Chai Chin, TODAY, 4 Mar 2015

Laboratory tests of a seawater sample taken off Pasir Ris have zeroed in on the type of algae that wiped out massive quantities of farmed and wild fish in recent days.

The species of algae behind the mass fish deaths off Pasir Ris likely belongs to the Gymnodinium group. It is suspected to be Gymnodinium mikimotoi, according to the experts at DHI Water & Environment, but the exact species can only be confirmed through further genetic tests. Gymnodinium mikimotoi, also known as Karenia mikimotoi, is not toxic to humans, but has been associated with massive kills of wild and farmed fishes in Japan and Korea.

TODAY commissioned the laboratory test yesterday (March 3) using a water sample provided by a fish farmer operating off Pasir Ris. The sample was taken last Saturday when most affected fish farmers reported the sudden deaths of their stocks.

The test showed concentrations of the algae at 88,529 cells per millilitre – a “very, very high” concentration, according to Dr Hans Eikaas, head of environmental technology and chemistry at DHI, a not-for-profit group offering consultancy and water-modelling services.

Concentrations above 10,000 cells per millilitre are considered a full algal bloom by any international standard, he said. Seawater in normal conditions contain 200 to 300 cells per millilitre and comprise 100 or more different plankton species. Dr Eikaas said the algae bloom was the main cause of the fish deaths, with the algae likely clogging up the gills of the fish.

But ammonia in the seawater probably magnified the scale of fish deaths. Ammonia is a waste product of fish, and is also produced when bacteria decomposes organic matter without oxygen. More ammonia is produced when water is warm, and when there is more organic matter, such as when algae dies. In gas form, it is toxic to fish and can cause convulsions and death, said Dr Eikaas.

Water rich in ammonia and nitrogen is advantageous to algae in the Gymnodinium group. Warm water, which the Republic has seen in recent weeks, also stresses fish out. These factors mean “multiple blows” dealt to the marine life, Dr Eikaas said.

“I would assume ammonia building up could have caused sub-lethal toxicity to the fish – mainly, their gills get inflamed. Then algae doubles every 24 hours… (and the deaths) appear like a sudden event,” he explained. The algae would have taken about a week to bloom to the level shown in the lab test, he added.

If the suspected species is indeed the Gymnodinium mikimotoi, the algae is not known to cause any effect to humans who have eaten affected fish, Dr Eikaas said. Associate Professor Lim Po Teen of the University of Malaya’s Institute of Ocean and Earth Sciences said nutrient-rich coastal waters from human activities are believed to be the triggers of algal blooms. Another source of the problem is the introduction of algae species through ships’ ballast water. Efforts to mitigate harmful algal blooms so far include setting up perimeters at aquaculture farms and reduced feeding of farmed fishes, he said.

Dr Eikaas said the recent harmful algal bloom is a natural occurrence that is almost impossible to prevent, but with a monitoring system and simulation forecasting programme, it is not impossible to get a heads-up on. “With regular daily monitoring, we should have had several days’ lead time on this,” he said.

According to the Smithsonian National Museum of Natural History in the United States, Gymnodinium mikimotoi is associated with recurring blooms off the coasts of Japan and Korea and are associated with massive fish and shellfish kills. Blooms have also been reported in Australia, Denmark, Norway and Scotland.

Farmers contacted yesterday said they have spent recent days clearing dead fish from their farms. Some expressed hope that the Agri-food and Veterinary Authority would provide financial assistance, while others said they would relocate if given the chance. Fish farmer Simon Ho said his entire stock of over 30 tonnes of silver pomfret was wiped out. Marine Life Aquaculture chief operating officer Frank Tan said the company’s offshore operations lost 120 tonnes of four-finger threadfin and sea bass. The company had previously identified two sites – near the Southern Islands and Pulau Tekong – as possible areas to move to, but Mr Tan said that with different conditions such as bigger tidal waves, a move would entail a change of operations and re-investment.

Post by Ministry of National Development.

Govt to help fish farms, but farmers must be vigilant

AVA will help them build resilience through planning

By Carolyn Khew, The Straits Times, 6 Mar 2015

HELP will be given to fish farmers badly hit by a plankton bloom last week, but they must also do their part, said Minister of State for National Development Maliki Osman yesterday.

The assisting agency, the Agri-Food and Veterinary Authority (AVA), will provide assistance to fish farmers to recover and restart their operations.

It is also looking at how farmers can build resilience through contingency plans and carry out contingency exercises. But farmers, too, must be vigilant and proactive.

Yesterday, the Ministry of National Development said the AVA had alerted all the farms to elevated levels of plankton in the water, but not all of them took mitigating measures immediately, either because they did not have the tools to do so, or the means to afford them.

"Plankton bloom occurrences are very difficult to prevent, but it is possible to reduce the impact," said Dr Maliki after a visit to two farms located near the Lorong Halus jetty in Changi yesterday. "While we provide assistance to help farmers tide over this difficult period, it is also important for farmers to do their part to take mitigating measures early."

The AVA said the bloom killed an estimated 500 to 600 tonnes of fish as of Wednesday, and affected 55 out of 63 fish farms along the East Johor Strait. Its preliminary findings showed elevated levels of Karlodinium veneficum in seawater samples. "This plankton has been associated with fish kills worldwide," said an AVA spokesman.

Fish farmer Gary Chang said he was alerted to elevated plankton levels on Feb 16 and 17 by the AVA and started preparing for a bloom as early as Feb 20. The 58-year-old created a buffer by lining his net cages with canvas and installed a simple filtration system to maintain the air quality.

He said he lost less than $30,000 worth of fish this year, compared to $300,000 in a similar incident last year. "You have to prepare early. If you wait till the bloom hits, it will be too late," he said.

Dr Maliki, who visited Mr Chang's farm, said: "Other farmers also took measures, but unfortunately suffered severe losses as they may not have done so early enough."

This is the second bloom in as many years. Last year's incident killed about 500 tonnes of fish at 53 farms in both the East and West Johor straits, said the AVA spokesman. After that incident, farms had to restock their fish and some are planning to move to other sites.

Plankton blooms can be deadly as they suck oxygen from the water, suffocating other marine life.

The AVA said yesterday it was working with the Tropical Marine Science Institute at the National University of Singapore to conduct studies on plankton blooms.

An earlier tender called last year to design and develop closed containment aquaculture systems has also been awarded to five companies. The agency said no marine biotoxins were detected based on fish samples collected from the affected farms. It also said that live fish which are harvested from the farms are safe for consumption.

Post by Agri-Food & Veterinary Authority of Singapore (AVA).

Plankton bloom causing fish deaths 'likely to recur'
AVA and farmers must discuss best way to tackle challenge: Vivian
By Carolyn Khew, The Straits Times, 9 Mar 2015

THE plankton bloom behind the recent mass deaths of fish along the Johor Strait is likely to keep happening.

And this will pose a "real challenge for long-term fish farming in that area", said Minister for the Environment and Water Resources Vivian Balakrishnan yesterday.

"The Agri-Food and Veterinary Authority and the fish farmers are going to have to sit down to discuss what's the best way forward."

Two Saturdays ago, coastal farms in Changi lost thousands of fish to plankton bloom. Then last Friday, farms in Lim Chu Kang were hit. More than 500 tonnes of fish have been lost.

Asked about the issue yesterday, on the sidelines of the Green Corridor Run, Dr Balakrishnan said that plankton blooms tend to occur whenever there is a dry spell or drought.

This is especially true for the waters facing the Strait of Johor.

"This is likely to be a recurrent problem with global warming, with greater incidence of both droughts as well as heavy, intense storms," he added.

Plankton blooms can be deadly as the plankton suck oxygen from the water, suffocating other marine life.

The National Environment Agency said that the first half of this month is expected to have less rainfall than usual. This follows significantly low levels of rain in the previous two months.

The dry weather is partly due to the early onset of the north-east monsoon's dry phase, which is characterised by drier weather and occasional wind.

Last Saturday, dead fish, including catfish and mullet, were found washed up on the shores at Lim Chu Kang jetty, resulting in a clean-up operation by the National Environment Agency which continued until yesterday.

It is believed that more than 200 bags of dead fish were collected at the jetty.

Across the Causeway, Malaysian reports estimated that six tonnes of wild and cultured fish were found dead in areas such as Johor Port and Puteri Harbour.

The AVA said last week that it will provide assistance to fish farmers affected by the fish deaths, so that they can recover and restart their operations. There are 117 coastal farms around Singapore.

It is also looking to enhance their ability to better withstand such incidents - for instance, by putting in place contingency plans.

Fish farmer Simon Ho, who is in his 60s, hopes for a longer- term solution to prevent the mass fish deaths from happening again.

The plankton bloom wiped out all 80,000 of his silver pomfrets this year.

When the bloom hit last year, he managed to save half of his stock.

"I'm not going to start rearing fish again until there's a solution to the plankton problem," said Mr Ho, who owns New Ocean Fish Farm.

"We've tried so hard already."

Growing concern over future of fish farms
Recurring and more severe plankton blooms a big challenge for farmers
By Carolyn Khew, The Straits Times, 9 Mar 2015

THE plankton bloom which wiped out more than 500 tonnes of fish along the East Johor Strait last week, and seems to have now affected farms in the western side, has raised concerns on the industry's future here.

Affected farmers told The Straits Times that despite earlier warnings given by the Agri-Food and Veterinary Authority (AVA), they were shocked at how sudden and severe the latest bloom was.

Mr Simon Ho, who is in his 60s and has been in the business for five years, had put in oxygen compressors since receiving the warnings in the middle of last month. But he still lost all 35 tonnes of his fish- the product of more than a year's worth of work - at his farm off Lorong Halus jetty.

In January and February last year, thousands of fish died after being poisoned by plankton blooms caused by high temperatures and low tides.

But Mr Frank Tan, 40, who owns Marine Life Aquaculture, said that unlike last year, the bloom was much harder to detect this time.

The bloom typically turns water brownish-red, when the plankton appear in large numbers. This year, he did not see this happening.

Some fish farmers say their enterprise is a "high risk" one, given that they already have to cope with unpredictable environmental factors, such as temperature.

Of Singapore's 126 fish farms, 117 are coastal, and most grow their fish in net cages in the sea. That means the livestock is vulnerable to changes in the environment.

Now the worry is that the deadly plankton blooms may become an annual affair.

The answer may be to rear the fish in a closed containment aquaculture system, which will shield the animals from external factors.

These systems include putting the fish in giant tanks into which filtered and oxygenated seawater is pumped. These tanks can be placed on land or on platforms out at sea.

But older farmers are reluctant to make the change from the farming methods they grew up with and know so well, while others say containment systems simply cost too much.

Mr Ong Kim Pit, who is 65 and has been in the business for about 20 years, said: "It's not that easy. The containers can only rear so much fish and you need to spend thousands building them."

Still, there are those willing to take the plunge, with the help of the Government, which is encouraging greater local fish production to boost the country's food security. In 2013, 8 per cent of fish supply here came from local sources, and the plan is to increase this to 15 per cent.

Last August, the Ministry of National Development rolled out a $63 million Agriculture Productivity Fund to help local farmers boost their yields and raise productivity.

The AVA also this month awarded a tender to develop closed fish rearing systems to five companies.

One of them is The Fish Farmer, which produces 800 tonnes of fish annually at its Lim Chu Kang and Changi farms.

Chief executive Malcolm Ong, 51, hopes to grow his fish fry, which are more vulnerable to disease and the bloom, in tanks in about six months' time.

The system is estimated to cost $364,000, and AVA will reimburse some of the cost, he said.

Once the fish grow big enough, he will transfer them to net cages.

"I am really committed to finding a solution," said Mr Ong. "I am not going to be defeated by the plankton bloom."

Investing in new system to do better
By Isaac Neo, The Straits Times, 9 Mar 2015

THE recent plankton bloom wiped out Gills 'n' Claws Aquaculture's stock of fishes at its farm north of Pulau Ubin, causing losses of 27 tonnes of sea bass, red snapper and pomfrets, and leaving only lobsters.

But 45-year-old owner Steven Suresh is far from giving up.

He has invested more than $1 million in a closed containment system which he hopes will not just make it cheaper to rear fish, but also prevent future blooms from affecting livestock.

The new system, developed by the firm's 46-year-old aquaculture expert G. Prabhagar, works by pumping seawater into containers floating on the sea, after passing through a UV filter which kills plankton and bacteria. This way, the fish in the containers will be unaffected by plankton bloom.

Fish waste is also pumped out of the containers into the sea below, to feed the lobsters in nets.

The floating platform is largely made of galvanised metal, supported by polyethylene floats filled with compressed styrofoam, which makes it very sturdy.

It cost over $1 million to build, but Mr Suresh believes it is necessary to maintain the weight of the containers, which can contain up to 10 tonnes of water.

Mr Suresh, who started fish farming after he got a diploma in aquaculture from the University of Edinburgh in 2009, also owns farms in Sri Lanka and Malaysia.

The container system has been tested on its offshore farm in Malaysia, but this is the first time it will be done in the sea.

The original plan had been to roll it out at the end of the year, but this has been bumped to May, due to the mass fish deaths.

Each container will cost $50,000 to set up, and Mr Suresh hopes to have six containers at his Ubin kelong in two months' time.

Although it is pricey, he believes it will reduce the cost of feeding the fish by a fifth and cut mortality rates, saving money in the long run.

He intends to share the technology with other farmers, saying: "At the end of the day, we are all working together to produce food for Singapore."

Pinning hopes on relocation
By Carolyn Khew, The Straits Times, 9 Mar 2015

WHEN 40-year-old Frank Tan first saw signs, in the middle of last month, that a plankton bloom was coming, he tried to save his adult fish by moving them to inland tanks on Pulau Ketam, just opposite his Changi farm.

"I wanted to get three boats to tow our floating net cages, but that didn't work out," said Mr Tan. "The tides and wind were too strong."

The owner of Marine Life Aquaculture ended up losing 120 tonnes of fish in total - the bulk of his stock. He put the loss at $1.2 million.

Now, he is planning to make a permanent move.

In two months, he will move his net cages to either Pulau Tekong or the Southern Islands. The tides are stronger there, which makes it harder for plankton to grow in one place.

The entire process will cost him $500,000.

He set up the company in 2009 after quitting his job as a regional sales manager at an oil and gas firm.

His love for fish runs "in the blood", he said with a smile.

"My grandfather used to run a kelong, my wife came from a family of fishmongers and, these days, whenever my 21/2-year-old daughter goes to a fish shop, she points to the tanks and refuses to leave," he added.

His Pulau Ketam site already houses more than 80 tanks. Seabass and threadfin are kept there until they are about 100 days old, after which they are transferred to net cages.

They are then reared in the open sea until they reach a marketable size - 1.5kg to 2kg.

Mr Tan hopes to build more closed-containment systems eventually, but he said "skill" is needed to make them cost-effective.

For now, he is pinning his hopes on the relocation.

"It's too bad, but we should have moved there earlier," he said.

Closed-tanks pricier, but have proved their worth
By Carolyn Khew, The Straits Times, 9 Mar 2015

WHEN they started their farm near Pulau Ubin three years ago, Dr Michael Voigtmann and Dr Dirk Eichelberger knew that rearing fish in closed-containment systems was the way to go.

The Germans have pumped in $500,000 to invest in 40 such tanks and will be spending another $1 million to scale up their systems by end-June.

"We believe that net farming is simply too risky," said Dr Eichelberger, 51. "Besides the plankton bloom, you have other (aquatic) diseases. The water here is simply difficult to deal with."

Dr Voigtmann, 47, a Singapore permanent resident, said that apart from plankton blooms, fish also suffer from viral and bacterial diseases which may cause mortality. "You can vaccinate the fish, but it can't be protected from everything," he said. "Once we filter and treat the water with UV light, you can keep out almost all of the pathogens."

Their company - Singapore Aquaculture Technologies, was one of five awarded a tender by the Agri-Food and Veterinary Authority to design and develop closed-containment aquaculture systems.

Their system involves pumping seawater from a depth of 2m before filtering and passing it through UV light rays to kill almost all organisms, including plankton and bacteria.

For the record, the latest wave of plankton bloom on Feb 28 killed one-third of their fish stock, said Dr Eichelberger. But these were from tanks which did not have the UV systems.

"The good news for us, despite the disaster for so many farmers, is that the completed systems did their job and protected the fish."

* Help for fish farmers hit by plankton bloom
But they must show AVA they have plans in place to cope with future incidents
By Carolyn Khew, The Straits Times, 7 May 2015

FISH farmers who had their stock wiped out in the plankton bloom in February and March will receive government help to get back on their feet. But the aid comes with a condition - the farmers need to show that they are able to cope with future plankton blooms.

The plankton bloom affected 75 fish farms in the East and West Johor Strait, resulting in mass fish deaths. About 500 to 600 tonnes of fish died.

The Agri-Food and Veterinary Authority (AVA) said it will cover 70 per cent of the farmers' cost of restocking fish fry. But the farmers have to develop operationally ready contingency plans to show that they are prepared for recurring blooms.

Last year, the AVA co-funded 70 per cent of the cost to buy fish fry and co-funded the same amount for cost of new equipment. This time, AVA said farmers can tap the Agriculture Productivity Fund to purchase the equipment for contingency plans. They may receive co-funding support of 50 per cent, up to a cap of $50,000.

The requirement for contingency plans will help farms "build resilience through the development of a deployable contingency plan to handle similar future incidents", the AVA told The Straits Times. "During the recent incident, farmers who heeded AVA's alert and advice took quick actions to save their fish stocks and were able to avert significant losses," the spokesman said.

The AVA alerted fish farmers to elevated plankton levels about two weeks before the bloom. They were advised to take precautions, like using canvas bags to protect the fish from the external environment, harvesting fish early and moving them to unaffected areas.

Mr Gary Chang, 58, whose fish farm is located near Pulau Ubin, lined his net cages with canvas bags and used a simple filtration system to maintain the water quality during the plankton bloom. He managed to cut losses this year to $30,000, compared to $300,000 last year.

"In the long run, you'd need to do something more than that. We could study what other countries have done to deal with the recurring plankton blooms," he said.

Canvas bags are not without their shortcomings. For one thing, preparation is neededahead of the transfer of fish from cages to bags, said Mr Chang. The fish need to be starved a week beforehand to reduce the amount of waste they produce, which will accumulate in the bags and become harmful to the fish.

President of the Fish Farmers Association of Singapore Timothy Ng said while the AVA condition this year has "good intentions", the effectiveness of the backup plans has to be proven, especially when huge quantities of fish are at risk.

The AVA said it will conduct training on what makes a good contingency plan and how to tap mitigating measures.

Last month, the association sent the AVA a proposal listing possible solutions to tackle the effects of a plankton bloom.

They include clay flocculation - the spraying of clay particles into the water so that they can bind to the plankton before they clump together and sink to the sea floor.

The AVA said it is reviewing the proposal, and will "explore the possibility of conducting studies on the proposed options with agencies and experts".

Fish farmer Frank Tan, who lost 120 tonnes of fish in the last incident, said the help is good news. "The Government wants to push farmers to have higher resilience. Everyone has to play a part," he said.