Daily Decay (28th February 2018)

Daily Decay (28th February 2018): Eeltail Catfish (F. Plotosidae) @ Changi

This was one of the many casualties of a fish mass death in February 2014, caused by a harmful algal bloom in the eastern Straits of Johor. Three species of Eeltail Catfish are present in Singapore waters – the Striped Eeltail Catfish (Plotosus lineatus), Black Eeltail Catfish (Plotosus canius), and White-lipped Eeltail Catfish (Paraplotosus albilabris). Due to the decomposed state of this carcass, it’s not clear which species it is.


Black Eeltail Catfish (Plotosus canius)
Pasir Ris, 22nd February 2015

This Black Eeltail Catfish was one of the many casualties of yet another fish mass mortality event that was triggered by a harmful algal bloom.

NEA cleaners cleaning up the dead fish washed up on Lim Chu Kang jetty. Minister for the Environment and Water Resources Vivian Balakrishnan yesterday said the bloom will pose a “real challenge for long-term fish farming in that area”. Photo by Lau Fook Kong

Plankton bloom causing fish deaths ‘likely to recur’
AVA and farmers must discuss best way to tackle challenge: Vivian
By Carolyn Khew, 9th March 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 (F. Ariidae and F. Plotosidae) and Mullet (F. Mugilidae), 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 (Pampus sp.) 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.”

Source: The Straits Times

Mass fish deaths off Singapore coast spark concern
By Tessa Wong, 6th March 2015;

Last Sunday morning, Bryan Ang woke up onboard his floating fish farm on the Johor Strait between Malaysia and Singapore to find nearly all his stock had died.

“We woke up and saw all the fish floating belly-up,” he said. “It’s devastating.”

He was not alone. Hundreds of tonnes of fish – both farmed and wild – died over the weekend in the eastern part of the strait. Fish farmers lost hundreds of thousands of dollars in stock overnight.

Floating out at sea and washing up on the beaches and mangroves, dead sea creatures began to appear, from sea snakes and seahorses to squid and moray eel.

Nature guide and environmental biology student Sean Yap – who supplied some of these pictures to the BBC – said he was jogging along the eastern Pasir Ris beach on Saturday evening when he smelt a foul stench.

It came from what he described as a “mass grave” – thousands of dead fish washed up on shore.

“There were cleaners present on the shore on Sunday morning to deal with the carcasses, but when we returned at night the high tide had brought in a new batch of bodies.”

The environmental authorities said the deaths were due to a plankton bloom, where a species of plankton multiplies rapidly, damaging the gills of fish. It can be triggered by sudden changes in temperature, high nutrient levels in the water, and poor water circulation.

Government agencies were unable to provide the BBC with figures, but said they were “concerned” about the potential impact on marine biodiversity and were taking steps to investigate and help farmers clean up.

Mr Yap said he found it alarming that even species such as catfish and burrowing gobies, which are considered to be more resilient, were found dead. The deaths of “invertebrates like worms is also alarming, as it may mean that the base of the food chain is affected,” he said.

There have been similar mass fish deaths in the past five years. This time round, the authorities had given an early warning to farmers – giving them time to move their stock into protective nets, activate pumps to keep the water moving or even float their entire farm to safer areas.

Some managed to save their stock, but few had anticipated the intensity of the plankton bloom nor how quickly it would strike, killing the fish en masse within hours.

Several fish farmers told the BBC that rapid development in the western part of the strait in Johor, the Malaysian state closest to Singapore, was one of the factors affecting the water quality.

“The plankton bloomed this fast because the nutrient content in the sea is so high. And where are all these nutrients coming from? Land reclamation in Malaysia,” said Frank Tan.

But tiny Singapore has also reclaimed parts of its northern coast, and dammed up estuaries in the northeast to create reservoirs. It has pumped millions of dollars into the fish farming industry to boost its domestic food security.

Latest government figures show there are now 117 fish farms in waters surrounding the island, spread out over 102ha – twice the amount of space compared to a decade ago.

Dr Lim Po Teen, a marine scientist with the University of Malaya, said climate change was in part to blame for the blooms, by affecting temperatures and weather patterns.

“But on a local level, you can see the number of farms increasing in the last few years,” he said, which is directly increasing the level of nutrients in the water from fish food and waste.

“We need to have very strict controls and improve the water circulation.”

Some of the farmers reeling from the loss of their stock were considering moving away altogether to less troubled waters.

“This weekend’s incident was the worst I’d ever seen. Everyone is horrified.” said Mr Tan. “We may have to relocate now.” He said he was eyeing spots to the south of Singapore.

But many of the farmers were hoping to get through the year by restocking with new fry and selling what little they could save of their remaining stock. Said Mr Ang: “We are trying to explain to people that our fish is still edible. We just need to regain people’s trust.”

Source: BBC News

Mass Marine Mortality at Pasir Ris
By Sean Yap, 28th February 2015;

For the past few years around this time of the year there have been occurrences of mass fish deaths on our northern shores. This year is no exception. Ria was here earlier as well, and has done a comprehensive blog post about the situation. I’m just posting photos of cool dead things. I know I don’t sound sad but I am, kay 😦

So Chinse New Year is over, and the food guilt finally set in so I decided to try and run to work some of the sin off. As soon as I hit the path however, my nose was immediately assaulted by a foul stench. I had seen some of my friends posting about fish deaths on Facebook, so I decided to go see for myself what the situation was like (totally not an excuse).

The first stop was a breakwater, and LO AND BEHOLD, I was greeted with a friggin mass grave.

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Source: Nature in a Concrete Jungle

Casualties include eels, pufferfish and frogfish (which I’m seeing for the first time – sad it has to be this way). Cephalopods were not spared either.

Source: Sean Yap Instagram

Some tentative identifications:
Left: Estuarine Moray Eel (Gymnothorax tile), with Striped Eeltail Catfishes (Plotosus lineatus), Kops’ Glass Perchlets (Ambassis kopsii) and Telkara Glass Perchlets (Ambassis vachellii), and possibly a Threespot Damselfish (Pomacentrus tripunctatus).
Right (Top): Cuttlefish (Sepia sp.) with Telkara Glass Perchlets.
Right (Centre): Spotted-tail Frogfish (Lophiocharon trisignatus).
Right (Bottom): Spotted Green Puffer (Tetraodon nigroviridis).

Dead fish update: Pasir Ris, Seletar Dam, Sembawang
By Ria Tan, 27th February 2015;

Today I had a quick look at the western shores of Pasir Ris. There were a few large dead fishes and many smaller ones. All appeared to be wild fishes. Also, dead cuttlefishes and horseshoe crabs. I didn’t see any dead farm fishes. Sightings of dead fishes at Seletar Dam (Benjamin Li) and Sembawang (Tan Sijie) were also shared recently.

Timothy Hromatka, a fish farmer off Ubin also shared more about the recent fish deaths on the farms.

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Source: Wild Shores of Singapore