Rough Golden Toadfish (Lagocephalus lunaris)
Pulau Ubin, 11th March 2018
Photograph by Sean Yap
New record of Blue-spotted Pufferfish (Arothron caeruleopunctatus) in Singapore
Location, date and time: Johor Strait, beach at Pasir Ris Park; 1 March 2015; around 1030 hrs.
Observation: A large individual of about 70 cm total length was found dead and stranded on a sandy beach. It was found alongside large numbers of dead fish, including members of its congeners Arothron immaculatus, A. reticularis, A. stellatus and A. mappa. The accompanying picture shows the fish on its side. It appears to have been dead for at least one day.
Remarks: The featured pufferfish was apparently a casualty of a plankton bloom in the Johor Strait since 28 February 2015 that killed large numbers of fish there (Cheong, 2015; Khew, 2015). This specimen represents the first record of Arothron caeruleopunctatus in Singapore (Fowler, 1938; Kelvin K. P. Lim, personal communication). It is distinguished from the similar looking Map Pufferfish (Arothron mappa) in being yellowish-brown on its dorsum; having dark-coloured rings around its eye; small blue spots on its head, body and fins; and a black patch with white spots at the base of its pectoral fin. It attains a maximum size of about 80 cm and occurs from the Réunion and Maldive Islands throughout the East Indian region to New Caledonia and Marshall Islands, northwards to Japan (Allen & Erdmann, 2012: 1086).
- Allen, G. R. & M. V. Erdmann, 2012. Reef Fishes of the East Indies. Volume III. Tropical Reef Research, Perth,
Australia. pp. 857-1292.
- Cheong, K., 2015. Mass fish deaths overnight hit Changi farmers hard. The Sunday Times. 1 March 2015: 8.
- Fowler, H. W., 1938. A list of the fishes known from Malaya. Fisheries Bulletin. 1: 1-268.
- Khew, C., 2015. Fish farms may move from Changi after mass deaths. The Straits Times. Wednesday, 4 March 2015: A3.
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
Thousands of dead fish spotted at Pasir Ris Beach. Photo: Sean Yap
More dead fish, marine life at Pasir Ris beach
By Siau Ming En, 2nd March 2015;
Following the mass fish deaths that affected farmers along the eastern Johor Straits over the weekend, other marine wildlife, including species such as Frogfish (F. Antennariidae), horseshoe crab and pufferfish (F. Tetraodontidae), have washed up on Pasir Ris beach.
The Agri-Food and Veterinary Authority (AVA) said the post-mortem results of fish samples collected from the affected farms indicated the fish had died as a result of gill damage caused by plankton, which are micro-organisms found in seawater. They can bloom or multiply quickly in a very short time, draining the seawater of oxygen.
“Laboratory tests conducted so far did not detect marine biotoxins in the fish,” it said.
Local fish farmers said the fish deaths on Saturday morning were worse than those during a similar event that happened at around the same time last year.
Mr Teh Aik Hua, who owns two fish farms in Sembawang and Pasir Ris, said he is left with only 1 per cent of his fish stock, compared with a 20 per cent survival rate last year.
“The problem is more serious this year. Even wild fish were found dead,” he added.
With the recent hot and dry weather, which is expected to stretch into this month, Mr Teh said about 40 per cent of his fish stock at the Sembawang farm has also died from the increasing salinity of the water.
Another fish farmer, who only wanted to be known as Simon, painted a similar picture. Nearly all his fish were wiped out this time, whereas last year, half of his stock had survived.
Around this time last year, there were fish deaths at 34 fish farms along the East Johor Straits and five farms along the West Johor Straits. About 160 tonnes of fish were found dead because of low levels of dissolved oxygen in the waters or a plankton bloom, or both, as well as the hot weather.
In response to queries, the AVA said fish harvested from local farms are safe for consumption.
The largest supermarket chain here, NTUC FairPrice, also assuaged consumer concerns, saying it imports fish from local farms that are accredited by the AVA, which has taken steps to ensure only live and healthy fish are being supplied.
FairPrice, which has more than 120 outlets, said some of these fish farms, including those in Pasir Ris, Changi, Lim Chu Kang and inland Kranji, have taken steps to move their harvests to other locations and increase the aeration of the water.
“As such, our supply of local fish remains unaffected,” said a FairPrice spokesperson.
High tide at night brought more carcasses in, at least 7 puffers this time. This one should be the Map Puffer (Arothron mappa).
Source: Sean Yap Instagram
OMG all these giant inflated puffers of different species. WTH is going on.
Source: Sean Yap Instagram
This one appears to be a White-spotted Puffer (Arothron hispidus).