Tag Archives: sok kwu wan

Ten Green Sea Turtles Returned to The Sea

The Agriculture, Fisheries and Conservation Department (AFCD) released 10 green turtles seized in an earlier enforcement action in the southern waters of Hong Kong on Monday (November 15). 

The 10 green turtles are among the 35 green turtles and one hawksbill turtle seized from a fish raft in Sok Kwu Wan Fish Culture Zone on September 30. The turtles were assessed by vets at Ocean Park Hong Kong (OPHK) and have been looked after there with constant monitoring and veterinary care.

 An AFCD spokesman said, “This is the largest batch sent to OPHK since it started helping to provide care for rescued sea turtles. The department is thankful to OPHK for making special arrangement to accommodate the sea turtles and the veterinarians and staff for taking care of them.”

The 10 green turtles weighed from 9.6 kilograms to 23kg and measured about 45 centimetres to 61cm in shell length. All of them were considered to be in good condition and ready to be returned to the sea. The AFCD will continue to work together with OPHK on the other turtles seized in the operation and release them in batches later according to their health condition and the weather.

A green sea turtle being fitted with tracking devices

Before the turtles were released to the sea, the AFCD tagged each of them with a microchip and Inconel tags for future identification. Satellite transmitters were also attached to the carapaces of some of the turtles. By tracking the movement and feeding grounds of green turtles in the sea, the AFCD can collect data for formulating appropriate conservation measures and share its findings with other conservation authorities for the better conservation of sea turtles.

Members of the public are urged to report any sighting of sea turtles to the department via 1823. 

AFCD Seized 36 Live Sea Turtles from Lamma

The AFCD seized 36 live sea turtles from a fish raft at Sok Kwu Wan Fish Culture Zone on Friday (September 30).
Upon receipt of a report of sea turtles found on the fish raft from the Police, the AFCD officers were deployed to the scene for investigation and they seized 35 green sea turtles and a hawksbill turtle.
All the sea turtles were sent to Ocean Park Hong Kong for observation and detailed veterinary assessment and follow-up investigation by the AFCD is ongoing.

To report suspected irregularities, call the government hotline at 1823.

Ciguatera: Another Good Reason To Avoid Large Reef Fish

Hongkongers love their seafood – a quick glance at the local restaurants scene will more than proove that point. Per capita HK has one of the highest seafood consumption rates in the world. For many locals, expats and tourists a trip to Sok Kwu Wan on Lamma for a seafood meal would not be complete without a big steamed grouper (also called garoupa). But aside from concerns about over-fishing and sustainability, eating these fish can be a health risk, too. That is because these large reef fish are more likely than others to give you ‘Ciguatera fish-poisoning‘. Ciguatera (‘see-gwa-terra’) is a food born toxin harbored by large reef fish. Originally the toxin (CTX) comes from a microscopic organism called Gambierdiscus. Gambierdiscus is a dinoflagellate – a single-called organism with a thin shell and two beating hair-like whips called ‘flagella’ that move it through the water.

Marine plankton Gambierdiscus toxicus can produce ciguatera toxins (Image taken by Dr. Maria A. Faust, Department of Botany, National Museum of Natural History, Smithsonian Institution, Washington D.C., U.S.A.)
Marine plankton Gambierdiscus toxicus can produce ciguatera toxins (Image taken by Dr. Maria A. Faust, Department of Botany, National Museum of Natural History, Smithsonian Institution, Washington D.C., U.S.A.)

Gambierdiscus sticks to coral, seaweed and algae in tropical and sub-tropical regions (like HK) and is eaten by smaller fish feeding on the coral and algae. These fish in turn are eaten by predator fish and so the toxin moves up the food chain, finally accumulating in its greatest concentration in the large reef fish.

Figure_2_1_sTissues like the roe (fish eggs), head, skin and insides are particularly good at concentrating CTX. CTX is odourless and tasteless and very heat-resistant – so conventional cooking will not destroy or inactivate the toxin.

So how bad is CTX poisoning?

Ciguatera causes a combination of gastrointestinal, neurological and cardiovascular symptoms. The gastrointestinal symptoms include nausea, vomiting, abdominal pain and diarrhoea. That might not be that bad, right? But the cardiovascular symptoms are more serious: a slowing of your pulse to under 60 beats per minute (sinus bradycardia) and low-blood pressure (hypotension) which can be life-threatening but can also be treated. The common neurological symptoms include a sensation of tingling, tickling, pricking, or burning of a person’s skin, numbness of lips, tongue and the four limbs, reversal of hot-cold sensation, muscle pain, muscle weakness, joint pains, itching and fatigue and these symptoms can last for weeks or even months.

CTX in Hong Kong

Because ciguatera is a matter of food safety the HK government requires by law that the reporting of all diagnosed or suspected cases and as a result there are some good statistics on ciguatera in Hong Kong. From 1988 to 2008 there were between 3 and 117 outbreaks annually causing between 19 and 425 people to fall ill. Groupers were responsible for almost 60% of those cases, with snappers causing another 32%. The rest of the cases were caused by moray eels, triggerfish, parrot fish and other reef fish. Past records of ciguatera fish poisoning cases in Hong Kong show that the following fish are more likely to contain ciguatoxins: Moray Eels, Potato Groupers, Speckled Blue Groupers, Tiger Groupers, High Fin Groupers, Hump Head Wrasses, Areolated Coral Groupers, Black Saddled Coral Groupers, Lyretails, Black Fin Red Snappers, Flowery Groupers and Leopard Coral Groupers.

HK Ciguatoxin poisonming cases 1989 – 2008

The most recent suspected case was in September 2014 when a 38-year old man became ill. Before that 19 people aged between 23 and 71 became ill after a shared seafood meal on Lamma in June 2013.

Ciguatoxin cases reported in HK
Ciguatoxin cases reported in HK

Ciguatoxin is very difficult to detect in fish samples so quality control measures are very difficult to implement and suspected cases are often not confirmed because either a sample of the eaten fish is not available anymore or chemical test are not able to detect the ciguatoxin well enough.

How to avoid CTX poisoning

To avoid this nasty CTX poisoning your best bet is to avoid large reef fish especially groupers. Any reef fish over 2 kg in weight is especially risky. And if you do chose to eat such fish stay away from the high-risk body parts of head (sorry, no more sought-after cheek meat), insides, skin and roe (eggs).

coralfish_e

The HK government’s guidelines for the prevention of CTX poisoning are:

  • Buy coral reef fish from reputable and licensed seafood shops. Do not buy the fish if in doubt.
  • Consume less coral reef fish, especially marine fish over three catties (1.5 kg).
  • Only eat small amounts of coral reef fish at any one meal and avoid having a “whole fish feast” in which all the dishes come from the same big coral reef fish.
  • Avoid eating the head, viscera, skin, and roe of coral reef fish which usually have higher concentration of toxin.
  • When eating coral reef fish, avoid alcohol, peanuts or beans as they may aggravate ciguatera poisoning.
  • If you are suffering from ciguatoxin poisoning you should refrain from coral reef fish. The intoxication will sensitize patients and they will suffer from ciguatoxin poisoning even if they are exposed to a lower concentration of toxin.
  • Seek medical treatment immediately when symptoms of ciguatera fish poisoning appear. The unfinished fish should be brought to FEHD (Food & Environmental Hygiene Department) for testing.
  • There is HK Centre for Food Safety Info-Poster on Ciguatera Fish-Poisoning Prevention you can download here.

 

Interesting side notes
  • Ciguatoxins are actually a group of about 20 chemically related toxins. The most potent of these is Pacific-CTX-1 (PCTX-1) which is found in the Pacific Ocean.
  • Ciguatera fish-poisoning was described as early as 600 BC by the Chinese and Captain James Cook’s log details effects felt by his crew on a voyage to Tahiti in 1774.
  • The clinical description of the syndrome came from Portuguese biologist Don Antonio Parra and were published in Havana in 1787. Parra said, “some [fishes] cannot be eaten because they are `ciguatos’ and some others are suspicioned because they carry with them the poison..I can speak from personal experience, because on 15 March 1786, twenty-two of us ate a Cubera, and we all developed those symptoms to a greater or lesser extent. All were prostrated, but each one was suffering various types of discomfort, although the most common type of difficulty was the extreme exhaustion accompanied by more or less pain. I observed that I had extreme difficulty in breathing, which caused great pain and a feeling of suffocation. My tongue became rough and I developed a sour taste in my mouth.”
  • There is commercially available test kit for consumers called Cigua-Check®, however studies have shown it to have a lower than desired reliability and I do not encourage its use over the HK government’s advice cited above.

Huge Waterspout Off Lamma

Reports and pictures are circulating of a waterspout off Lamma yesterday at around 6:00 in the evening (12/08/2014). The waterspout estimated to have been a few hundred meters high was spotted by anglers fishing near Sok Kwu Wan. Thanks to the widespread use of camera phones, we actualy have a photo of it to (featured). 

The Hong Kong Observatory’s data showed that the area had strong convective activity, raising the chance of “waterspouts.” 

Waterspouts are most common in June and July in Hong Kong waters and have occurred several times in recent years, see earlier post on waterspouts in Hong Kong.

 

One pictures taken as far away as Ocean Park even captured it.

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The waterspout off Lamma seen from Ocean Park. (Image from Facbook user Yuri Wong)