Artificial Reefs for Brothers Marine Park Proposed

On the 29th of June the government gazetted a proposed plan for artificial reefs to be built inside the Brothers Marine Park, to improve the habitat and boost fish numbers. The artificial reefs will cover around 0.7 hectares inside the 66-hectare marine park off Lantau to the east of the airport.

The works are tentatively scheduled to start at the end of 2018 and should be completed by 2019.

The marine park has been identified as an important habitat for endangered Chinese White Dolphins, and a spawning ground for commercially important fish species.

Grouper Reef by Reefmaker deployed off Mexico Beach, Florida USA. Reproduced under cc-by-sa 3.0
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Vietnam Also Guilty of Destroying Reefs in S. China Sea

It is not just China destroying reefs in the South China Sea by reclaiming land to form island outposts to boost territorial claims. Vietnam is also reclaiming land by dumping enormous amounts of sand on two reefs destroying coral communities and changing the local ecology and likely adversely affecting fish stocks.

The photographs, shared with Reuters by Washington’s Center for Strategic and International Studies (CSIS), show an expansion of the land area of Vietnamese-controlled Sand Cay and West London Reef in the Spratly archipelego and the addition of buildings.

 

Sandy Cay (largest islet in the image) is small islet in the South China Sea occupied by Vietnam. it is visited by seabirds and was home to a rich marine diversity.
 

The director of CSIS’s Asia Maritime Transparency Initiative (http://amti.csis.org/), said the work included military installations and appeared to have started before China began a flurry of reclamation projects last year. “On one site, it has constructed a significant new area that was formerly under water and at another it has used land reclamation to add acreage to an existing island,” Rapp-Hooper said.

The images showed that Vietnam had reclaimed about 65,000 square meters (699,654 square feet) of land at West London Reef and 21,000 square meters (226,042 square feet) at Sand Cay. This compared to 900,000 square meters (9.6 million square feet) reclaimed by China at a single reef, Fiery Cross.
 
Satellite images show that since about March 2014, China had conducted reclamation work at seven sites in the Spratlys and was constructing a military-sized air strip on one artificial island and possibly a second on another.

It appears that claimants to the South China Sea have entered into a land building race that destroys ecology and depletes fish stocks as a result. There can be no real winners in such a race – everybody will lose.

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.

Ciguatera Fish Poisoning Case Reported in Hong Kong

The Hong Kong Centre for Health Protection (CHP) of the Department of Health is investigating a suspected ciguatera poisoning case affecting a 38-year-old man. The patient, with good past health, developed symptoms of ciguatera poisoning including facial and tongue numbness, skin itchiness over the forehead and the neck, abdominal pain and diarrhoea about two to three hours after eating a marine fish at home on September 24.
He attended the Accident and Emergency Department of Pamela Youde Nethersole Eastern Hospital on September 25 and was subsequently admitted. He is now in stable condition. The CHP’s investigations are ongoing.

Ciguatera fish poisoning is not uncommon in tropical areas. More than 400 species of fish have been implicated in this food borne illness that’s relatively common in several areas of the world. This toxin is the result of the accumulation of marine algae and the toxins they produce passing up the food chain. These marine algae hang on to dead coral and seaweed. They are then eaten by herbivore fish which are subsequently eaten by predatory reef fish which concentrates the toxin in its tissue.
The toxin accumulates in the fish body, in particular in internal organs, through eating small fish that consumed toxic algae in coral reef seas. A larger fish is therefore more likely to carry higher amounts of the toxin. However, it is not easy to tell from the appearance of the fish whether it contains the toxin. The reef fishes are more likely to get contaminated during storms and other turbulence.

People affected may show symptoms of numbness of the mouth and the limbs, vomiting, diarrhoea, pain in the joints and muscles. An unusual characteristic that is common in ciguatera is temperature reversal. This may be seen from 2 to 5 days after eating the fish. Hot objects seem cold and cold objects can give a shock-like sensation. There have been serious injuries because a person was unable to recognize extremely hot sensations. Other odd symptoms are food may taste metallic and teeth may seem painful or loose.Most people affected by ciguatoxin would recover without long-term health effects, but if excessive toxins are consumed, the circulatory and nervous systems can be affected.
Symptoms may come back after ingesting certain foods and drinks; alcohol, caffeine, nuts and fish.
There are no laboratory tests to diagnose this disease and it’s based on clinical symptoms and a history ofeating an offending fish.

Ciguatera fish poisoning is the most common form of neurotoxin poisoning associated with the consumption of fish in Hong Kong. From 2000 to 12 June 2013, the Centre for Food Safety had received 284 referrals of CFP from the Department of Health (see Figure). A total of 867 persons were affected.

IMG_7061.JPG

Number of ciguatoxins cases from 2000 to 2013 (Up to 12 June 2013)

The reporting of CFP occurred year round. However, it was observed that over 60% of total cases were reported in March to July of the year. The number of person affected also provided similar observation.

Different kinds of coral reef fish caught in the wild were known to be associated with CFP. Black fin red snapper, Tiger grouper, Lyretail, Leopard coral grouper, Areolated coral grouper and Moray eel were the top six common types of fish linked to CFP, accounting for over 50% of CFP cases. Farmed fish which was usually fed by formulated pellet or trash fish was not likely the source of toxins.

IMG_7062.JPG
Fish commonly involved in CFP from 2000 to 12 June 2013.

The toxin cannot be destroyed by cooking. To prevent ciguatera fish poisoning, you should observe the following measures:

* Eat less coral reef fish;
* 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, skin, intestines and roe of coral reef fish, which usually have a higher concentration of toxins;
* When eating coral reef fish, avoid consuming alcohol, peanuts or beans as they may aggravate ciguatoxin poisoning;
* Seek medical treatment immediately should symptoms of ciguatoxin fish poisoning appear; and
* Coral reef fish should be purchased from reputable and licensed seafood shops. Do not buy the fish when the source is doubtful.

Hong Kong Centre for Food Safety Ciguatera page

Hong Kong gets its ASC sustainable seafood guide

The latest edition of the Sustainable Seafood Guide includes information for seafood consumers in Hong Kong shopping for responsibly farmed fish.

For the first time, the guide educates on the Aquaculture Stewardship Council (ASC) logo for responsible aquaculture.

“This is a great step forward in informing Asian seafood customers about the ASC. By choosing seafood with the ASC logo, shoppers can make a difference and help protecting oceans, vulnerable marine environments and local farm communities,” said ASC’s CEO Chris Ninnes.

There are currently 1,120 ASC certified seafood products available in 37 countries across the globe.

“Not only is our market share growing in Asia, but we have an expanding base of certified farms in the region including Indonesia, Malaysia, Taiwan and Vietnam; and we anticipate strong future growth,” Ninnes said.

The Hong Kong Sustainable Seafood Guide is produced by World Wildlife Foundation (WWF) Hong Kong.

The methodology that the guide is based on has been developed by WWF, Seafood Choices Alliance, North Sea Foundation and the Marine Conservation Society. Fish guides can now be found in 18 countries around the globe.

The ASC on-pack logo was launched in 2012. All ASC labelled products can be traced back through the entire supply chain to a responsible managed fish farm.

Source: Undercurrent News, 9/7/2014

Human Error Kills 59 Fish at Ocean Park

In the early morning of the 3rd of July (2014) 59 fish were found dead at Ocean Parks aquarium,

including a breeding pair of bamboo sharks, two rays and some other fish .

The park said the event was caused by human error, and that the employees involved would receive disciplinary action and that procedures would be reviewed additional sensors installed. An inquiry found that the deaths were the result of a lack of oxygen in the water which lead to the fish suffocating. Normally procedures for tank maintenance allow staff to switch of the wave generator that oxygenates the water for up to 6 hours without causing harm to the fish. In this instance it was switched off for water treatment projects to be carried out, but staff failed to then properly restart it.

Ocean Park has not made a press release available.

Source: RTHK, 14/7/2014

Fish No. 5: Conger (Pike) Eel – Muraenesox cinereus

Scientific Name: Muraenesox cinereus
Common Names: Conger Eel, dagger-tooth pike conger, conger pike, pike eel, 海鰻 or 海鳗 or 海鳗 in Mandarin Chinese, 海鰻 in Taiwanese, hamo in Japanese, Pindanga in Tagolog, .
Origin: China

As the last thing the world needs is another “food blog” I decided to concentrate these fish posts more on the fish themselves, their marine biology and sustainability and fisheries. That said lets turn to the Conger Eel Muraenesox cinereus.

Its a member of the Eel group (which has 600 species!) and lives on soft bottoms down to a depth of about 100 metres where it feeds on small bottom fish and crustaceans. Its also sometimes found in estuaries and can even enter freshwater environments. They commonly reach length of 150 cm, but may grow as long as 200 cm. It occurs in the Red Sea, on the coast of the northern Indian Ocean, and in the East Pacific from Indochina to Japan. It has also invaded the Mediterranean through the Suez Canal. Conger eel is a major commercial species, with annual catches reaching about 350,000 tonnes in recent years. The countries reporting the largest landings were China and Taiwan. It is a traditional food in Japanese cuisine, where it is known as hamo and is wild caught but also cultured. Conger eel meat has been used as an ingredient in creating crab sticks.

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It is marketed mainly fresh and is also used as bait for shark fishing. In China dried conger eel is apparently popular with eels 1m in length being split down the middle, gutted, washed in saline solution and then air dried – though I have never seen one in Hong Kong (so far). According to the traditional chinese medicine Wiki (TCM Wiki) the spawn – or eggs – (Hai Man Luan) of the Conger Eel is used to strengthen the body by means of tonics which reduce weakness, anemia, cirrhosis, hepatic adipose infiltration, neurasthenia. This is done by baking it to yellow, and then pounding it into powder, then taking 6~12 g of the powder orally. Another source (The Encyclopedic Reference of Traditional Chinese Medicine edited by Yang Xinrong) says it is used to with a detoxifying effect to treat malignant skin boils, scabies, and hemorrhoids with anal fistula (if you’re anything as curious as me when you read “anal fistula” …let me save you the trouble, of searching for it: here is the link to Wikipedia explaining it – enjoy…yuk!). 
For the expats reading this : according to my 1962 book that is the inspiration for the fish posts, ‘Europeans’ (I think this is meant to include Americans) have only ever eaten 3-4 local fish species in Hong Kong. So should you bother expanding your food horizon with conger eel? Is this a good fish to eat? I can tell you it tastes just very nice with firm white flesh, but there are a lot of tiny bones that pretty much spoil the experience – for me anyway. From what I have read a lot of Chinese fish balls contain conger eel – probably along with other fish species – because ground down to paste and kneaded into fish balls the tiny bones are no longer a problem. So if you have ever eaten fish balls (perhaps in soup) , chances are you have had already tried conger eel without knowing it.
But the big question is – should you eat it? Is it sustainable? What does the WWF Seafood Guide say? It says – nothing, a big fat nothing. Conger eel is not mentioned at all. Zip. So now what? I have contacted Park’n’Shop again to get some more details on how they sourced their fish. But while we wait for an answer, I had a look around the internet to see what info is available on conger eel fisheries in China or Southeast Asia in general. According to the UN Food and Agriculture Organization (FAO) the catches of conger eel (and most other fish species) in China have skyrocketed in the last 20 years, going from 40,850 tonnes in 1990, to 372,704 in 2011! In Japan, the conger eel is caught by longlines and then transferred to fish farms to mature and they are making attempts to produce spawn so that they can farm this fish in future.  And that’s about all you can find on the internet!
So we will have to wait and see what Park’n’Shop says. If the fish is caught by trawling, its a definitive no-no so AVOID. And if it is farmed or caught by lines, that’s is a bit better, but no guarantee that it is sustainable, so “THINK TWICE”. In the absence of information my verdict for now is a cautionary “AVOID”.