The Hong Kong government has given a press release about the deaths of two men from Vibrio vulnifcus on the 20th of June this year (2012) (press release). V. vulnificus is a marine bacteria which can cause infection by ingestion (seafood) or through open wounds when swimming or wading in infected waters or via puncture wounds from the spines of fish such as tilapia. It prefers warm seawater or brackish (mixed fresh- and seawater) and occurs worldwide in warm salt-bearing waters and can be present in infected shellfish. It is a relative of the bacteria that causes cholera (Vibrio cholerae).
The infection presents itself with symptoms including vomiting, diarrhea, abdominal pain, and a blistering dermatitis. In people with compromised immune systems, V. vulnificus is eighty times more likely to spread into the blood stream, when it can cause severe symptoms including blistering skin lesions, septic shock, and even death . Severe infection may occur regardless of whether the infection began via contaminated food or via an open wound. There is no evidence for person-to-person transmission.
One of the two men was found to have consumed raw mantis shrimp in an investigation. I would stress though that there seems to be no reason to assume that we are more at risk in HK than anywhere else. Infections also occur in US coastal waters, Japanese coastal waters and anywhere where infected shellfish is consumed. Given that shellfish is cold-stored and flown around the world in todays world, infections can happen almost anywhere. If you are concerned, the press release issued the following safety guidelines for the public:
People are reminded to adopt the following measures to prevent necrotizing fasciitis and Vibrio vulnificus infection:
* Avoid exposure of open wounds or broken skin to seawater or salty water;
* Wounds should be thoroughly cleaned and properly covered;
* Wear thick rubber gloves when handling raw shellfish;
* Cook seafood, especially shellfish (e.g. oysters, clams, mussels) thoroughly; and
* For shellfish, boil until the shells open and avoid cross-contamination of ready-to-eat food with raw seafood.
Patients should seek medical advice promptly if they develop symptoms and signs of infection such as increasing redness, pain and swelling.
With the rainy season now in full swing, it’s time to talk colors. Water color that is, and I don’t mean painting, I mean the color of the sea in HK.
It’s actually not the same everywhere, because if you live in Lantau Island on the western side, you are closer to the Pearl River Estuary which carries a lot of mud and silt down into the sea. That makes HK’s western waters murky and muddier, and because the Pearl River also carries a lot of minerals and nutrients down into the Sea, it makes for much better growing conditions for phytoplankton – microscopic algae that float around in the sea. That tends to turn the water color green or yellow, too.
But the eastern side of HK is a different story. Here the water is more oceanic and blue-green because there is no big source of mud and nutrients. Corals love warm, nutrient-poor and sunlit water, so you find them more on the eastern side of HK – basically as far away as they can get from the big rivers.
So what’s all this got to do with the rainy season? Well, a big tropical downpour washes soil, nutrients as well as all sorts of rubbish off the mountains and into the sea…anywhere, so river or no river, the water goes yellowy-green.
If you are a diver, this gives you two rules of thumb for visibility in HK waters:
– East is best, west is worst
– don’t bother diving after rain: the more rain, the longer you have to wait for decent visibility to return. For your typical typhoon I estimate at least 5 days.
Lucky I read the paper this morning! It would appear at first that shark conservation is being taken seriously in China with a new ban on shark’s fin at government banquets. As many people know government banquets – or any banquets for that matter – in China are BIG and frequent occurrences!
So this ban would appear to be great news not only because less sharks fin is going to be consumed in China, but also because it shows that more attention is now being given to shark conservation in China.
Sadly, as the newspaper pointed out, too, the reality is somewhat different. Faced with crippling provincial government debts in some areas and overspending in most,the real reason for the ban is cost savings. It was only a few months ago that Chinese officials were given mew guidelines on how many dishes to order per table at banquets to reign in the excesses. It would appear that shark conservation is not high on the agenda at all. And with rising prosperity in China and a ferocious appetite for luxuries for the nouveau riche, I doubt very much that shark’s fin consumption will drop much.
Still its a small step, and it might lead to more.
To show your support for shark conservation, sign HK SharkFoundation’s Petition and visit their website for more information and to help the cause.
There is a lot of information on the internet about the Sousa chinensis, the Indo-Pacific Humpback dolphin, also known as the Chinese White Dolphin or the Pink Dolphin, so I won’t repeat any of it here. Instead here are some links to organizations and people that deal with the topic full-time:
Meet an old friend of mine, the Arabian cowrie known by its scientific name as Mauritia arabica (Linnaeus, 1758). When I started my first website as a teenager this was the first animal to feature and it’s still one of my favorites. I have always loved the fine lines and curves on the shell that resemble Arabic script and give the shell its scientific name “arabica”.
They are pretty wide-spread ranging from South Africa all the way up East Africa , the Red Sea and Persian Gulf, India, Bangladesh, Myanmar, Thailand, Malaysia, Vietnam all the way across the Indonesian and Philippine islands and southern coast of China, down to Papua Guinea and northern Australia. It lives in shallow water near corals at cavern entrances and overhanging boulders or even under rocks where it feeds on algae during the night.
In Hong Kong if you know where to look its fairly easy to find them, too. Last weekend I was walking along a small beach in Ha Mei Wan (western side Lamma Island) south of the power station and spotted several bunches of 10 or more of them. The tide was very low which exposed many of them to the air and huddled together in shady and moist spots of overhanging boulders near the water line.
Another good place I have found this species is snorkeling among coral covered boulders at Shum Wan on Lamma Island. These guys like to cling to the overhangs of boulders near the sandy bottom.
I have inserted a picture from WikiCommons for this post, but for some really excellent images have a look at this site where you can see all the varieties of this little beauty from multiple angles: http://www.cypraea.eu/species/cypraea_arabica.htm
PLEASE, DO NOT COLLECT LIVE SPECIMENS OR BUY THEM FROM SHOPS OR ONLINE: There are many websites that sell seashells for profit and to get a perfect shell for selling, most collectors will take live specimens. They will put them in 100% alcohol to make them swell out of their shell and die so that the shell can be stored without smelling of rotting snails. But why kill such a beautiful animal simply to keep in a box and show off? If we all do that there won’t be any left. Sometimes empty shells wash up on beaches, especially after typhoons. They might not be in perfect shape, but you will be a better person for not killing these pretty little things.
When I was a teenager growing up in Hong Kong I was fascinated with marine life and naturally went looking for it everywhere I could in Hong Kong. I went snorkeling, beach coming, volunteered as a dolphin-spotter and scoured bookshops and libraries for any information on HK’s marine life. The state of the coastal waters around HK at the time were terrible and I decided that one way to help would be to educate anyone interested in marine life in HK so that people would treasure it more and look after it more carefully. So in 1994 I started a web page called “the Hong Kong Marine Life” page to do just that. The page – all hand written HTML – has long since dissapeared, of course.
I actually went on to become a marine biologist and wrote my PhD thesis on microscopic Antarctic deep-sea creatures and then worked in the Natural History Museum in London for a couple of years. But as great as marine biology is, it is unfortunately hard to earn a living in that line of work. So in the end I had to take a normal job (which is still fun), but I still have a passion for marine biology and oceanography and I am still concerned about the impact we as human beings have on the ocean ecosystem.
Being back in Hong Kong though, I have noticed important changes – some for the better, some for the worse. So I have decided to offer my knowledge, my passion for HK marine life and an inexplicable thirst for finding and compiling information into more useable form, to restart the HK marine life page as a blog. That – by the way – also is all I have time for these days!
So what I am going to do with this blog is I am going to try to capture some thoughts, answer some questions and give some interesting facts and figures on all things do to with the wonderful world under the sea in Hong Kong.
I hope you enjoy this blog and that it teaches you something new or interesting. Feel free to request specific posts or ask any questions, I will be happy to help.