Four new Reef Fish Species for Hong Kong

A study by Allen W.L. Lo and Stanley K.H. Shea published recently in Msrine Biodiversity Records, has found 4 species of reef fish not previously known from Hong Kong waters. They also conclude that these 4 species are not introduced. So here is a welcome list of Hong Kong’s newest residents:

Ambyleleottis japonica

A Goby that grows to only 8.5 cm length and lives near the bottom and about which very little is known.

picture by J.E. Randall via Fishbase

 


Halichoeres hartzfeldii – the Goldstripe Wrasse

A reef living wrasse of the Western Pacific that grows up to 18cm in length.

picture by J.E. Randall via Fishbase



C

anthigaster papua – the Papuan Toby

A pufferfish species from the West Pacific that grows to 10cm.

picture by J. Bednarzik via Fishbase

 


Parapriacanthus sp. – a species of Sweeper

The authors of the paper did not identify it to species so this is just a placeholder.

Parapriacanthus ransonnetti via WikiCommons
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Extinct in Hong Kong – the Maxima Clam (Tridacna maxima)

The giant clam Tridacna gigas which can grow to 120 in width and 200 kg in weight is one of a group of clams called giant clams – the Tridacnids. Although T. gigas is the biggest of them, there are others which are still pretty huge by clam standards. One of these giant clam species, the Maxima clam Tridacna maxima, used to occur in Hong Kong. It grows to about 40 cm width, though typically is only around 20 cm in width. But consult the IUCN records for this clam species and you will see that although it occurs throughout the tropical and sub-topical waters of the Indian and western Pacific Oceans, the entry for Hong Kong sadly reads ‘regionally extinct’. When did that happen? Why did they vanish? These are the questions I wanted to find answers to.

When did it go ‘regionally extinct’?

The first entry I could find for the Maxima clam being regionally extinct in Hong Kong is 1983. Unfortunately that’s about all I could find. But at it has been gone from Hong Kong since at least 1983. Unless of course it has returned….its a slow-growing animal but has a very wide dispersal through free-floating larvae that live in the plankton – that’s why it occurs over such a wide geographical area spanning nearly a quarter of the planet! So theoretically, if conditions are right (see more below) and larvae are swept over Hong Kong or are purposely introduced by humans, the Maxima clam could reestablish itself in Hong Kong.  So the next question is why did it go extinct in Hong Kong in the first place?

a Maxima clam tucked into some hard coral (via WikiCommons)
a Maxima clam tucked into some hard coral (via WikiCommons)
What happened to the Maxima clam in Hong Kong?

Apart from the fact that the Maxima clam lived on coral reefs in Hong Kong waters, I can not find any more details of how big the population was, which exact areas in inhabited (obviously coral reefs, so that narrows it to Eastern and Southern Hong Kong waters) or whether it was harvested locally. It is however clear that Hong Kong used to be a big regional market for giant clam species in Asia. Giant clams were and still are a delicacy in Asia (mostly the meat big abductor muscle) and the shell was used for decoration (though not extensively). Even the UN Food and Agriculture Organization has no useful fisheries statistics for Tridacnids. So there is no information on how many – if any – were harvested from Hong Kong waters before they disappeared.  The maxima clam like all clams is a filter feeder which suck in water, filters out and swallows edible particles and then ejects the water out again. As such it is quite vulnerable to toxic substances in the water. In addition, it harbors symbiotic microscopic algae called zooxanthellae (zoo-oh-zan-the-lay) in its tissue. These absorb the clams waste  products like CO2 and photosynthesize turning them into sugars in the presence of sunlight and giving off oxygen for the clam.

When open, the bright blue, green or brown mantle of the clam is exposed and obscures the edges of the shell which have prominent distinctive furrows. The attractive colours of the mantle are the result of pigment cells, with a crystalline structure inside. These are thought to protect the clam from the effects of intense sunlight, or to bundle light to enhance photosynthesis of the zooxanthellae.

 

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Maxima clams – one open showing the brightly colored mantle, the other closed and only identified by the zig-zag pattern of the shell valves. (via WikiCommons)

This is essentially what corals do, too, which is why they share the same habitat – coral reefs. And like most reef corals the maxima clam also gets most of its nutrients from its zooxanthellae . Coral reefs suffer enormous damage from smothering by sediment that washes into the sea from rivers and rainfall and from clouding of the water and smothering by excessive algal blooms. Both of these were and still are to some extent big problems for Hong Kong waters, whereas in the past this was not the case. Algal blooms and sediment runoff increased a lot as a result of the increase in human population in Hong Kong and as a result of rapid industrialization and the associated water pollution. This combined with harvesting seems to be the most likely reason for the disappearance of the Maxima clam from Hong Kong waters before 1983.

Will there ever be giant clams in Hong Kong again?

I hope so. Like I said earlier, if conditions are right, any of the wide-ranging planktonic larvae of the clam that stray into Hong Kong waters could settle and grow to adulthood. Failing that humans could also try to establish them by attaching cultured juveniles to appropriate spots on reefs – but this is more complicated and costly, although Singapore has attempted this with initial success using another giant clam species Tridacna squamosa. But the main criteria is suitable conditions for a population to establish and grow – in other words we need clean seas again. Hong Kong has improved a lot on this front up until very recently, when the increased coastal development in southern China started to create a lot of water pollution which somewhat diminishes the results. There is still a long way to go. But I would say that divers should keep an eye out. In fact, the ReefCheck 2015 recorder forms even have a section for giant clams (Tridacna sp.), so its not just me that is hopeful! You never know. you could be diving some coral reef in Sai Kung, Tung Ping Chau, Hoi Ha Wan or the Ninepin Islands and come across a maxima clam. It might be an old dead one stuck in a reef with just the wavy outline of the two shell valves (probably) or it could have the fat, bright blue or green mantle of a live clam – in which case 1) hooray for Hong Kong and 2) please report your finding to the AFCD and Reef Check!

South China Sea Reef Destroyers Want Your Money

According to a recent FT.com article the company responsible for most of the destruction of coral reefs and reef habitat in the disputed Spratly Islands is listed on the Hong Kong stock exchange and is planning an overseas listing.

China Communications Construction Company (HK:1800), a large state-owned infrastructure group, announced in March that it was integrating its three dredging assets into a new company, CCCC Dredging, which it would eventually list overseas. That entity was set up in Shanghai’s Free Trade Zone on Wednesday.

China’s dredging programme has created about half a dozen islands in the South China Sea with deepwater harbours and at least one airstrip.

In the past 18 months, according to the US defence secretary, at least 2,000 acres of land have been reclaimed — more than has been done in 60 years by other claimants to the territory, including Vietnam, Malaysia and the Philippines.

Satellite images analysed by IHS Jane’s, the defence consultancy, show that Tianjin Dredging Company, one of CCCC Dredging’s three subsidiaries, operates most of the giant barges that have been digging sand from the seabed and piling it on remote coral atolls with names such as Mischief Reef, Suba Reef and Fiery Cross.

The flotation plans are curious for secretive Tianjin. A listing would require greater transparency and focus more attention on its activities.

In March CCCC said in a filing to the Hong Kong Stock Exchange, where it has been listed since 2006, that it “intends to seek listing of CCCC Dredging overseas at an appropriate market timing”.

Hongkongers and potential overseas investors should be aware that CCCC is not an ethical investment. 

Source: FT,com June 11th, 2015

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.

Pristine Coral Reefs Destroyed by ‘Great Wall of Sand’

China is creating a ‘great wall of sand’ in the South China Sea, according to the Daily Mail.

The latest huge land mass is four square kilometres in size and was created by dumping sand on live coral reefs, damaging local ecosystems.

But this is just one of several artificial islands China has been creating in the region – and the exact purpose of them is unknown.  

 

 

The large expanses of sand and concrete – the latest being Johnson Reef – are being built among the Spratly Islands in the South China Sea.

China is creating the area by using dredging vessels to dig up sediment from the sea, and then dumping it on subermeged coral reefs to make islands.

China has supposedly been carrying out the land reclamation in order to build airstrips and other structures in the region.

  

Five islands in total have been built in this way, and two more are in development. 

Richard Dodge of the Nova Southeastern University Oceanographic Center, said: ‘The activities described would appear to clearly both be greatly exceeding corals and coral reefs’ ability to cope and survive the excess sediments and turbidity.’

He said that as the reefs were being covered by cement and landfill, this constituted ‘outright destruction’ of the buried coral reefs and associated habitats. 

‘Coral reefs are extremely globally and locally valuable both for the biodiversity and ecosystem they create but also for the tremendous services they provide in terms of food supply, cultural heritage, erosion prevention, recreation, tourism, and habitat for myriad other organisms,’ he continued.

‘Coral reefs worldwide are under extreme threat from changing climate and from local sources of land based pollution, over fishing, and coastal construction.

‘The activities described would appear to represent an additional and severe threat to coral reef ecosystem health and sustainability.’

  

Robert Nicholls, a Professor of Coastal Engineering at the University of Southampton, added: ‘It is clearly destroying [coral reefs] at the local scale of the land claim and the environment.

‘In the bigger scheme of things it is harder to be precise as these are small areas in a large area of reef.’

China is creating land by pumping sand on to live coral reefs – some of them submerged – and paving over them with concrete. It has now created over 4 square kilometers of artificial landmass.

The region is known for its beautiful natural islands, but ‘in sharp contrast, these actions are are creating a great wall of sand with dredges and bulldozers over the course of months.

Dynamite Fishing in Daya Bay

Fishermen in Daya Bay – home to Hong Kong’s closest nuclear power plant – face an official crackdown on their use of home-made bombs to blast fish out of the water.

So-called ‘blast fishing’ is outlawed in many countries because of the destructive and unpredictable effect it can have on the marine ecosystems that support fish stocks.

But the practise is nonetheless thriving in Daya Bay, less than 100km northeast of Hong Kong. Visitors there can even pay to go out with the fishermen and throw a few bombs in the water themselves.

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The pictures below were published by the Daily Mail in an area described by travel guides as ‘an unpolluted, quiet paradise for sea-lovers’ and show fishermen hurling explosives into the water to stun or kill fish.

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Their target are yellow croakers (Larimichthys polyactis) that they head out to catch every November. But the explosions also kill other sea life in the area and severely damage the underlying habitat.

Underwater shockwaves from the explosions stun fish and rupture their swim bladders – the tiny gas-filled organs that help fish to control their buoyancy. The rupturing causes an abrupt loss of buoyancy, so while a small number of fish float to the surface, many more sink to the sea floor, where they join any other marine organisms indiscriminately killed by the blasts.

But this irresponsible practise has now apparently become a tourist attraction. An angler who unwittingly signed up to a trip in Dayawan Bay, said:

We saw an advert promising ‘fishing action. We’d been out for about 30 minutes when the men told us they were going to feed the fishes. They were laughing and stuffing the bottles with powder and what looked like stones. They then threw them overboard and just seconds later there was a huge series of explosions.
And then all these dead fish appeared floating on the surface which the fishermen hauled in with nets. I was absolutely disgusted and shocked beyond belief.

A spokesman for the Chinese Fishery Bureau said: ‘These fishermen make most of their money from taking tourists out to watch them at work. We are attempting to crack down on it though.’

Source: MailOnline, 1/12/2014

Southeast Asian Territorial Disputes Are Literally Killing Off Coral Reefs

This week Bloomberg’s Adam Minter wrote a great article on the plight of the South China Seas coral reefs and their large scale destruction in the name of territorial Claims by China, Taiwan, Vietnam and the Philippines.
I have written about this previously (here and here), and I am happy that a professional journalist – for a widely-read news publisher no less – has devoted some time and effort to bringing media coverage to this issue.
Below are some new and interesting insights from extracts of the article ( BloombergView “Victims Under The South China Sea” 26/11/2014).

[…] in the South China Sea, where nations seeking to enforce their territorial claims have not always spent much time worrying about the environmentally and economically valuable reefs under the waves. How valuable? A 2011 report to the UN General Assembly on coral reefs noted that seafaring Asian nations count between 100,000 and “more than” 1 million coral reef fishers among them.

One might think that governments, pressed by those fishermen, would be striving to preserve fragile reef systems. But just the opposite has happened. According to a 2013 study by Australian and Chinese scientists, the South China Sea’s atolls and archipelagos have seen their coral cover decline to 20 percent from averages of 60 percent or more just 10 to 15 years ago.

The large-scale reclamation of reefs for military purposes is just the start of the damage. What happens after can oftentimes be much worse. “If 1,000 soldiers are stationed at any one time in a place, they typically cut down vegetation and cause runoff, generate sewage,” says Terry Hughes, a marine biologist and director of the Queensland-based Australian Research Council Centre of Excellence for Coral Reef Studies.

Draining into the sea, runoff is deadly for coral: In coastal China, where cities also tend to discharge effluent into the ocean, 80 percent of all coral has died off. In 1980, the amount of coral cover near a large Taiwanese military outpost in the disputed Spratly Islands was 60 to 70 percent. By 2007 it had declined to 17 percent, according to the 2013 study, which Hughes led.

That sort of damage is likely to grow more common: In October, Taiwan’s top intelligence official revealed that China has seven ongoing South China Sea construction projects. When complete, they’ll join at least 20 additional reclamations owned by four other South China Sea claimants.

Even worse than the direct damage from construction projects is the political deadlock caused by various territorial disputes. The biggest threat to coral is the large-scale use of cyanide and explosives by the region’s fishermen. As Hughes’s 2013 study pointed out, at just one atoll, the number of fishing boats using cyanide and dynamite to kill fish increased nearly eight-fold between 1996 and 2001. By 2001, “virtually everything harvestable (e.g., fish, mollusks, crustaceans, echinoderms) had been stripped from the atoll.”

Rogue fishermen are the immediate culprits, but a lack of governance and oversight allows them to continue their depredations. While that’s no secret to any of the six South China Sea claimants, they’re unlikely to agree on where or how to protect coral if they can’t agree on boundaries first. Instead individual countries have tried to impose fishing limits unilaterally, which no one else follows. “When it comes time for governance, everyone puts their hand up and that means no one,” says Hughes.

Nonetheless, Hughes remains optimistic, if only because corals can regenerate when protected and given time. (Decades are needed.) He suggests that in the absence of a broader agreement on regulating the South China Sea, scientists from the region might begin the discussion on how to protect reefs. Translating any recommendations into action won’t be easy. But it’s probably the best option for ensuring that soldiers and tourists won’t be the only living creatures left to enjoy the seas.

(Featured image shows structures built on top of Johnson Reef)