Death on the high seas: Coral destruction in Hoi Ha triggered by TPB

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The corals in Hoi Ha Wan Marine Parkare under attack. Over the past two months around a quarter of the reef areas have been wiped out: Almost half a square kilometre of Grade-A coral area, over 70 years old,  is no more.  If this continues then all the corals in the Marine Park could be gone before the year’s end. (Photo provided by Professional Commons)

Written by Stanley Ng Wing-fai (吳永輝), Chair, The Professional Commons and Robin Bradbeer, Secretary, The Professional Commons.


Hoi Ha’s Grade A protected coral are disappearing at an alarming rate – and bad decisions are to blame.

The representations made during the consultations on the draft Outline Zoning Plan for Hoi Ha, finally gazetted by the Town Planning Board (TBP) in February 2015, produced some solid science that strongly suggested that the Pak Sha O River Valley (PSORV) should be substantially protected from any development. The PSORV encompasses three enclaves – Hoi Ha, Pak Sha O and Nam Shan Tung. They are part of an ecologically sensitive area that encloses the watershed of the whole valley.

Professional Commons submitted two representations; one on the original consultation and one on the draft recommendation. They proposed allowing an area, relatively ecologically insensitive to the south of the village, be zoned for any proven need for village expansion and for the rest of the enclave to be zoned Country Park. The village expansion area should be zoned, along with the existing village, as a Comprehensive Development Area, basically removing the exempt status from any small houses. We suggested this as a model for all the Country Park enclaves.


Sensitive areas left unprotected

Unfortunately this proposal was not accepted by the TPB and parts of the ecologically sensitive valley area, mainly the flood plain of the river, were zoned Green Belt and Village zone. The beach front area was also zoned Coastal Protection Area. The report from the Professional Commons was the most detailed and comprehensive document on the area. At the public consultation on the draft OZP in 2014 we opined that the lack of independent environmental impact assessment (EIA) for any of the enclaves being zoned meant that the zoning proposals were just lines on a map and lacked any logical or scientific basis.

The PSORV is a wildlife corridor that terminates at the river estuary at Hoi Ha. There are many endangered animals using this area including the critically endangered Chinese Pangolin. Interfering with this area has already disrupted the ecology of the corridor.

The recent reintroduction of farming after 25 years absence at Pak Sha O has resulted in more harmful nutrients leaking into the river estuary. The draft OZP for Pak Sha O, now under representations, not only encourages more agriculture but also massively increases the amount of land available to developers to build up to 49 houses. As most of this zoning for Village and Green Belt will occur on the wetlands feeding the Marine Park, we expect the level of nutrients and other pollutants to increase significantly.


A plague of rats and snakes

The clearing, last June/July, of parts of Hoi Ha zoned as GB and V zones, has shifted a large population of rats into the village. Snakes have followed them in. Residents are, unsurprisingly, complaining. The Government is yet to respond to this problem in an adequate way, other than cutting down overgrown tress and undergrowth in the upper village.



The Professional Commons submissions also identified impacts on the existing ecology of the Hoi Ha Wan Marine Park. The sewage overflow from current inadequate facilities for the houses along the foreshore, and future New Territories Exempted Houses (most of which will be luxurious small houses) allows human pollution to enter the Marine Park. The establishment of a Coastal Protection Area has allowed this issue to continue unabated, as it allows continuing pollution from existing sources. We also predicted that the building of more houses in the ecologically sensitive areas of Hoi Ha and Pak Sha O would also spell doom for the corals and other creatures that are currently protected.

Had the assignment of the Coastal Protection Zone been Country Park, or even Conservation Area, as we proposed, then those responsible would have had to increase the volume of their existing septic tanks to cater for the extra water these systems have to process, after these houses were connected to mains water supply. In the past the village water supply was limited to about 1m3 per day. With city water now connected to the village, the water supply is unlimited, causing the small septic tank systems that originally had to cater for 1m3 per day to overflow from the extra grey water use from dishwashers, washing machines and more showering, and even 1.5m3 jacuzzis.

This human pollution caused a change in the overall ecology of the bay in 2006 when no Sea Hares, for example, were recorded on the beach during their annual breeding migration. This indicated a change in the algae in the Marine Park. This was a direct result of the nutrient levels in the bay changing. In 2012 a comprehensive E.coli count programme was set up along the beach to gather information about the extent of this problem. The river was also monitored at the Hoi Ha end for fertilizer after farming was reintroduced at Pak Sha O the same year. The overall trend was a slow increase over time with both of these parameters.


Degradation predicted…and delivered

Too many nutrients entering the sea disrupts the ecological balance of bays and inlets. The Hong Kong University (HKU) agreed there was a problem with a totally different set of data collected independently of the Professional Commons, which was also presented at the public consultation on the draft OZP. Both the HKU and the Professional Commons clearly stated that this situation would degrade the Marine Park. Indeed, it has.

On 18th January, dives conducted at the coral area off Moon Island and the corresponding coral location opposite, off Flat Island, reported the sad situation that areas that once had ~50% coral cover with 35 different species were totally bio eroded back to boulders. Even the coral skeleton was gone. This bio erosion was the direct result of sea urchins grazing on the corals, after having been attracted by the algae growing because of an increase of nutrient levels. Almost half a square kilometre of Grade-A coral area located in a Marine Park was gone.

To make matters worse, the massive population of urchins responsible for this were moving further into the Marine Park towards the other coral areas. The population was measured to be over double the maximum population ever measured in the area, with an incidence 60 times the average over the previous 20 years. The age of the corals in this area was over 70 years old, so this is not a regular occurrence. The area had previously been dived only two months before and nothing untoward was seen at that time. Contributing to this eco-disaster was the fact that the natural predators of the urchins, crabs, had been fished to extinction in the area adjacent to Tolo Harbour, at the extreme edge of the Marine Park closest to Moon Island and Flat Island. This allows unimpeded access for the urchins.


Government priorities all wrong

Unless the Hong Kong Government gets serious about protecting the special areas we have, as well as the surrounding region that impact those areas, Hong Kong will become a barren wilderness without biodiversity or a healthy natural ecosystem. At this time there needs to be a shift away from any form of development inside the Country Park boundaries. Any permitted development needs to follow a proper EIA that details the impacts to surrounding sensitive receivers and moves proposed building to areas that are not sensitive themselves or will impact sensitive areas.

For us to lose so much coral area in the short time of two months is totally unacceptable. It shows that planning decisions can have a huge impact on the surrounding ecology. Although it is the Town Planning Board that has effectively caused these problems and it is the unfortunate Agriculture, Fisheries and Conservation Department that has to clear up the mess and will probably get the blame.

The Professional Commons urges that the relevant government departments, including the Planning Department, and the Agriculture, Fisheries and Conservation Department, be responsible in comprehensively monitoring and conserving the whole Pak Sha O River Valley and the and Hoi Ha area.