| Port Shelter | |
| Other Name: | Inner Port Shelter, Outer Port Shelter |
| Image Bathymetry: | File:Volonteri's map of the Xin'an County, 1866 (enlarged3).png |
| Caption Bathymetry: | Map of Xin'an County of 1866 (enlarged), showing the Port Shelter and the town Sai Kung |
| Location: | Sai Kung District, the New Territories, Hong Kong |
| Coordinates: | 22.3417°N 114.289°W |
| Type: | Bay / harbour |
| Designation: | water [pollution] control zone |
| Salinity: | 32.7 (measured in 2002–03; 3 sample points) |
| Pushpin Map: | Hong Kong |
| Pushpin Map Caption: | Map of Hong Kong and the approximate location of the centre of Port Shelter |
Port Shelter, known in Cantonese as Ngau Mei Hoi, is a harbour south of Sai Kung Peninsula in Hong Kong. The water body connects to Inner Port Shelter (known in Cantonese as Sai Kung Hoi;), as well as Hebe Haven, Rocky Harbour and other water body. Outer Port Shelter, is situated at the mouth of the harbour.
The boundary of Port Shelter has different definition according to different sources. Publication of the U.S. Hydrographic Office, had stated the western shores of Keui Island (now known as Kau Sai Chau[1]) and Jin Island, as well as eastern and north-east shores of the mainland area (now HKUST, Tseung Kwan O New Town and Clear Water Bay Peninsula), were the boundaries of Port Shelter.[2] The Hydrographic Office also stated the entrance of the harbour lies between Lung Ha Wan (; located in Clear Water Bay Peninsula) and [a] Peaked Rock, with a width of about .[2] Earlier publication of the Office, had stated the peaked rock is located south of Jin Island. The rock was above water at that time.[3] Inner Port Shelter is located near the head of Port Shelter, while Hebe Haven was classified as an inlet in the western shore of Port Shelter.[2] The entrance of Inner Port Shelter lies between Yingam Tow and a line of rocks that extended from Kiau To, an islet (now spells as Kiu Tau;).[2] The islet itself is connected to Sharp Island (Kiu Tsui Chau;) by a bank.[2] The bank, or known as a sand levee or a tombolo, is part of the Hong Kong UNESCO Global Geopark.[4]
While The Hydrographic Office's 1943 publication did not have the definition of Outer Port Shelter, H.K.'s Agriculture, Fisheries and Conservation Department had deployed artificial reef to the Outer Port Shelter in the 2000s. They defined the area by coordinates instead.[5] Roughly, it is a triangular area between Steep Island, Basalt Island and the southern shore of Jin Island (known as Tiu Chung Chau in the publication).[5]
Environmental Protection Department, partnered with local universities, also conducted water quality and phytoplankton research in the Port Shelter. In their research, they used a border definition of the area, which their Port Shelter includes Port Shelter proper, Inner and Outer Port Shelter as well as Hebe Haven, and is a bay that "bordered on its northernside by the Sai Kung Peninsula and on its west and southwestern sides by the Clear Water Bay Peninsula". They also found out that, some data point of their research, are obviously influenced by surface runoff and pollution loading from the surrounding catchment area.[6]
These islands are considered within the boundary of the water body of the Port Shelter proper:[7] The three largest islands were Kau Sai Chau, Jin Island and Sharp Island respectively.[8]
Note: the book Southern District Officer Reports: Islands and Villages in Rural Hong Kong, 1910–60 also listed High Island, Town Island and Ninepin Group in their chapter "The Islands of Port Shelter".[9] But the first two are located in Rocky Harbour, and the last one is outside the mouth of Outer Port Shelter.
These islands are considered within the boundary of the water body of Inner Port Shelter:[7]
The greater Port Shelter area receives discharge from Ho Chung River, Tai Chung Hau Stream, and Sha Kok Mei Stream,[10] as well as man-made storm outfalls and a submarine outfall from the Sai Kung Sewage Treatment Works.[11]
According to measurements by a research, the average salinity of their three sampling stations was 32.7. All stations are located inside Port Shelter. The measurements, conducted from 4 October 2012 to 15 April 2013, also found that the average water temperature was 19.1 °C (with a range from 15.8 °C to 27.8 °C), as well as pH (acidity) of 8.08, with range from 7.62 to 8.35.[12] They also recorded the vertical profile for some of their measurements.[12]
Another research, recorded and estimated the tidal flushing time of the greater Port Shelter area which their tidal stations were deployed in the Port Shelter proper, as well as in Rocky Harbour, Hebe Haven, Inner Port Shelter and Outer Port Shelter. Such as a station at Leung Shuen Wan (; or known as High Island) and in Po Toi O.[11] They concluded that in the inner Port Shelter, the flushing time is the longest among the fish culture zones of Hong Kong, which is 40 days in the dry season.[11] While Po Toi O is located at the mouth of Port Shelter, its hydrodynamics is mainly affected by the open ocean, thus the flushing time was just 5.3 days in dry season in the computer estimation.[11]
A research conducted in 2006, had recorded a total of 106 fish species in Port Shelter in their preliminary report, including rare species Cephalopholis urodeta, Bodianus axillaris and Echidna nebulosa.[13]
In a 1863 book, stated Port Shelter and Rocky Harbour are the two main components of a deep bay.[14] At that time the water body was still part of the Qing Empire, under the Xin'an County.
Port Shelter was also mentioned in a report to the UK government in 1898 by James Stewart Lockhart, shortly after the signing of the Convention for the Extension of Hong Kong Territory. It stated the harbour is a deep water port that suitable for ships in any size.[15] The Convention ceded Port Shelter and other areas that collectively known as the New Territories and New Kowloon, to the British Empire, as an extension of the colony of Hong Kong.
In the past, villagers from the six villages of Pak Tam Chung, would collect coral from Port Shelter to make lime.[16] Nowadays, fishermen still catch Sea urchin in the Port Shelter.[17]
In 1950, (some source said 1936) the harbour and some islands were part of the Port Shelter Firing Range, an outdoor firing range for the British military that stationing on the colony.[18] [19] Most of the range ceased to be used in the 1970s.[20] The government also relocated the residents of Kau Sai Chau, an island in the firing range to the land area of Hebe Haven (known as Pak Sha Wan in the publication) in the 1950.[19] The permanent housing was completed in 1954.[21]
In 2011, a mortar shell was discovered on Shelter Island, which was formerly part of the firing range.[22]
Despite there is no legal definition of the boundary of the water body, a related concept Port Shelter Water Control Zone had a legally defined boundary. It was regulated by the Water Pollution Control Ordinance (Chapter 358 of the Law of Hong Kong) as well as "Water Pollution Control (Port Shelter Water Control Zone) Order" (Chapter 358M) and other regulations. The water control zone covers not only the Port Shelter and Inner Port Shelter proper, but also Hebe Haven, Sham Tuk Mun, Tsam Chuk Wan, Rocky Harbour and many other surrounding water body.[23]
In 2018, Typhoon Mangkhut damaged the Sai Kung Sewage Treatment Works, which just bordering the water control zone. After emergency repairs, the government did not find the water quality of the water control zone had become worse.[24]
Another related and overlapping concept, the proposed Outer Port Shelter Marine Park,[25] was scrapped in 2014.[26] The proposed size of the marine park was .[25]
In 2018, World Wide Fund for Nature proposed to establish Port Shelter Marine Protected Area.[27] [28] They proposed to turn at least 30% area of Port Shelter to be a no-take zone. Their definition of Port Shelter was excluding Hebe Haven, Outer Port Shelter and part of Inner Port Shelter, with a size of .[29]
Port Shelter, Inner Port Shelter, along with Rocky Harbours were also included in a proposed fisheries protection area in the 2000s, while Outer Port Shelter was listed as a no-take zone.[30]
In the Schedule 2 of the Merchant Shipping (Certification and Licensing) Regulation (Chapter 548D of H.K. Law), they defined Port Shelter, in Specified Sheltered Waters context. For the purpose of that regulation, they defined Port Shelter Area as:[31]
The specified sheltered water that defined from above coordinates and natural boundaries, actually covers the Inner Port Shelter and Hebe Haven but only part of Port Shelter, that defined by the publication of the U.S. Hydrographic Office, which draw the southern boundaries from Lung Ha Wan to a peaked rock south of Jin Island.
That regulation also defined "Port Shelter and Rocky Harbour Area" that cover all of the Port Shelter (and some part of Outer Port Shelter by some definitions) and Rocky Harbour:[31]