Location of HongKong• northern subtropics, betweenLat. 22°08’-22°35’ N,Long.113°49’- 114° 31’E• northern rimof South ChinaSea–hillyandrugged terrain stretching out tobroad,shallow continental shelf
• Cool dry winter – Northeast monsoon(Taiwan current &Kuroshio>15oC)Hot wet summer – Southeast monsoon(Hainan current + rain)
Location of HongKongHainan Current
Taiwan
Current
NE Monsoon
SE Monsoon
Hong
Kong
Kuro Shio
Location of HongKongESTUARINE TRANSITION OCEANIC
Location of HongKong• eastern side of Pearl River Delta• gradient of salinity fromeast towest
east – oceanic
middle – transition
west – estaurine
• Summer monsoonal rain freshwateroutflowhalocline &bottomintrusionofhypoxicoceanic water
Current flowpatterninHongKong
Geology of HongKong
Geology of HongKong• Complex – volanic (50%), granitic(35%),sedimentary (15%) metamorphic(tiny)• On broad shallowcontinental shelf• Last ice age – rise of sea level, drowningriver basins and isolating former mountainpeaks as offshore islands (>200)
Bathymetry of Hong Kong MarineWaters
Environmental
Characteristics
• 1,106 km2 land 1,649 km2 sea
• 733 km coastline 234 islands
• Tidal range 1-2 m Tidal current 0.5- 1.5knots
SoutheasternExposedrockyshoreline–Steep, exposedgraniticshores withexposedsandybeaches inbetweenSouthwestern
Moderately exposed + low
salinity – semi-protected
sandy and muddy shores
NortheasternEnclosedembayment–Protectedsandflats&slopingrockbeachesNorthwestern
Sheltered + river discharge – Mudflats & mangroves
Marine Habitat DiversityinHongKong
Marine Flora andFauna• Unique geographic location,
• Subtropical climate (border between temperate andtropicalzones)
• Wide range of habitats – rocky, sandy &muddyshores, coralreefs, seagrass beds and mangroves
• All the above together contribute to high diversityof marinelife.
Finless porpoise
Neophocaena phocaenoides
Finless porpoise
Neophocaena phocaenoides
Chinese white dolphin
Sousa chinensis
Marine mammals
• Chinese white dolphin
Estimated 1300 – 1500 dolphins in East Pearl River &HongKongwaters
Finless porpoise
Estimated population around south of Hon Kong is 217individuals
Sea Turtles
• 7 sea turtles species in the world, 5recordedinHong Kong (tropical & subtropical) –all endangeredLeatherback OliveRidleyGreen Turtle
Loggerhead Hawksbill
Sea Turtles
• Only the Green Turtle breeds inHongKongGreen turtle
Marine Fishes
– Hong Kong’s territorial waters (1,650 km2) is only0.05%oftheSouth China Sea (~3.4 million km2), yet it has around30%ofthemarine fish species recorded in the South China Sea. – Over 1000 species (150 commercial, 300+reef fish)
Red grouper juvenile
Blue reef chromis
RedempororjuvenileCardinalfishYellow finned seabream Trigger fish
– Yellow seahorse (Hippocampus kuda), moderatelyabundant in the coral &nearby easternwaters(↓7m)- Three-spot seahorse (Hippocampus trimaculatus)- Great seahorse (Hippocampus kelloggi)
Seahorse
Seahorses
• Information lacking (54 species)
• HK Reef check data : 3 species
OrientalseaslugBenthic Fauna• Majority of HK subtidal seabed is soft, a mixtureof sand&mud.• Composition of the sediment varies &determines thetypeof• 603 marine benthic animal species. Polychaete annelids(47%),crustaceans (14- 18%) and bivalves (11%) are most abundant,totalover 70% of the total recorded species. (2001-2003study)SpottedboxcrabBathygobiusfuscusbottom-dwelling organisms. • Important in nutrient recycling
BranchiostomabelcheriAmphioxus
Tube worm
ale worm
Painted pebble
crab
Banded coral
shrimp
Babylonia areolata
Conus textile
Intidal BenthicFauna• The intertidal zone – a harsh environment withincessant alternationsbetween living above and below seawater, intertidal speciesexhibitvarious adaptive physiological and behavioral traits. • Community depends on the substrate and exposureof theshore- Rocky shores : barnacles, chiton, mussels, oysters, whelks,searoach, crabs, sea urchins etc. Tetraclitajaponica
Amphibalanus
amphitrite
Acanthopleurajaponica
BrachidontesvariabilisSalmacisspheriodesSaccostrea
cucullata
Capitulum
mitella
Ligia exotica
Thias clavigera
Grapsus sp
Sesamid
crab
Clithon
Fiddler crabBarnacles
Sea urchin ClamTubewormIntidal Benthic Fauna- Sandy shores (surface : horseshoe crabs, crabs, seasnails,Horseshoe crab Sesamid crab Hermit crab
Siphon of burrowing
clam
Sipunculid
worm
Sea cucumberNassarius sp. Pistol shrimpNatica sp. Clithon sp. Starfishclam
wormGreen crab
Intidal BenthicFauna- muddy shores : mudskipper,crabs,razor clams, fanmussel, tubedwelling worms, TerebellidFan mussel
TerebellidwormtubeopeniTerebraliasulcata
Fiddler
crab
Mud skipper
razor clam
Interaction of nutrients and other gasesbetween the benthos and other organisms inthewatercolumn
Components of a typical soft bottommacrobenthiccommunityThe conditions of benthic organisms, are sessileandtherefore,indicative of time-integrated effects of various kindsofenvironmental stress. Mudskipper
Changes of macrobenthic faunal compositionalong an organic pollution gradient inthesediment
Characteristics of the MarineBenthicCommunities inHongKong• Western – estaurine muddyspecies• Victoria Harbour – species adaptedtoeutrophic environment
• Northeastern – relatively lowecologicalimportance
• Eastern and southern – homogeneousincomposition and diversity, higherecologicalimportance
Important Benthic Fauna- Oysters• 12 species described
– Crassostrea hongkongensis &C. ariakensisculturedin Deep Bay
– Saccostrea cucullata dominates eulittoral zoneofsheltered rocky shores around HK.
Important Benthic Fauna–Pearl OysterPearl oyster (Pinctada margaritifera)
• Pearl oysters beds in sheltered coastal waterse.g.Tolo• Pearl Culture (Control) Ordinance repealedin1995• Recent cultured in fish culture zones.
Carcinoscorpius rotundicauda(√)Tachypleustridentatus (√)
Tachypleus gigas
Of the 4 species of horseshoe crabs intheworld,3recorded in Hong Kong, but only 2 livinginHKwatersImportant Benthic Fauna – HorseshoeCrabLimulus
polyphemus
Local distribution ofjuvenilehorseshoecrabs
Sargassum dominant in areas exposed to
strong waves. • grow rapidly from Oct – May &disappear (die-back) completely fromJun – Sept. • grow up to 2 – 3 m in length
• important nursery habitats for
juvenile fish and invertebrates e.g. molluscs, echinoderms. provides
shelter and protection
• In Tung Ping Chau, Yan Chau Tong,
Hoi Ha Wan Marine Parks
Benthic Flora
264 species of marine macrobenthic algae (seaweeds) recordedinHong Kong. 82 brown algae, 141 red algae and 41greenalgae.Occurrence vary seasonally mostly in winter or earlyspring.
Seaweeds
Porphyra (Phycocalidia)
• A red algae. Blades brown to
purplish red in colour. • Grows in lower intertidal to
upper subtidal rocky shore
exposed to stronger waves fromDecember to March in eastern
waters. Harvested for food and sold locally byfishermeninPo Toi. historically regarded as a Chinesedelicacyin the coastal region.
Ulvafasciata
Ulva lectuca Cladophora
SeaweedsEnteromorpha intestinalis
Special Coastal &MarineCommunities• Coral communities
• Seagrass communities
• Mangrove communities
• Brackish marsh, intertidal mudflat
G pos.p. r
rapoononi
Coral CommunitiesStony/hard corals
– 84 species from 28 genera
hermatypic with zooxanthellae
Favites sp
Platygyrasp.
Coral CommunitiesOctocoral – no stony skeleton, supported by sclerites (67spp)Soft coral (29 spp),
Gorgonians (26spp), sea pens, sea fans (12 spp) –axial hornyskeletonBlack coral – tree like, black/dark brown chitin skeleton, (8spp)community
Common Soft coral
Soft coral
Sea penBlue coral
Black coral at TungPingChauGorgonian at Port Island
Common soft coral
mmon
rgonian
Distribution of Coral inHongKongWaters• Usually directly attach onto bouldersandbedrockto form scattered fringing coral communitiesalongthe coast
• Isolated coral colonies mainlyinthesub-tidalzoneof the rocky shores around outlyingislands• richest coral communities prevail inthenortheastern waters, free fromtheinfluenceofPearl River
• scattered stony coral communitieshavealsobeenrecorded in the southwesternwaterse.g. SokoIslands
SeagrassbedatSanTauSeagrass communities
– 5 seagrass species (11 ha)
– Uncommon/rare
Ruppia maritima Halophila beccarii
Halophila ovalis HalophilaminorSeagrassbedinSanTauZosterajaponica
Distribution of seagrass in Hong Kong**
– 8 mangrove species
Acrostichum aureum
Acrostichum aureum
-8 mangrove species
(~ 510 ha)
Aegiceras corniculatum
Bruguiera gymnorrhiza
ExcoecariaagallochaLumnitzeraracemosaHeritieria littoralis
Avicennia marina
KandeliacandelMangroves
Salt glands of
Aegiceras corniculatum“Knee” of roots of
Bruguiera gymnorrhiza
Pneumatophores ofAvicinnia marina
AdropperofBruguieragymnorrhizaProp roots of
Kandelia obovata
MangrovesAdaptation
Distribution of Mangroves inHongKong
Other important coastal habitatsWetland – Brackish marshes, intertidal mudflats&mangrove(5% land area) most productive environment
Mai Po & Inner Deep Bay (1500 ha.)
– A shallow bay with extensive intertidal mudflatsbackedby mangal, tidal shrimp ponds (gei wais), fishponds,andreed bed (Phragmites australis)
– Largest mangal and reedbed in HongKong
Mai Po & Inner Deep Bay- Supports high diversity of birds, 440 species(75% of HK bird species)
– important feeding & resting grounds for migratorybirds,regularly supports some 50,000-60,000migratorywaterbirds in winter, important feeding&restingground.- Type locality for 13 species of invertebrates(1crabspeciesParasesarma maipoensis found nowhere else)- Holds 50 globally threatened species andnear-threatenedspecies (4 critically endangered, 7 endangered)- Housed 25% of the global populations of
Black-faced Spoonbill (Platalea minor), alsoSaunder’s gull (Chroicocephalus saundersi)
Spoon billed sandpiper (Calidris pygmaea)
Other Marine Resources – Mineralsextraction• Salt extraction : Long history (1700)
– salt fields in 6 areas [Kung Tong, Tai O(Lantau),SanHui & Wong Ka Wai (Tuen Mun), YimTinTsai(SaiKung), Yim Tin Tsai (Tai Po), YimLiuHa(ShaTauKok)]
– Production at Tai O peak in 1920- 1930, 70acres1488t/yr. Closed down around 1950- 1960
Other Marine Resources –SandExtraction• Marine sand is a valuable and important resourceinHongKong. • 1990-2003, ~ 270 millions m3 extractedandusedasmarine fill for reclamation projects. • Dredging of marine fill for land formation–EIA• Major impacts : – living community destroyed
– SS plume, increase turbidy
– release of pollutants
– disposal of surface mud
• EIAs, bunding during filling,
closed grabs for excavation
GPS opening of barge doors
Marine Sand Resources
Living space (industrialisation &urbanization)• Reclamations traced back to early Western Han
Dynasty (206 BC – 9 AD), beaches were turned
into salt pans. • Later conversion of wetland & mangroves into rice
paddi, then into fish ponds in Northwestern NewTerritories
• In mid 19th century land reclamation in coastal
areas for urban development
• 2016, 7000 ha. reclaimed (6% total), accommodate
27% population & 70% commercial activities.
Living space (industrialisation &urbanization)
Reclaimed land in Hong Kong
By Timothy135 – Own work,CC BY-SA 4.0,
https://commons.wikimedia.org/w/index.php?curid=100653106
Grey area – reclaimed land19701970-19802003-20051991-19981993-2018
Living space (industrialisation&urbanization)Pink – urban area
Living space (industrialisation&urbanization)• In 2020, 4th most densely populated city (7140/km2) [afterMonaco(25969/km2), Macau (20821/km2) &Singapore (8155/km2)• With continual influx of people fromMainland, pressurefordevelopment, great demand for housing, great pressuretomorelandsupply. • Marine reclamation easy way out for administrators–nomajorimpacts on existing land use & no need for privatelandresumptionand household resettlement
• a money-making business as the land to be reclaimed, formedandsold will generate a huge revenue for the Government notonlytopay off the infrastructure but also to go into the governmenttreasuryto support other activities. • Impacts irreversible, changes in water flow, alsoonsurroundingcommunities
• Development Plan: Lantau TomorrowVision project, SunnyBay,Lung Kwu Tan, Tuen Mun E&W, Tung ChungNTExt, SiuHoWan
Marine Transportation• Deep water harbour allows vessels to navigatesafely&easily, accommodate ultra large container vesselsatalltides.At Pearl River mouth, linked up with Mainland. • Hub port in the region : one of the top 10busiest containerports in the world. About 310 container liner servicesperweek to around 450 destinations worldwide. Totalcontainerthroughput 18.3 million TEUs in 2020. • Good infrastructure: Kwai Tsing Container Terminalswith9privately owned terminals, non-stop services24hoursaday7 days a week; and a variety of cargo handlingfacilities,handling some 14.5 million TEUs containersin2020representing 80% of the port container throughput.Remaining at mid-stream sites, River TradeTerminal,buoysanchorages, and private piers.
Marine Transportation• Hong Kong Shipping Register 4th largest (Panama,Marshall Is., Liberia) in the world provides qualityservicesto >2 600 vessels gross tonnage > 130 million(Dec2020)• fleet owned or managed by local ship ownersand~800maritime companies. • Judicial independence: ranked 8th among138jurisdictionsaround the world and 1st in Asia. Witha specialistAdmiralty List in the High Court, bilingual professionals,&many arbitration intuitions, ideal for commercialandshipping contract formation &dispute resolution. HongKong is a party to all key International MaritimeConventions. • Hong Kong, a major international financial centre,offersfirst-rate ship finance services. Also low&simpletaxregime.
Marine Transportation• According to the International ShippingCentreDevelopment Index (ISCD) (2020) HKranked4thasaninternational maritime centre trailing Singapore, Londonand Shanghai, with strong presence of shipowners,cargoowners and traders and a vibrant maritimeservicesclusteroffering comprehensive and professional services(shipfinancing, insurance and broking, shipmanagementandmaritime law). • International Chamber of Shipping set upitsChinaLiaison Office in Hong Kong in 2020, whichisthechamber’s first office outside of London. • Persons engaged in HK shipping industry: 49197Total business & incomes : HK$237.5billionTotal seaborne cargo throughput : 161.3milliontonnes(61.3%) (2019)
Communication Space
Undersea cables
• In 2000 the Office of the Communications Authority(OFCA) liberalized external facilities-basedtelecommunications market (open licensingregime)nolimit on the number of external facilities-basedlicenses.• 12- 13 out of 15 major submarine cable systemsintheregion chose Hong Kong as one of their landingsites.Hong Kong – a major telecommunications hubintheregion. • there are 8 submarine cable landing stations, 3atTseungKwan O, 2 at Tong Fuk, and 1each at DeepWaterBay,Chung Hom Kok and Cape D’Aguilar.
Communication Space UnderseacablesLocation of the Cable Landing Stations
Communication Space
(navigation, transport, pipelines, underseacables)
Treatment Type NT Kowloon Hong Kong Is. OutlyingIs. TotalPreliminary /
Screening (>6mm)
0 6 11 17Primary (-70%TSS
& 30%BOD)
0 22CEPT (-80%TSS
& 60%BOD)
3 1 15Major secondary 5 1 6In
19 1 1737Tertiary 0 1*1Total 27 10 13 2068Waste Disposal
• Sewage & waste water (16 Sewerage MasterPlans)- Serve 93% of population (2.8 X10
6m3
/day)
– Various types of treatment facilities
*In Ngong Ping, 2005: reclaimed water in a fish pond for rearingaquariumfish.Minor secondary
Waste Disposal
• Impact of effluent discharge depends onthecurrentanddilution capacity of the water body dischargedinto• 1996 transport of sewage effluent fromToloHarbourtoKai Tak Nullah (improvement of Tolowaterquality)• Harbour Area Treatment Scheme [1994-2001, 2009-2015 (Chemically Enhanced PrimaryTreatment+Chlorination disinfection, + Biological treatment)]
Dumping at Sea Ordinance Cap466(1995)This Ordinance provides for the control of activities that involvethedumping of substances or articles at sea in order topreventdamageto the marine environment. Prohibit dumping of any substances at sea except :
• Dredged material
• Sewage sludge
• Fish waste or material from industrial fish processingoperations• Vessels and platforms or other man-made structuresat sea• Inert inorganic geological material
• Organic material of natural origin
• Bulky items primarily comprising iron, steel, concreteandsimilarlyunharmful materials from small islands
Penalty: 1st conviction – Fine $200,000 + 6 monthimprisonment2nd conviction – Fine $500,000 + 2 yr. imprisonmentwith fine $10000 /day of proven continual operation
Disposal of dredgedmaterial
• Emergency dredging / maintenance dredgingofwatercourse allowed
• Applications for & allocation of marinedisposalspacemade to the Secretary of Marine Fill Committee.• Sediments classified based on their contaminantlevels(Chemical tests). [Category L, M&H+Biologicaltests]• Disposal sites : Open sea + Old burrowpit) / confined(East Sha Chau) [Trailing suction hopper dredgersmustuse a down-a-pipe disposal method, thedesignofwhichmust be approved in advance by DCE. ]
• Charge for private projects : 25 March2019Open Sea Disposal HK$1.92/m3
Others HK$96.00/m3
Disposal Sites for Dredged Materials
Disposal of SewageSludge• Previously dumped at sea
• 1995 DSO enacted, mostly disposedofat3landfills at South East NewTerritories(SENT),North East New Territories (NENT)andWestNew Territories (WENT). 2007–885t/day,2016 – 126 t/day
• In 2016, a self-sustained SludgeTreatmentFacility (T-Park) has been built inTsangTsui,Tuen Mun (2019 – 1200 t/dayfrom11STWsbyvessels / trucks) (Max. capacity2000tonnes/day, 4000 householdelectricity)
Sludge Treatment Facility (STF) at TsangTsui
Recreation, education &tourism• 41 gazetted beaches managed by LCSD(3 temporary closed at present) [
life guard, shark, unsafe]
• 49 other beaches suitable for swimming• Yacht racing in the harbour
• Snorkeling and diving in eastern waters
• Dolphin watching in western waters
• 6 Marine parks and 1 marine reserve
Energy production• Tidal difference small, tidal current relatively weak• May 2005 CLP proposed offshore wind farm, [EP2009]- 1% HK total power generation, up to 200MW, ~80,000households- 67x3MW or 40x5MW turbines, 1 offshore transformer platform&submarine cables (5 km east of Ninepin)
– offset 188,000 t CO2
, 595 t SO2
, 265 t NO2 &22t of part.matperyr.- Undecided – cost effectiveness
– Scheme of Control Agreement :
1 Oct 2018 to 31 Dec 2033
permitted rate of return 8% of
Average Net Fixed Assets
Energy production• 2008 HKElectric proposes a 100 MW(1.5%of total HKEgeneration) offshore wind farm in Southwest LammaChannel,4kmfrom Lamma Island (50,000 4-person households inHongKong)[EP 2010]
– 33 wind turbines, each 3-3.6 MW, in a 600-hectaresite- Offset 62,000 t coal;150,000 t CO2
; 520 t SO2
;&240t NO2peryr.- An offshore wind monitoring
station built in 2012
• Scheme of Control
Agreement :1 Jan 2019 – 31
Dec 2033, permitted rate of
return 8% ofAverage Net
Fixed Assets for that Year
