12.                   FISHERIES

 

12.1               Introduction

 

12.1.1         This section of the EIA presents details of the assessment of the potential impacts to fisheries resources within the study area and describes the sensitive receivers present, potential impacts from the project and recommends suitable mitigation measures. In order to achieve the aforementioned measures, the major objectives of the assessment are as follows:

 

¨             description of the physical environmental background;

¨             description and quantification as far as possible of the existing fisheries activities;

¨             identification of parameters and area that are important to fisheries;

¨             identification and quantification as far as possible of any direct or indirect and on-site or off-site impacts to fisheries; and

¨             proposals for any practicable alternatives or mitigation measures to prevent  or minimise adverse impacts on fisheries.

 

12.2               Relevant Legislation and Assessment Criteria

 

12.2.1         Relevant legislation applicable to this Study includes:

 

¨             the Marine Fish Culture Ordinance (Cap. 353) 1983 which regulates and protects marine fish culture zones (FCZ) that are designated under the ordinance. It is a criminal offence to discharge polluting substances into an FCZ;

 

¨             the Fisheries Protection Ordinance (Cap. 171) 1987 which regulates fishing activities for the conservation of fisheries resources and other marine life; and 

 

¨             reference was also made to Annexes 9 and 17 of the Technical Memorandum EIAO (Cap. 499) 1997 in order to determine the potential impacts to fisheries resources in the Study Area. The criteria include the following:

 

-           to prevent any significant impacts to sensitive fisheries areas particularly the nursery and spawning grounds of commercially important species of fish, crustaceans, molluscs and other marine life;

-           to prevent significant loss or interference with the use of fishing grounds and FCZ’s; and

-           to prevent significant impacts to local fishery resources and fishing activities.

 

12.2.2         A review of relevant EIA’s and reports has also been conducted in order to assist the assessment criteria. These reports include the following:

 

¨             New Airport Master Plan (Greiner-Maunsell, 1991);

¨             Feasibility Study & Environmental Impact Assessment for Aviation Fuel Pipeline (Montgomery Watson, 1996);

¨             Feasibility Study for Additional Cross-border Links Stage 2 (Mouchel, 1998);

¨             EIA for the Proposed Sand Extraction from The Brothers’ Marine Borrow Area (Hyder Consulting, 1998);

¨             EIA Study for Disposal of Contaminated Mud in the East Sha Chau Marine Borrow Pit (ERM, 1997, 2005);

¨             EA Study for Backfilling of Marine Borrow Pits at North of the Brothers (Mouchel, 2002);

¨             Route 10 North Lantau to Yuen Long Highway Investigation and Preliminary Design EIA (Mott Connell, 1999);

¨             Hong Kong- Zhuhai- Macao Bridge: Hong Kong Section and the North Lantau Highway Connection: Ecological Baseline Survey (Mouchel, 2004); and

¨             Port Survey 96/97 and Port Survey 2001/2002, Fisheries Management Division, AFCD (AFCD, 1998, 2003).

 

12.2.3         Reports from the ongoing environmental monitoring and audit at the contaminated mud pits at East of Sha Chau (Mouchel, 2001a, 2005b; Meinhardt, 2006b) also provide a large amount of relevant fisheries data and have also been reviewed. The fisheries data provided in the aforementioned EM&A study provides the most up to date information on the fisheries resources of the study area.

 

12.3               Baseline Conditions

 

12.3.1         Description of Physical Habitat

 

12.3.1.1   A detailed description of the physical marine habitat is presented in Section 7.4.2 and the key aspects are summarised below.  The PAFF is located within the western waters of Hong Kong that are highly influenced by the variable estuarine conditions of the Pearl River Delta and a well-scoured tidal channel running east-west (the Urmston Road).  Thus, the seabed in the area is predominantly made up of soft muds, although the scouring of the tidal channel along the Urmston Road provides some coarser habitat containing muddy shelly sand. The benthic habitat in the study area is, therefore, highly sediment laden, both in suspension and on the seabed, and existing fauna are dominated by representatives that tolerate these high ambient loads (see Section 7.4). The soft-bottom sediments characteristic of the study area are predicted to be moderately contaminated in places (see Section 6.2.5).  In terms of water quality, the Pearl River outputs significant nutrient loading resulting in generally eutrophic conditions (Section 6.2.4) and the predominantly estuarine fish inhabiting the study area are, therefore, already subjected to certain environmental stresses (notably relatively high suspended solid concentrations).

 

12.3.2         Capture Fisheries

 

12.3.2.1   Recent information on the capture fisheries is summarised in the Port Survey 96/97 (AFCD, 1998) and in the Report on Fisheries Resources and Fishing Operations in Hong Kong Waters (ERM, 1998). The PAFF pipeline and berthing jetty passes interfaces with two fishing areas, namely, the Tap Shek Kok and Lung Kwu Sha Chau fishing areas, as identified in the Port Survey 96/97 Report. The proposed 4.8km twin subsea pipeline is located approximately equally in each fishing area.  The two fishing areas within the PAFF study area are significantly different in size and comprised the following:

 

¨              Area 33 - Lung Kwu Sha Chau comprising an area of 3,616.46 ha; and

¨              Area 43 – Tap Shek Kok comprising an area of 822.57 ha.

 

12.3.2.2   The total value and ranking of the fisheries resources in each of these fishing areas that lie within the study area are presented below in Table 12.1. The Lung Kwu Sha Chau fishing area is of reasonably high value and ranks quite highly in terms of adult fished biomass and overall value per hectare on a Hong Kong wide basis. The fishing area at Tap Shek Kok is ranked lower and in terms of adult fish production is ranked 105 out of 189 fishing areas in Hong Kong.

 

Table 12.1  Fisheries Production in Each Fishing Area (all fishing vessels)

 

Fishing Area (ha)

Total Production

Production (ha-1)

Rank Production (ha-1)

Adult Fish (kg)

Fry (tails)

Value (HK$)

Adult Fish (kg)

Fry (tails)

Value (HK$)

Adult Fish

Fry

Value

Lung Kwu Sha Chau

3,616.46

651,700.0

-

11,828,364.8

180.2

-

3,270.71

53

-

82

Tap Shek Kok

822.57

66,218.3

-

1,958,466.6

80.5

-

2,380.9

105

-

98

Note: Based on the 189 fishing areas in Hong Kong waters (AFCD, 1998).

 

12.3.2.3   The two fishing areas are subunits of a wider sector area that occupies the sea around North of Lantau.  It is conceivable that impacts from the dredging operations could reach these wider regional areas and so a summary of the fishery for the region is included here. Thus, in terms of production by hectare the region ranks quite highly (4th out of 12 sectors) and is relatively valuable, however, the fry fishery is not nearly so productive (ranked 9 out of 12).   

 

12.3.2.4   Apart from a category labelled as mixed fish, the AFCD Port Survey 96/97 identifies the top four species caught in the region as scad (Caranx kalla), gizzard shad (Clupanodon punctatus), sardine (Sardinella jussieu) and croaker (Argyrosomus spp.).  These fish catches reflect the operations in the area, which are dominated by larger fishing vessels and notably hang trawlers fishing pelagic species. On a smaller scale, mixed fish species were also the most abundant fisheries resource in each of the fishing areas, followed by shrimp scad, gizzard shad and sardine (Lung Kwu Sha Chau) and gizzard shad, lionhead and croaker (Tap Shek Kok). A summary of the top ten adult fisheries resources caught in each fishing area is presented below in Table 12.2.

 

Table 12.2  Most Abundant Adult Fisheries Resources from the Study Area (by Biomass)

 

Rank by Biomass

Fishing Area

Lung Kwu Sha Chau

Tap Shek Kok

1

Mixed Species

Mixed Species

2

Caranx kalla (shrimp scad)

ClupanodonPunctatus(gizzard shad)

3

Clupanodon Punctatus (gizzard shad)

Collichthys lucida (lionhead)

4

Sardinella jussieu (sardine)

Argyrosomus spp. (croaker)

5

Trichiurus haumela (hairtail)

Mugil affinis (mullet)

6

Mugil affinis (mullet)

Caranx kalla (shrimp scad)

7

Argyrosomus spp. (croaker)

Acetes spp. (silver shrimp)

8

Collichthys lucida (lionhead)

Platycephalus indicus (flathead)

9

Decapterus lajang (scad)

Ilisha elongata(white herring)

10

Stolephorus spp. (anchovy)

Eleutheronema tetradactylus (threadfin)

Note: Mixed species is mixed fish considered of lower commercial value. Source: Based on Port Survey 96/87.

 

12.3.2.5   The more recent Port Survey 2001/2002 (AFCD, 2003) present the survey results in density grid, as shown in Figure 12.1, instead of fishing areas. With respect to Figure 12.1, essentially only cells B5 (Sha Chau) and C4 (Tak Shek Kok) would be affected by the proposed dredging works. The patterns revealed in Port Survey 2001/2002 were essentially the same as Port Survey 96/97 and in generally the Sha Chau area was more productive and the products were also more valuable compared to Tap Shek Kok. Although there were more small boats (<15m) operating in the two areas than the large vessel (>15m), the production of the small boat was low and ranked the second lowest across Hong Kong waters. Thus, impacts from the dredging operations to small boat operators are likely to be localised around the study area and are not likely to range wider.  As the area is not the major operating area for the large trawling vessels (>15m), impacts to them would also be limited. The results of the Port Survey 2001/2002 are summarised in Table 12.3 below:

 

Table 12.3  Catch Statistics of Sha Chau and Tap Shek Kok, Port Survey 2001/2002

 

Cell1(Area)

B5 (Sha Chau)

Rank2

C4 (Tap Shek Kok)

Rank2

No. of Vessels

100-400

3/6

100-400

3/6

Small Boat <15m)

100-400

3/6

100-400

3/6

Large Vessel (>15m)

50-100

4/6

10-50

5/6

Total Adult Fish

200-400 kg/ha

3/6

50-100

5/6

Production

5,000-10,000 $/kg

2/6

1,000 - 2,000 $/kg

4/6

By small boat (<15m)

50-100 kg/ha

5/6

0-50 kg /ha

5/6

By large vessel (>15m)

100-200 kg/ha

3/6

0-50 kg/ ha

6/6

Fry production

-

-

-

-

Main Catch

shrimp: 20-40 kg/ha

3/6

shrimp: 5-10 kg/ha

5/6

 

sciaenidae: 20-40 kg/ha

3/6

Clupeidae: 5-10 kg/ha

5/6

 

 

 

Siganidae: 5-10 kg/ha

5/6

Note: 1Cell number refers to grid in Figure 12.1; 2A scale of 1-6 was used in Port Survey 2001/2002 and the 1st is the highest rank.

 

12.3.2.6   Trawling is conducted as part of the ongoing EM&A programme for the contaminated mud pits in locations near the study area at sites around Lung Kwu Chau, off the airport and around the mud pits. The trawling locations are presented in Figure 12.2. The most recent fisheries data covering both the dry (January-February 2005; Mouchel, 2005b) and wet (October 2005; Meinhardt, 2006b) seasons from the Northwestern waters.

 

12.3.2.7   The January-February 2005 dry season survey recorded a total of 177 different species. Of these faunal groups, bivalves, crabs, fish, gastropods, shrimps (including mantis shrimp) and prawns were the most abundant. The gastropods were numerically dominant and 3,163 individuals were trawled in January-February 2005. Crabs were the second most dominant species and 2,085 individuals were recorded in the dry season, although it should be noted that not all these crabs and gastropods are commercial species.  Fish were also abundant and 2,638 individuals were recorded in the dry season and were the most diverse group represented by 66 different species. In terms of numerical dominance, the most common fish recorded were the croaker (Johnius macrorhynus), the gobies (Trypauchen vagina), Saddleback silver-biddy (Gerres lucidus (=limbatus)) and mullet (Valamugil formosae). The commercially important mantis shrimps (mostly Oratosquilla interrupta) and prawns (Metapenaeus spp. and Penaeus spp.) were also numerically abundant components of the trawls. The commercially important species (cephalopds, crabs, mantis shrimp, shrimp and fish) trawled from locations around Sha Chau during the January-February 2005 dry season are presented below in Table 12.4.

 

Table 12.4  Species Composition and Abundance of Individuals (Total Counts) from Trawling in Dry Season (January-February 2005)

 

Group

Species

FS1

FS2

FS3

FS4

FS5

FS6

Total

Cephalopod

Loligo sp.

 

2

7

3

4

5

21

 

Octopus sp.

 

 

3

 

1

2

6

 

Sepiella japonica

 

 

 

 

 

1

1

 

Sepiella sp.

 

 

1

2

 

1

4

Cephalopod Total

 

 

2

11

5

5

9

32

Crab

Charybdis acuta

13

 

3

 

11

12

39

 

Charybdis affinis

1

4

3

 

19

12

39

 

Charybdis anisodon

 

 

 

 

1

 

1

 

Charybdis cruciata

5

2

7

1

16

14

45

 

Charybdis hellerii

 

3

 

 

4

 

7

 

Charybdis japonica

111

151

85

50

510

222

1,129

 

Charybdis truncata

 

7

7

1

9

21

45

 

Charybdis variegata

5

9

 

3

2

12

31

 

Clibanarius sp.

1

8

24

27

34

39

133

 

Diogenes sp.

 

11

 

3

41

 

55

 

Doclea ovis

 

2

 

 

 

 

2

 

Dorippe polita

 

1

 

 

 

 

1

 

Eriochier sp.

1

 

 

 

 

 

1

 

Ethusa indica

4

1

14

19

6

10

54

 

Eucrate costata

14

28

3

2

30

5

82

 

Eucrate crenata

3

6

 

2

7

1

19

 

Galene bispinosa

7

 

4

3

1

 

15

 

Goniohellenus vadorum

 

11

40

35

 

3

89

 

Leucosia vittata

 

6

 

 

3

21

30

 

Macrophthalmus japonicus

 

 

 

1

 

1

2

 

Macrophthalmus latreillei

 

1

 

 

 

 

1

 

Platylambrus validus

 

4

9

9

4

50

76

 

Portunus hastatoides

 

2

5

3

9

4

23

 

Portunus pelagicus

 

 

 

 

9

14

23

 

Procelain crab

 

2

1

2

28

91

124

 

Scalopidia spinosipes

 

 

 

 

 

1

1

 

Thalamita sima

 

 

2

 

2

2

6

 

Typhlocarcinops denticarpes

 

 

1

 

 

 

1

 

Typhlocarcinus nudus

5

4

 

 

 

 

9

 

Typhlocarcinus villosus

1

 

 

1

 

 

2

Crab Total

 

171

263

208

162

746

535

2,085

Fish

Acentrogobius caninus

5

3

14

11

83

25

141

 

Ambassis gymnocephalus

23

 

 

 

 

 

23

 

Amblychaeturichthys hexanema

6

10

1

2

3

 

22

 

Apogon kiensis

 

 

 

 

2

 

2

 

Apogon lineatus

 

 

 

 

 

1

1

 

Apogon pseudotaeniatus

 

1

 

 

 

 

1

 

Arnoglossus tenuis

 

 

1

1

9

5

16

 

Chaeturichthys stigmatias

15

25

4

5

1

 

50

 

Chrysochir aureus

 

 

1

 

 

 

1

 

Coilia grayii

9

27

2

 

 

1

39

 

Collichthys lucidus

2

8

2

 

6

1

19

 

Cryptocentrus filifer

 

 

 

 

20

1

21

 

Cynoglossus arel

20

15

6

5

47

26

119

 

Cynoglossus gracilis

 

 

 

 

 

1

1

 

Cynoglossus itinus

 

 

 

 

 

1

1

 

Cynoglossus joyneri

21

18

13

7

10

1

70

 

Cynoglossus puncticeps

 

2

 

 

2

2

6

 

Cynoglossus semilaevis

10

6

1

 

8

6

31

 

Dasyatis bennettii

 

 

 

 

 

4

4

 

Dasyatis zugei

 

 

1

 

 

 

1

 

Dendrophysa russelii

17

26

15

29

12

19

118

 

Epinephelus bruneus

 

 

 

 

1

 

1

 

Gerres lucidus

 

 

7

10

20

145

182

 

Gymnothorax reevesii

 

 

 

 

1

 

1

 

Ilisha elongata

2

5

 

 

 

 

7

 

Inegocia japonica

 

 

 

 

4

3

7

 

Inimicus japonicus

 

 

 

 

1

2

3

 

Johnius belangerii

1

11

1

 

2

15

30

 

Johnius macrorhynus

12

15

134

59

86

222

528

 

Larimichthys polyactis

 

 

2

 

 

 

2

 

Lateolabrax japonicus

 

1

 

 

 

1

2

 

Leiognathus brevirostris

1

1

1

1

8

38

50

 

Liza affinis

 

 

 

1

 

 

1

 

Muraenesox cinereus

 

1

 

1

1

 

3

 

Nemipterus japonicus

 

 

1

1

1

 

3

 

Ophichthus celebicus

 

 

 

 

1

 

1

 

Otolithes ruber

 

 

4

3

1

2

10

 

Oxyurichthys tentacularis

4

 

8

13

7

3

35

 

Parachaeturichthys polynema

8

50

4

3

13

2

80

 

Pennahia argentata

 

 

1

2

3

2

8

 

Pisodonophis cancrivorus

 

 

 

 

1

 

1

 

Platycephalus indicus

4

4

16

14

23

24

85

 

Plotosus lineatus

 

 

1

 

 

1

2

 

Polydactylus sextarius

 

1

5

15

5

5

31

 

Prionobutis koilomatodon

 

 

 

 

 

1

1

 

Pseudorhombus arsius

 

 

1

 

 

1

2

 

Saurida elongata

 

 

 

2

 

 

2

 

Scatophagus argus

 

 

 

 

 

4

4

 

Sebastiscus albofasciatus

 

 

 

 

 

1

1

 

Sebastiscus marmoratus

 

 

 

 

 

1

1

 

Siganus canaliculatus

 

1

2

 

 

5

8

 

Sillago sihama

1

 

 

1

9

27

38

 

Solea ovata

 

3

3

2

43

68

119

 

Syngnathus schlegeli

3

3

5

6

3

 

20

 

Takifugu niphobles

 

 

 

1

 

 

1

 

Takifugu oblongus

 

 

 

 

 

3

3

 

Takifugu poecilonotus

 

 

 

 

 

1

1

 

Takifugu xanthopterus

 

 

 

 

 

1

1

 

Thryssa chefuensis

 

 

 

 

 

1

1

 

Thryssa hamiltonii

 

4

3

 

10

2

19

 

Trachycephalus uranoscopa

1

1

3

2

18

43

68

 

Trichiurus lepturus

1

 

 

 

 

1

2

 

Trypauchen vagina

155

122

10

20

66

54

427

 

Uroconger lepturus

 

 

1

2