CLA JETTY HABITAT ASSESSMENT - epa.wa.gov.au · CLA Jetty Habitat Assessment p. iv Rio Tinto EXECUTIVE SUMMARY The benthic habitats at nine locations along the Cape Lambert (CLA)

CLA JETTY HABITAT ASSESSMENT

BRISBANE | PERTH | SINGAPORE | PAPUA NEW GUINEA RIO TINTO

FINAL

—

16 NOV 2018

© Hydrobiology Pty Ltd 2018

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It is not for public circulation or publication or to be used by any third party without the express permission of either the

Client or Hydrobiology Pty. Ltd. The concepts and information contained in this document are the property of

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Hydrobiology Pty Ltd constitutes an infringement of copyright.

While the findings presented in this report are based on information that Hydrobiology considers reliable unless stated

otherwise, the accuracy and completeness of source information cannot be guaranteed. Furthermore, the information

compiled in this report addresses the specific needs of the client, so may not address the needs of third parties using

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provided in this report do so entirely at their own risk.

T H I S C O M P A N Y I S R E G I S T E R E D F O R G S T .

S T R E E T R E G I S T E R E D P O S T A L C O N T A C T

25 Southport Street

West Leederville 6007

WESTERN AUSTRALIA

c/- de Blonk Smith and

Young Accountants

GPO 119, Brisbane 4001

QUEENSLAND

PO Box 1034


WESTERN AUSTRALIA

+61 (0)8 6218 0900 P

[email protected]

A B N 68 120 964 650 www.hydrobiology.biz

DOCUMENT CONTROL INFORMATION

D A T E P R I N T E D J O B N U M B E R R E P O R T N U M B E R

RTI1803 f1b

P R O J E C T T I T L E CLA Jetty Habitat Assessment

P R O J E C T S U B T I T L E

P R O J E C T M A N A G E R Shirley Dawe

F I L E N A M E RTI-Rio Tinto Iron Ore\RTI1802 CL Habitat mapping\ RTI1802 CLA Jetty habitat_v1

S T A T U S O R I G I N A T O R / S R E V I E W E D A U T H O R I S E D D A T E

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CLA Jetty Habitat Assessment p. iv

Rio Tinto www.hydrobiology.biz

EXECUTIVE SUMMARY

The benthic habitats at nine locations along the Cape Lambert (CLA) Jetty were mapped using side-

scan, down-beam sonar, a drop camera system and sediment (grab) samples where possible. The

data was assessed to determine the substrate type and the assemblage of biota present. The findings

of this report are intended to inform the activities of the proposed Jetty strengthening project. Table 1

below provides a summary of the major findings.

Habitats were dominated by smooth sand substrate with occasional patches of macroalgae and soft

coral. Hard coral substrate was restricted to the southernmost (shoreward) location (sites 5-8).

Overall, macro-benthic habitats in the vicinity of the CLA Jetty are typical of the wider area, hence the

piling works are unlikely to pose a significant threat to the communities present. Impacts associated

with jack-up barges are considered likely to be insignificant on a wide habitat scale given the relatively

small footprint of the barge legs and the patchy/localised nature of benthic primary producer habitat

in the area. The habitat map is provided as Figure 3-24 in Section 3.3.

CLA Jetty Habitat Assessment p. v


Table 1 Summary of habitat assessment finding for 9 locations along Cape Lambert (CLA) Jetty.

Location Sites

Depth

(m)

Roughness

(relative)

Hardness

(relative) Substrate

Figure

References

1 5-8 7 m Moderate-

rougher

Moderate-harder Sand, rock with turf

algae, macroalgae,

soft and sparse hard

coral (7 & 8).

Figure 3-6

Figure 3-8

2 1-4 11 m Smooth-

moderate

Moderate Sand, grit, rock,

macroalgae.

Figure 3-10

Figure 3-11

3 9-12 11 m Smooth-

moderate

Moderate-harder Sand, rock with turf

algae, sponge.

Figure 3-12

Figure 3-13

4 13-

16

10 m Moderate Softer Sand, mud, gravel. Figure 3-14

Figure 3-15

5 17-

20

9.5 m Moderate Softer –

moderate/harder

mix

Sand, mud, gravel,

macroalgae,

seagrass - Halophila

(17)

Figure 3-16

Figure 3-17

6 21-

24

9 m Moderate Moderate Sand, mud, gravel,

macroalgae.

Figure 3-18

Figure 3-19

7 25-

28

9 m Moderate-

rougher

Softer-moderate Sand, mud, gravel

macroalgae, soft

coral (25).

Figure 3-20

Figure 3-21

8 29-

32

12 m Moderate-

smooth

Moderate-harder Sand, gravel,

macroalgae.

Figure 3-22

9 33-

36

12.5

m

Smooth Softer Sonar indicates

smooth mud-sand

type bottom (low-

moderate hardness;

no surface features)

Figure 3-23

CLA Jetty Habitat Assessment p. vi


Contents

EXECUTIVE SUMMARY IV

1. INTRODUCTION 1

2. METHODOLOGY 2

2.1 STUDY AREA 2

2.2 HABITAT MAPPING 2

2.2.1 Sonar Methods 2

3. RESULTS 4

3.1 Benthic Sonar Maps 4

3.2 Per Location Benthic Habitat Characterisation 7

3.2.1 Location 1 – sites 5-8 (190m from shore) 9




3.2.5 Location 5 – sites 17-20 (1.1km from shore) 15




3.2.9 Location 9 – sites 33-36 (2km from shore) 19

3.3 Combined Habitat Map 19

4. DISCUSSION 22

CLA Jetty Habitat Assessment p. vii


tables

Table 1 Summary of habitat assessment finding for 9 locations along

Cape Lambert Jetty A. ...................................................................... v

figures

Figure 3-1 Bathymetic map for the CLA Jetty showing the locations of

each proposed new pile site. ................................................ 5

Figure 3-2 Relative surface hardness map for the CLA Jetty showing

locations of each new pile site. ............................................. 6

Figure 3-3 Hardness (E2) from down-beam sonar at each site, as a

percentage of the entire mapped area hardness. ............. 6

Figure 3-4 Relative surface roughness map for the CLA Jetty showing

locations of each new pile site. ............................................. 7

Figure 3-5 Site 5 oblique view showing patchy hard coral, soft coral,

macroalgae and sediment substrate ................................... 9

Figure 3-6 Images of the sea floor at sites 5 showing rocky areas with

hard coral (left) and 6 (right) showing smoother turf algae

substrate. ............................................................................... 10

Figure 3-7 Images of the sea floor at sites 7 (left) and 8 (right)

showing rocky areas with hard coral. ................................ 10

Figure 3-8 Sonar data for new pile sites 5-8 (southern-most location).

................................................................................................. 10

Figure 3-9 Down image of a 40m stretch of seafloor near site 5

showing distribution of macro-benthic habitat and

smooth substrate ................................................................. 11

Figure 3-10 Image of the sea floor at site 4 showing mostly bare sand

with some macroalgae. ........................................................ 12

Figure 3-11 Sonar data for new pile sites 1-4. ....................................... 12

Figure 3-12 Image of the sea floor at site 10 showing sandy substrate

with a small amount of macroalgae and sponge. ............ 13

Figure 3-13 Sonar data for new pile sites 9-12. ..................................... 13

Figure 3-14 Image of the sea floor at site 15 showing bare muddy

substrate and surface grit. .................................................. 14

Figure 3-15 Sonar data for new pile sites 13-16. ................................... 14

Figure 3-16 Images of the sea floor at site 17 (left) showing a patch of

a small seagrass species and site 18 (right) showing the

muddy substrate covered by grit. ...................................... 15


CLA Jetty Habitat Assessment p. viii


Figure 3-18 Images of the sea floor at sites 21 from above (left) and

side on (right) showing the areas of turfing macroalgae

and the larger, more vertical patches. ............................... 16


Figure 3-20 Images from the sea floor at sites 28 (left) and 27 (right)

showing the extensive assemblages of soft coral, sponges

and macroalgae. ................................................................... 17




Figure 3-24 Benthic habitat map along CLA Jetty derived from sonar,

drop camera and sediment sampling. ............................... 20

Figure 3-25 Combined wide area benthic habitat map derived from

EOMAP (2015) satellite imagery analysis and Hydrobiology

sonar, drop camera and sediment sampling. ................... 21

CLA Jetty Habitat Assessment p. 1


1. INTRODUCTION Rio Tinto is planning a Jetty strengthening project along the length of the CLA Jetty at Cape Lambert as

part of a broader project referred to as the Cape Lambert Port A Marine Structures Refurbishment

Project. The Jetty strengthening project will involve placing two piles either side of the Jetty. This is

planned to occur at nine locations evenly spread along the length of the Jetty, resulting in the addition

of 36 piles in total.

Hydrobiology was commissioned to undertake an assessment of the marine habitats in each of these

locations for input into the environmental approvals process.

This report has been prepared for Rio Tinto which is acting on behalf of the proponent Robe River

Mining Co. Pty Limited, as a member of the Rio Tinto Group of companies. The Rio Tinto Group (Rio

Tinto) is managing the environmental impact assessment and approvals process (for which this report

has been prepared) on behalf of the proponent.



2. METHODOLOGY 2.1 STUDY AREA Cape Lambert is located approximately 40 km from Karratha, situated at 20° 35’ 34”, 117° 10’ 50”. The

CLA Jetty/Wharf structure is located on the northern coast of the cape, extending approximately

2.9 km from the shore.

The study area comprised nine locations at approximately 240 m intervals along the Jetty consisting of

four piles at each location (two either side of the Jetty) with each pile numbered 1-36. Habitat

assessments were made for the 9 locations only, considering the 4 pile sites as one cluster within a

location. Images are available from the 36 locations if required (except where operations restricted

access); however due to proximity they are being dealt with as a single habitat ‘type’.

2.2 HABITAT MAPPING Habitat at each of the predetermined pile locations was characterised using sonar, drop camera and

sediment grabs.

A drop camera system was used to photograph the substrate and ground truth the habitat types.

These images were analysed to determine the ecological components in conjunction with

photographs of sediment (grab) samples taken at each site.

2.2.1 SONAR METHODS High-resolution sonar data were collected using a Humminbird Helix-9 MEGA with combined GPS,

side-scan, down-imaging and down-beam data sources. The down-beam data were collected at

200 khz to enable bottom hardness, bottom roughness and depth information to obtained. Side-scan

and down-imaging data were collected at 1200 khz which provided high-resolution imagery suitable

for visual interpretation of bottom habitat types and geomorphic bed forms.



The transducer was located on the port side of the survey vessel (Miss Rani) approximately 1m below

the water line when the vessel was loaded, at the level of the boat bottom.

The sonar data was saved to the Humminbird .SON file format as follows:

• B001.SON – 200 khz down beam

• B002.SON – 1200 khz left (port) side-scan

• B003.SON - 1200 khz right (starboard) side-scan

• B004.SON – 1200 khz down-imaging

2.2.1.1 BOTTOM HARDNESS, ROUGHNESS AND DEPTH

The .SON file data was imported into the software package Reefmaster for extraction of the following

data sets:

• E2 Bottom hardness – derived from the second full echo return, the principle bottom hardness

measure used in this study.

• Peak SV bottom hardness – Derived from the first peak echo return, also measures bottom hardness

but less sensitive across the hardness range. Not as useful for the current study area due to the wide

range of bottom hardness from soft muds to hard rock bottom.

• E1 Bottom roughness – Derived from the first echo return immediately after the Peak SV return. This

is a measure of the scatter of sound energy once it hits the bottom and therefore can be a proxy for

bottom roughness. Smooth muds and sand will have a lower roughness value than sand ripples,

cobbles and boulders etc.

• Depth – Derived from the location of the top of the Peak SV range.

Changes in benthic features were assessed using the high-resolution side-scan and down-beam sonar

(1200 kHz) along a single transect line, perpendicular to the pile locations either side of the Jetty. The

data was used to determine the presence of important ecological components including macro-algae

and hard or soft corals. The down and side-scan images were used to created maps categorising

bathymetry, roughness and hardness for the area surrounding the Jetty.



3. RESULTS 3.1 BENTHIC SONAR MAPS Maps to show changes in bathymetry, relative hardness and roughness of the substrate surrounding

the Jetty were created using the sonar data.

Depth (Figure 3-1) increases with distance from the shore; shallowest at location 1 (6-9 m), remaining

relatively uniform between locations 2 to 7 (9-12 m) and then becoming deeper at locations 8 & 9 (15-

18 m).

Bottom hardness as measured by sonar does not have set units and is presented here as relative

hardness for the area mapped. All values represent the “percent hardness” with 0 being the softest

area in the mapped location and 100 representing the hardest area. Hardness (Figure 3-2) is mostly

moderate across the proposed new pile locations though variable. Figure 3-3 displays a bar chart of

the relative hardness recorded at each pile site. Areas of harder substrate occur further from the

shore at locations 7 to 12 while the hardest substrates occur very close to the shore in a small patch

south of location 1. Apart from corals and rocky substrate closer to shore in the harder zone, no

distinct pattern of habitat type could be related to bottom hardness along the length of the Jetty.

A similar pattern is observed for roughness (Figure 3-3). Areas of greater roughness occur south of

location 1 at the shoreward end of the Jetty and then decrease offshore to remain relatively uniform

between locations 3 to 6. Roughness then increases at location 7 and becomes smoother towards

locations 8 and 9.



Figure 3-1 Bathymetic map for the CLA Jetty showing the locations of each proposed new pile site.

36

35

34

33

32

31

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

15

14

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12

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10

9

8

7

6

5

4

3

2

1

9.

8.

7.

6.

5.

4.

3.

2.

1.

New pile cutoff sites

1. Site Labels

Sites

1. Location Labels

Bathymetry

[not for navigation]

[not tide corrected]

Depth (m)

0-3

3-6

6-9

9-12

12-15

15-18

18-21

21-24

Background:

Virtual Earth imagery

MGA zone 50; GDA94

519000 m 520000 m 521000 m

519000 m 520000 m 521000 m

7723000 m

7724000 m

7723000 m

7724000 m

N

0 500 m



Figure 3-2 Relative surface hardness map for the CLA Jetty showing locations of each new pile site.

Figure 3-3 Hardness (E2) from down-beam sonar at each site, as a percentage of the entire mapped area

hardness.

36

35

34

33

32

31

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

9.

8.

7.

6.

5.

4.

3.

2.

1.


Sites

1. Location labels

E2 - Hardness

Areas : Relative percentage

< 5th

5 - 25th

25 - 50th

50 - 75th

75 - 95th

> 95th

Background:


MGA zone 50; GDA94

519000 m 520000 m 521000 m

519000 m 520000 m 521000 m

7723000 m

7724000 m

7723000 m

7724000 m

N

0 500 m

0%

10%

20%

30%

40%

50%

60%

70%

80%

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36

Per

cen

tage

of

sam

ple

set

(Har

dn

ess-

E2)

Percentile

Percentile

Hardest

Softest



Figure 3-4 Relative surface roughness map for the CLA Jetty showing locations of each new pile site.

3.2 PER LOCATION BENTHIC HABITAT CHARACTERISATION The following section includes drop camera still images and a combination of down-beam imaging

sonar (looking directly down from the boat vertically) and side-scan sonar imaging (looking down and

across the substrate horizontally) at each “location” along the CLA Jetty. Each location includes a set of

4 proposed new pile sites. As these sets of 4 sites are relatively close to each other they have been

grouped as one of 9 “locations” along the CLA Jetty for the purposes of assessing the benthic habitat

type.

It can be difficult to interpret down-beam and side-scan imagery. To assist with interpretation of this

section the following figure has been annotated as an example of the arrangement and features of

this type of imagery.

36

35

34

33

32

31

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

9.

8.

7.

6.

5.

4.

3.

2.

1.


Sites

1. Location numbers

E - Roughness

Areas : Relative VALUE

55.1 (smoother)

66.4

77.7

89

100.3

111.6

122.9 (rougher)

Background:


MGA zone 50; GDA94

519000 m 520000 m 521000 m

519000 m 520000 m 521000 m

7723000 m

7724000 m

7723000 m

7724000 m

N

0 500 m



Example figure to interpret sonar images:

Map Down-image Side-scan image (Jetty side)

Vessel

location

Sites



3.2.1 LOCATION 1 – SITES 5-8 (190M FROM SHORE) Location 1 is the only area with hard coral species present (~5% coverage). Rock covered by turf algae

is interspersed by plating and encrusting coral colonies at sites 5 (Figure 3-5 and Figure 3-6), 7 and 8

(Figure 3-7). Site 6 displayed a smoother substrate dominated by turf algae (Figure 3-6). The sonar

imagery showed areas of smooth substrate interspersed with low macro-benthic habitat (e.g.

organisms such as soft/hard corals and macroalgae that project above the seafloor)/rocks (Figure 3-8).

To illustrate the patchy nature of the macro-benthic habitat at site 5, Figure 3-9 shows a sonar down-

image ~40 m stretch of seafloor in the vicinity with smooth substrate and macro-benthic habitat noted

along its length.

Figure 3-5 Site 5 oblique view showing patchy hard coral, soft coral, macroalgae and sediment substrate



Figure 3-6 Images of the sea floor at sites 5 showing rocky areas with hard coral (left) and 6 (right) showing

smoother turf algae substrate.

Figure 3-7 Images of the sea floor at sites 7 (left) and 8 (right) showing rocky areas with hard coral.

Figure 3-8 Sonar data for new pile sites 5-8 (southern-most location).



Figure 3-9 Down image of a 40 m stretch of seafloor near site 5 showing distribution of macro-benthic habitat

and smooth substrate

Macro-benthic

habitat

Macro-benthic

habitat

Macro-benthic

habitat

Smooth

substrate Smooth

substrate



3.2.2 LOCATION 2 – SITES 1-4 (420M FROM SHORE) This location is characterised by a smooth, soft substrate. Sand covered with a layer of grit is

interrupted only by a small patch of rock covered with macro algal species at site 4.

Figure 3-10 Image of the sea floor at site 4 showing mostly bare sand with some macroalgae.

Figure 3-11 Sonar data for new pile sites 1-4.

Existing piles

Existing piles

Smooth

substrate



3.2.3 LOCATION 3 – SITES 9-12 (660M FROM SHORE) This location is characterised by soft, sandy substrates. All sites are bare except for site 10 which

contains a rocky patch with macroalgae and sponge.

Figure 3-12 Image of the sea floor at site 10 showing sandy substrate with a small amount of macroalgae and

sponge.


Existing piles



3.2.4 LOCATION 4 – SITES 13-16 (900M FROM SHORE) Location 4 is relatively featureless with the substrate transitioning to softer silt and mud covered by

fine grit.

Figure 3-14 Image of the sea floor at site 15 showing bare muddy substrate and surface grit.


Existing piles

Existing piles



3.2.5 LOCATION 5 – SITES 17-20 (1.1KM FROM SHORE) Patches of seagrass (Halophila sp.) are present over muddy substrates at site 17. The remaining sites

are bare, with only coarse grit and sparse macroalgae.

Figure 3-16 Images of the sea floor at site 17 (left) showing a patch of a small seagrass species and site 18 (right)

showing the muddy substrate covered by grit.


Existing piles



3.2.6 LOCATION 6 – SITES 21-24 (1.4KM FROM SHORE) Location 6 is characterised by muddy substrates with coarse gravel. This is covered by expanses of

low-lying macroalgae and some larger stands extending into the water column.

Figure 3-18 Images of the sea floor at sites 21 from above (left) and side on (right) showing the areas of turfing

macroalgae and the larger, more vertical patches.


Existing piles

Existing piles Macroalgae



3.2.7 LOCATION 7 – SITES 25-28 (1.6KM FROM SHORE) This location has many features including rocky patches covered with turf algae at all sites, soft coral

at sites 25 & 26 and, sponges and macroalgae at sites 27 & 28. The substrate is soft mud containing

coarse gravel.

Figure 3-20 Images from the sea floor at sites 28 (left) and 27 (right) showing the extensive assemblages of soft

coral, sponges and macroalgae.


Existing piles

Rough

substrate

showing soft

corals

Rough

substrate

showing soft

corals

Existing piles



3.2.8 LOCATION 8 – SITES 29-32 (1.85KM FROM SHORE) This location is relatively featureless showing only smooth substrate likely to be fine sediment

material.


Smooth

substrate

Existing piles

Existing piles

Smooth

substrate



3.2.9 LOCATION 9 – SITES 33-36 (2KM FROM SHORE) This location is the most seaward and deepest of the survey locations, about 100 m before the start of

the dredged berth pockets. The location displayed moderate hardness and a smooth substrate

indicating a sand type habitat.


3.3 COMBINED HABITAT MAP The sonar, drop camera and sediment sampling data were combined for the length of the CLA Jetty to

generate a benthic habitat map (Figure 3-24). The EOMAP (2015)1 benthic habitat map is underlaid on

the Hydrobiology habitat mapping for reference and to establish the local extent of these types of

habitats in the area. The coral habitat to the south of the study area is well represented in this area as

well as in the wider Cape Lambert region (Figure 3-25). The new mapping by Hydrobiology shows

more detail with respect to patches of macroalgae and soft coral areas within the sandy/smooth

substrate areas mapped by EOMAP (2015). The macroalgae and soft coral areas are also widely

mapped though are likely to exist as patches throughout the “sand” habitat areas mapped by EOMAP

(2015).

1 EOMAP (2015). Delivery Report: Seafloor habitat classification and bathymetry mapping - Cape Lambert, Australia. Report

prepared for Rio Tinto. August 2018.



Figure 3-24 Benthic habitat map along CLA Jetty derived from sonar, drop camera and sediment sampling.

9.

8.

7.

6.

5.

4.

3.

2.

1.


Sites

1. Location numbers

Habitat classes (CLA new)

Smooth sediment - sand and silt

Soft coral and macroalgae over pavement

Patchy hard coral, soft coral, macroalgae

and smooth sediment/pavement

Background: EOMAP 2015

SFC_AUS_CapeLambert_RioTinto

_2012_2015_WVIE2_LSAT8

Areas : Class_name

Coral

Dredged Area / canal

Dumping Site

Marine construction

Mudflats

Pavement partly covered by macroalgae and coral

Sand and silt

Seagrass


MGA zone 50; GDA94

519000 m 520000 m 521000 m

519000 m 520000 m 521000 m

7723000 m

7724000 m

7723000 m

7724000 m

N

0 500 m



Figure 3-25 Combined wide area benthic habitat map derived from EOMAP (2015) satellite imagery analysis and Hydrobiology sonar, drop camera and sediment

sampling.

9.8.

7.

6.

5.

4.

3.

2.

1.


Sites

1. Location numbers

Habitat classes (CLA new)

Smooth sediment - sand and silt

Soft coral and macroalgae over pavement

Patchy hard coral, soft coral, macroalgae

and smooth sediment/pavement

Background: EOMAP 2015

SFC_AUS_CapeLambert_RioTinto

_2012_2015_WVIE2_LSAT8

Areas : Class_name

Coral

Dredged Area / canal

Dumping Site

Marine construction

Mudflats

Pavement partly covered by macroalgae and coral

Sand and silt

Seagrass


MGA zone 50; GDA940 1 km

516000 m 517000 m 518000 m 519000 m 520000 m 521000 m 522000 m 523000 m 524000 m 525000 m

516000 m 517000 m 518000 m 519000 m 520000 m 521000 m 522000 m 523000 m 524000 m 525000 m

7722000 m

7723000 m

7724000 m

7725000 m

7726000 m

7727000 m

7728000 m

7722000 m

7723000 m

7724000 m

7725000 m

7726000 m

7727000 m

7728000 m

N

0 1 km

CLA Jetty habitat assessment ● 22


4. DISCUSSION The benthic habitat surrounding the CLA Jetty is typical of the Pilbara region, being sub-

tropical/semi-arid, nearshore tidally driven waters. It is largely characterised by sand and

muddy substrates which are sparsely scattered with hard pavement/rock covered by turf

algae, macro-algae, sponges and lesser amounts of hard and soft coral. Colonies of hard

corals were observed only at Location 1, closest to the shore in shallow waters where light

penetration is greatest. Macroalgae also becomes sparser as depth increases, particularly

beyond Location 7 (>10 m depth).

The depth of the water ranges from approximately 7 m at the southernmost point of the CLA

Jetty, to 13 m at the deepest proposed pile location (Location 9). Furthermore, the

distribution of relative hardness and roughness surrounding the Jetty reflects the dominant

habitat type of bare sand and mud.

Overall, macro-benthic habitats in the vicinity of the CLA Jetty are typical of the wider area,

hence the piling works are unlikely to pose a significant threat to the communities present.

Impacts associated with jack-up barges are considered likely to be insignificant on a wide

habitat scale given the relatively small footprint of the barge legs and the patchy/localised

nature of benthic primary producer habitat in the area.

S T R E E T P O S T A L C O N T A C T

25 Southport Street


WESTERN AUSTRALIA

PO Box 1034


WESTERN AUSTRALIA

+61 (0)8 6218 0900 P

[email protected]

A B N 68 120 964 650 www.hydrobiology.biz

Documents

CLA JETTY HABITAT ASSESSMENT - epa.wa.gov.au · CLA Jetty Habitat Assessment p. iv Rio Tinto EXECUTIVE SUMMARY The benthic habitats at nine locations along the Cape Lambert (CLA)