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Science
5 August 2005
Careel Bay Pittwater Protection Association Inc.
Dear Re: Review of EIS for proposed Careel Bay Marina This letter of advice has been prepared to assist the Careel Bay Pittwater Protection Association ('the Association') to draft submissions to a development application No. DA-144-6-2005-i (the 'DA') submitted by Austral Monsoon Industries Pty Ltd for the upgrade and expansion of the Careel Bay Marina located at Lot 1 DP 1033779 and Lot 254 DP 752046, 94 and 94A George Street, Avalon ('proposal'). We understand the DA was lodged on 10 June 2005. In preparing this advice we have reviewed an Environmental Impact Statement titled Careel Bay Marina Development Environmental Impact Statement, prepared by Patterson Britton & Partners Pty Ltd, dated June 2005 ('EIS'). We have principally focused our review on identifying deficiencies in the EIS for the purposes of providing arguments to the Careel Bay residents that may be useful in drafting submissions to the proposal, which we understand are due by 12 August 2005. SUMMARY OF PROPOSAL The proposal comprises the redevelopment of existing boating facilities (wharf, handstand area etc) and the construction of a floating marina and maintenance of a navigation channel. Stage 1 (p E-1):
Stage 2 (p E-2):
We note that fill will be used to raise the ground surface of the existing car park and slipway area (no fill is to be placed below Mean High Water Mark) (p 96); and no dredging is proposed (p 96). LIMITATIONS This review focused on the potential impacts of the proposal on the natural environment, and in particular, the potential impacts on aquatic habitats and water quality. This review has not addressed the potential amenity impacts of the proposal (such as noise impacts and visual impacts) or potential impacts in relation to traffic. These are potentially significant issues, particular in consideration of the high amenity of the local area. We leave it to the residents to make their own arguments regarding potential amenity and traffic impacts of the proposal in submissions in objection to this proposal. LEGAL ADVICE [CONFIDENTIAL] SUMMARY OF ENVIRONMENTAL IMPACTS Careel Bay, and in particular the area adjacent and to the east of the proposal site, is of very high conservation value. The bay contains the most extensive seagrass beds in Pittwater as well as a mangrove-saltmarsh complex, which comprises the largest stand of mangroves and one of only a few patches of saltmarsh in Pittwater (Pittwater Council 2005). [1] Seagrass beds within the bay comprise Posidonia australis, Zostera capricorni and Halophila sp. with Posidonia occurring immediately adjacent to the proposal site. Posidonia is particularly subject to disturbance and is relatively restricted in NSW (NSW Fisheries 1997). [2] The mangrove-saltmarsh complex and sand and mud flats occur within approximately 400 - 500m to the north and east of the proposal site, and contain important habitat for birds, particularly fishing and wading birds (EIS Appendix E pp 13-14). Migratory wading birds subject to the Japan-Australia Migratory Bird Agreement and China-Australia Migratory Bird Agreement are known to utilise this area (Pittwater Council 2005). In addition, a breeding pair of the threatened species Bush Stone-Curlew (listed as endangered under the Threatened Species Conservation Act 1995 ) (TSC Act) is resident within the bay and has been recorded at the foreshore along the eastern side of the bay (EIS Appendix E p 16). The foreshore area also provides potential habitat for the threatened Water Rat ( Hydromys chrysogaster ) (listed under the TSC Act) (EIS Appendix E p 14). It is widely recognised that marinas can significantly affect the aquatic environment, particularly due to water pollution and direct and indirect impacts on aquatic habitats such as seagrass beds (South Australia Environment Protection Authority 2005 p 1). [3] It is recognised that this proposal has the potential to improve the water quality of the local area and potentially reduce direct impacts on seagrass beds due to the following: Proposed water quality controls to be implemented during operation of the proposed marina. The opportunity to remove up to approximately 25 swing moorings that are currently located in seagrass beds. However, the potential environmental benefits of the proposal must be balanced against other potentially significant impacts of the proposal on the high conservation value of the adjacent area, and the possibility that environmental objectives could be achieved by feasible alternatives to the proposal. The key potential environmental impacts of the proposal on aquatic habitats and water quality are: Significant potential to spread the noxious marine vegetation Caulerpa taxifolia and associated potential impacts on seagrass beds. Piling activities during construction and associated potential impacts on water quality. Significant increases in boat activity, comprising larger boats (EIS p 138), and likely comprising large powerboats, in shallow waters, and associated potential impacts on water quality and seagrass beds. Significant increases in boat maintenance activity, and associated potential impacts on water quality and seagrass beds. Impacts of shading on seagrass beds. Potential cumulative impacts of the proposal associated with the possibility that no swing moorings would be relocated from seagrass beds and the potential total increase in the number of permanent moorings in Careel Bay. ALTERNATIVES TO THE PROPOSAL The EIS has not adequately considered feasible alternatives to the proposal. The Environmental Planning and Assessment Regulation 2000 (EP&A Regulation) requires an analysis of any feasible alternatives to the carrying out of a development, having regard to its objectives, including the consequences of not carrying out the development. A primary justification of the proposal is that the existing boating facilities would likely have to cease to operate within a few years due to improved environmental and occupational health and safety requirements (EIS p E-7). Two primary objectives of the proposal are: To provide boat repair and maintenance facilities to meet community demand, incorporating environmental controls which are world best-practice and which meet the requirements of the Protection of the Environment Operations Act 1997. To provide an opportunity for the removal of swing moorings from the seagrass area, by consolidation of 37 existing commercial swing moorings onto a 37 berth floating marina occupying a smaller total waterway area. The EIS has only considered alternatives to the proposal within a very limited scope. Alternatives have only been considered in relation to components of the current proposal (for example, use of floating versus fixed marina berths, or the layout of the marina berths) (EIS pp 49-51) and no consideration has been given to alternatives outside this framework. For example, the EIS has not considered (and justified any subsequent decision) whether it would be feasible to meet water quality objectives by redeveloping the marina within the existing development envelope or whether the existing 25 moorings within the seagrass beds could be relocated without the need to provide for a 37 berth floating marina. It is considered that such alternatives may be feasible (recognizing that the term 'feasible' includes consideration of financial costs) and must be considered. SIGNFICANT POTENTIAL TO SPREAD CAULERPA TAXIFOLIA The EIS has identified that the noxious marine vegetation Caulerpa taxifolia occurs within the vicinity of the proposal site (EIS p 80) and '.sporadically throughout the seagrass distribution within Careel Bay ' (EIS Appendix E). The proposal has a significant potential to spread C. taxifolia. The EIS has not adequately addressed this significant issue. C. taxifolia is listed as noxious marine vegetation Class 1 (representing the highest level of threat posed to the aquatic environment) under the Fisheries Management Act 1994 (FM Act). NSW Fisheries has recently (6 June 2005) declared a fishing closure within Careel Bay due to the occurrence of C. taxifolia (including within the area of the proposal site) [4] and has established 'no anchoring' areas at the location of the infestation (NSW Fisheries 2004 p 9).[5] Little is known about the impact of C. taxifolia on native biota in NSW estuaries, although a large number of studies are currently underway (NSW Fisheries 2004 p 18). However, based on evidence from overseas as well as local anecdotal evidence, it is believed that C. taxifolia has the potential to significantly impact native biota, including seagrasses. This is due primarily to its ability to grow extremely quickly and out-compete and smother native flora and its production of toxic substances that deter epiphytes and herbivores and may also adversely effect nearby flora ( Creese et al. 2004 Ch 3;[6] NSW Fisheries p 5). NSW Fisheries is particularly concerned about the impacts of C. taxifolia on the seagrass Posidonia australis, and has identified protection of this species from invasion as a high priority (NSW Fisheries 2004 p 16). C. taxifolia reproduces, disperses and establishes new infestations primary by fragmentation of individual plants and subsequent attachment and re-growth in new areas (Creese et al. 2004 Ch 4). C. taxifolia is very easily spread by human-induced and natural mechanisms, including boat propellers, boat hulls, boat trailers and anchors and anchor chains, wind and wave action (in particular, strong winds and storms), and currents and strong tides (NSW Fisheries 2004 pp 5-8; Creese et al. 2004 Ch 3). It has been demonstrated that one single small fragment may settle and develop root-like structures and establish a new infestation ( NSW Fisheries 2004 p 4-5; Creese et al. 2004, Ch 3). Recent scientific experiments have indicated that C. taxifolia fragments may survive short periods of desiccation, which would allow them to be transported overland to new sites within an estuary or to new sites in nearby estuaries (Creese et al. 2004 Ch 4). High levels of boat activity have a significant potential to spread C. taxifolia by disturbance of the estuary bed and associated fragmentation of individual plants (NSW Fisheries 2004 p 16). This has been demonstrated by two recent scientific experiments at Lake Conjola (NSW), which examined, using statistical analysis, whether the movement of boats creates fragments of C. taxifolia (Creese et al. 2004, Ch 4). Both experiments involved a small motorboat and dense C. taxifolia beds at two depths: <1m and at 1.5m. In the first experiment (depth <1m), the abundance and biomass of fragments were on average higher in areas with boat activity, with the abundance of fragments increasing by 10 fold and the biomass of fragments increasing by 4 fold. In the second experiment (depth at 1.5 m), there were again significant increases in biomass of C. taxifolia fragments at both depths from before to after boating activity compared to the controls. These experiments indicate that boat movements are likely to significantly increase fragments of C. taxifolia at various depths (at least to 1.5 m), which is likely to result in the spread of C. taxifolia. The EIS has not accurately identified the current location of C. taxifolia in the vicinity of the proposal and has not identified the depth of this occurrence. It only identified generally that C. taxifolia occurs in shallow water to the west of the existing boating facility (using mapping undertaken in May 2002) and that the infestation appears to have spread east to the existing public wharf since that time (EIS p 80). The latest available mapping of the occurrence of C. taxifolia in Careel Bay is provided by NSW Fisheries (August 2004). [7] This map indicates that C. taxifolia has spread since May 2002 and it appears that it now occurs very near to, or underneath, the north-west section of the proposed floating marina and within the navigation channel at the entrance to the floating marina. The infestation in this area occurs at a depth of between 1-4m (Creese et al. 2004). It is important to note that the coverage of an infestation is likely to be significantly greater during the summer (coverage has been shown to increase by a factor of 10 in a single summer), as this is the period where growth is most rapid (NSW Fisheries 2004 p 5). Consequently, the area of infestation identified in August 2004 may be considerably larger at other times of the year. In relation to construction impacts of the proposal, the EIS has only assessed in very general terms the potential impacts of the proposal in relation to C. taxifolia (EIS p 117). The only mitigation measure proposed in relation to C. taxifolia is that its distribution in the vicinity of the proposal site would be reconfirmed prior to the commencement of work, and the infestation would be dealt with in accordance with NSW Fisheries Caulerpa Control Plan if the infestation is found to be within 50m of the construction area. It is not clear on what basis this 50m 'buffer zone' is determined. In any case, based on the most recent mapping of the occurrence (August 2004), it appears that C. taxifolia now occurs in the area within which substantial piling activities would occur. It is likely that piling would cause significant fragmentation of individual plants and may therefore cause significant spread of the infestation to nearby areas or within other areas of Careel Bay (depending on factors such as currents and wind etc). It is important to note that NSW Fisheries has identified in the Caulerpa Control Plan that no single method of eradication has yet been successful and that current methods may be costly, may increase the risk of fragmentation, and may cause unintended direct impacts on native biota (NSW Fisheries 2004 p 13). In relation to the operational impacts of the proposal, the EIS has not assessed the potential impacts in relation to C. taxifolia. It is considered that these impacts are potentially significant. The proposal would result in significant increases in boat activity, comprising larger boats (EIS p 138), and likely comprising large powerboats, within the vicinity of the C. taxifolia occurrence. As indicated above, this has a significant potential to cause fragmentation of individual plants, particularly as the occurrence of C. taxifolia in this area occurs at relatively shallow depths (1-4m). Crease et al. (2004 Ch 4) has specifically identified that activities such as building or maintenance of foreshore structures such as wharves, jetties or boat ramps and the deployment of channel markers can be significant in generating and spreading fragments of C. taxifolia. In addition, the EIS has identified that the operation of the proposal would have a localized effect on water movement due to wind action, resulting in a '.more circulatory flow pattern.' (EIS p 104). The EIS has only generally identified the magnitude and significance of such a change, and consequently, the affect of such changes on fragmentation and dispersal of C. taxifolia is unclear. However, as identified above, wind and currents, particularly during storms, play a significant role in fragmentation and dispersal of C. taxifolia (Crease et al. 2004 Ch 4). WATER QUALITY IMPACTS The proposal is likely to result in significantly increased turbidity of the water column during construction, and despite the proposed water quality controls to be implemented during operation of the proposal, it is considered that some level of water pollution will occur. The EIS has identified that considerable piling activities would be undertaken for construction of the proposal: about 124 piles would be required for Stage 1 and about 37 would be required for Stage 2 (EIS p 42). Piling would disturb sandy to muddy substrates (EIS p 79) and is likely to cause significant turbidity of the water column, which may impact nearby seagrass beds due to a reduction in light availability and smothering. The EIS has stated that a turbidity curtain would be placed around piling activities during Stage 1 of construction, in accordance with the Silt and Sediment Control Plan (EIS p 105; EIS Appendix V). However, there is no proposal to use a turbidity curtain for the 37 piles to be established during the Stage 2 works (EIS Appendix V). It is considered that piling during State 2 is likely to cause significant turbidity of the water column and associated impacts on seagrass beds, which occur immediately adjacent to these activities. In any case, it is also important to note generally that sediment control measures require significant maintenance and consequently are frequently limited in their effectiveness (NSW Environment Protection Authority 2005). [8] Despite the proposed water quality controls, it is considered that the operation of the proposal will result in some level of water pollution, which over the medium to long term may impact on the high conservation value of Careel Bay. Clearly, the ability of the water quality controls to prevent water pollution will depend on proper operation and maintenance (Great Barrier Reef Marine Park Authority 1994 p 77). The first flush system will not prevent all pollutants from entering Careel Bay. The first 10mm of water that washes off contaminated areas of proposed marina would be treated, which contains the majority of pollutants. However, any additional water and associated pollutants will enter the bay (EIS p 22). The most frequently reported water pollution due to the operation of marinas is fuel and oil (South Australia Environment Protection Authority 2004 p 34). Despite water quality controls, marinas have resulted in fuel and oil, as well as other pollutants, entering the water column. This is due to leaking engines, use of oils and lubricants on-deck, spills from vessels and refuelling and disposal facilities, cleaning of vessel decks, in-water hull cleaning and flaking of anti-fouling paints (South Australia Environment Protection Authority 2004). While this would also occur to some extent in the existing situation, the proposed marina would concentrate a large number of boats in a small area that is likely to be less flushed than the open section of Careel Bay, where most boats are currently moored. Contaminants may become highly concentrated in low-flow areas, which may result in significant effects on native biota (pers. comm. 19 July 2005). The improvement in water quality controls compared to the existing situation must be balanced against the significantly increased amount of maintenance activities that would be undertaken at the proposed marina. The capacity of boat maintenance will increase from an existing maximum of 4 boats at any one time to 'an average of about 5 to 7 vessels at any one time' (EIS p 15). Boat maintenance activities (such as abrasive blasting and spray painting) have a significant potential to pollute the surrounding environment. The proposed mitigation measures involve use of mist shrouds '.to minimize the spread of any wash down waters.', undertaking abrasive blasting within tarp enclosures, which '.would be closely monitored on windy days.', and use of vacuum sanders 'where practical.'. (EIS p 107). The EIS is not clear on the effectiveness of these measures, and it appears that they are untested. It is considered that while pollution levels may be minimised, some level of water and air pollution would occur. Air-driven spray guns produce large volumes of overspray drift (Great Barrier Reef Marine Park Authority 1994 p 72). It is important to note that the South Australia Environment Protection Authority (2004) state that vacuum sanders must always be used when undertaking boat maintenance sanding or grinding outdoors or over water (EIS p 39). The proposal would result in significant increases in boat activity, comprising larger boats (EIS p 138), and likely comprising large powerboats, in shallower waters than currently occurs. The EIS indicates that the water depths at the proposed floating marina and entrance to the navigation channel are between about 2.4 and 4.1 m AHD (EIS p 33). Boat manoeuvring and increases in boat activity in shallow waters with sandy to muddy substrates may result in on-going re-suspension of bottom sediments and associated increases in turbidity in the water column. Turbid waters are known to result in impacts on seagrass beds due to a reduction in light availability and smothering. SHADING OF SEAGRASS BEDS The EIS states that the proposal would not potentially shade seagrass beds '.as the marina configuration has been designed to place all structures plus moored vessels over bare soft sediment substratum' (EIS p 118). However, the proposed floating marina would be located immediately adjacent (within 1-2m in some places) and to the west of a large bed of Posidonia australis (EIS Figure 2.2). It is appears likely that parts of the proposed floating marina and some of the boats occupying that marina (particularly the large boats) would result in shading of parts of the adjacent P. australis beds for much of the afternoon. In addition, seagrass beds are highly dynamic and while the current boundaries of the bed appear to be outside the development envelope, this may not be the case in the future, given the appropriate conditions (pers. comm. 19 July 2005). In this regard, it is important to note that the latest seagrass mapping undertaken for the EIS was done in May 2002 (EIS Appendix E p 8), and seagrass bed distribution may have changed since that time. Shading of seagrass beds is known to result in poor health and death of individual plants (NSW Fisheries 2005). [9] To note is that it is NSW Fisheries' policy that applications for new structures (such as jetties or pontoons) over Posidonia seagrass beds will generally not be approved, and that existing moorings within 10 m of seagrass beds may be required to be relocated over time. CUMULATIVE IMPACTS The proposal would result in the relinquishment of 37 commercial moorings (on a 1:1 basis for the 37 floating marina berths) by the proponent (EIS p 127). However, it must be recognised that the proponent cannot guarantee that such an opportunity would be met, because this is a decision for the NSW Maritime Authority (EIS p 128). Consequently, the proposal may result in an additional 37 permanent moorings at Careel Bay and the EIS cannot assert that the proposal '.essentially replaces an existing marina operation hence there are no significant cumulative impacts associated with the proposal' (EIS p 138). It is considered that the relinquishment of the existing moorings by the proponent is likely to result in pressure on NSW Maritime Authority to maintain these moorings. The statement that '.the vessels on the marina berths are likely to be of larger size than the vessels on the commercial swing moorings.' (EIS p 138) indicates that the proponent believes that new vessels (ie from outside Careel Bay ) would occupy the berths. Depending on the extent to which this may occur, then some or all of the existing vessels whose moorings would be relinquished would be required to find new moorings, which would put pressure on the NSW Maritime Authority to maintain the relinquished moorings. It is considered that such a significant increase in permanent moorings and associated increase in boat activity may cause a significant cumulative impact and is not consistent with the high conservation value of Careel Bay. It is also considered that the additional space made available for boats within Careel Bay due to the proposal (which would concentrate boats in a small area) may facilitate an increase in boat moorings within Careel Bay in the future, with associated cumulative impacts. The upper limit cap on moorings in Careel Bay has not yet been met, and is 432 boats (EIS p 128). A primary benefit of the proposal would be the opportunity to relocate approximately 25 swing moorings (5 relinquished commercial moorings and about 20 private moorings) currently located in seagrass beds to areas outside the beds (EIS pp 51 and 128). However, again, it must be recognised that the proponent cannot guarantee that such an opportunity would be met, because this is a decision for the NSW Maritime Authority (EIS p 128). Consequently, it is important to recognise that the proposal may not result in the removal of any swing moorings from seagrass beds. Should no moorings be relocated, the likely additional pressure on seagrass beds due to the proposal is considered to be a potentially significant cumulative impact. OTHER POTENTIAL IMPACTS The seagrass beds and the wharf piles and rock ballast at the existing boat facilities provide potential habitat for a number of seahorse and pipefish species listed as marine species under the Environment Protection and Biodiversity Conservation Act 1999 (EIS Appendix E p 21-22). Indeed, the EIS identifies generally that pipefishes and seahorses are likely to utilize the wharf piles and rock ballast at the existing boat facilities (EIS Appendix E p 23). The EIS indicates that no species were recorded within the vicinity of the proposal site. However, it appears that only a very limited search was undertaken, and only within the vicinity of the existing boat facilities and not within the seagrass beds (EIS Appendix E p 21-22). It is considered that the proposal, and in particular, the removal of the existing boat facilities and the significant potential to spread C. taxifolia, may impact potential and/or likely habitat for these species and consequently any individuals or populations that may occur in the local area. However, the location and size of any such populations are unknown, and consequently, the extent of such an impact is unknown. The proposal will result in increased vehicle and boat activity within the vicinity of the proposal site and associated amenity issues (such as noise, traffic and lighting issues). It is difficult to quantify or quality the potential impacts of this increased activity on the fauna associated with the adjacent area, including migratory birds (known to occur), the threatened Bush Stone-Curlew (known to occur) and Water Rat (may occur). For example, it is known that the Bush-Stone Curlew is attracted to lights (such as streetlights) to forage for insects and that deaths have occurred due to collisions with vehicles (EIS Appendix E). However, it is difficult to determine whether the proposed lighting at the marina would result in impacts on the Bush Stone-Curlew. It is also difficult to determine whether traffic, noise or lighting associated with the marina would disrupt the behaviour of migratory birds. However, it is considered generally that such increased activity has the potential to cause disruptions and/or impacts and is inappropriate adjacent to an area of such high conservation value. Yours sincerely Environmental Defender's Office Ltd
Chris Nunn, Solicitor Footnotes
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