Part 1 of 2

Victorian National Parks Association Inc.

Level 3, 60 Leicester Street Carlton Vic 3053,

Tel: (03) 9347 5188, Fax: (03) 9347 5199

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Submission on the Supplementary Environment Effects Statement for the proposed Channel Deepening project in Port Phillip Bay

Prepared by Jenny Barnett May 2007



The VNPA strongly opposes this project because the Bay’s assets are too precious and the risks too high.  The very many risks are cumulative so the chances of something going seriously wrong are great.  The multiple possible impacts on a large number of areas and environments, and the unpredictable interactions in the system, make for many uncertainties and a strong possibility that unforeseen (or even foreseen) disasters will occur.  The risk is not worth it to allow a relative minority of larger ships into the Bay with limited economical benefits to the general public.  Alternatives such as use of other ports for larger ships, encouragement of use of the Melbourne Port by medium sized ships and improvement of the National rail network are far preferable to taking this risk.




The provision of only 6 weeks to digest and analyse 15,000 pages of documents containing complex technical information suggests that the government does not seriously wish to have the project scrutinised.  With the level of resources available to us, and the multiple demands on our staff and volunteers, we have been unable to examine the documents to anywhere near the extent that that we feel is necessary to respond to such a significant proposal.  If there are errors or omissions in our submission because we have missed some aspect in the documents we make no apologies because of the sheer size of the material. Instead we reserve the right to add to our submission at the panel hearing on any relevant matter.


The proposal to have the Panel Hearing very shortly after the submission deadline further exacerbates this situation.  Even more alarming is the proposal to limit the questioning of witnesses and to limit the length of the panel hearings to only 4-7 weeks. As the Panel is itself only given a few weeks to produce a report then this will make the situation even worse.  All this makes it impossible to examine this complex proposal to the depth required. In addition, unfortunately none of the Panel members have had the benefit of sitting through the details of the previous EES, making their task even more difficult. 


Compounding the situation are the limitations placed on the panel preventing them from considering any alternatives to the proposal (such as other ports or transport options) or the cumulative effect of the maintenance dredging that will follow indefinitely.


Proper analysis by the public, independent experts, and the Panel cannot be done quickly.  The long-term impact of all aspects of the proposal and whether there are other means to achieve the same end are vital considerations.  Our Bay is a vital asset to our State and deserves better.



The Bay is too precious

As outlined in the EES and the SEES, the Bay has a vast array of important values including high biological diversity, complex ecosystems, Marine National Parks and Sanctuaries, internationally listed wetlands and sites of archeological and geomorphological significance. A large number of species in the bay are endemic to the region and most of the Bay’s species are found in the southern half of the bay where extensive dredging and dumping of the material is to take place.  There are threatened species such as sea-horses, snapping shrimp, ghost shrimp, giant seaweeds and unique ‘sponge gardens’ in the Rip. Thirty-three species are known to be ‘of conservation concern’ with much still unknown about the vast majority of species in the Bay. There are seals, dolphins, penguins and occasionally whales.  There are also important uses including a wide range of recreational and tourism activities, fishing industries, aquaculture and other marine-based industries.


The Bay also acts to help de-nitrify the runoff and treated sewage that is discharged into the Bay in large quantities. The sensitive benthic ecosystem is critical in this respect and irreversible damage of its ecosystems has been suggested as a possible outcome.   It is also possible that seagrass losses will be irreversible with long-term impacts on fisheries and the overall ecology of the Bay.   No matter how remote this possibility, it is a chance we should not be taking


The Bay is also of great economic importance for a wide range of reasons including ecological services (such as de-nitrification), fish resources, tourism, recreational and so-on.  The economic value of these, if put at risk, would far exceed claimed economic benefits of the proposal, and are also enjoyed far a far wider range of the general public.



Many impacts are certain or likely


The proposed dredging program is massive on a world scale and long in duration.  As outlined during the 2004 EES hearings it is four times the size of the next largest dredging operation anywhere.  It will affect large areas in the north and south of the Bay.  Port Phillip is the largest enclosed bay in the world, with complex and unique marine ecology.  It is no wonder that assessment of the proposal is complex and the project controversial.


The sheer volume of material to be removed (about 25 million m3 initially and 17 million m3 for maintenance in the next 30 years), and the multiple and difficult to control problems associated with moving it, mean some impact is inevitable.  The SEES admits this but claims such impacts will be ‘short-term’ or ‘limited’ with most impacts lasting only 1-2 years. Where, after 100 years of dredging in the Bay (at a much lesser scale), are the comprehensive studies of the impacts of past dredging that provide the basis for these risk assessments?  The physical change to the Bay will also mean some permanent changes in the Bay’s physical environment which again are described as ‘limited’.


Impacts which particularly concern the VNPA include:

  • Impacts on shorter-lived fish, especially those living near or passing through the mouth of the Yarra and/or with migration patterns in and out of the bay

  • Impacts on penguins at St Kilda

  • Impacts in the wider bay on penguins, seabirds, dolphins and seals due to turbidity affecting their feeding because of poor visibility and/or reduction in prey numbers.Risk of toxic algal blooms in the north of the Bay

  • Permanent loss of sea-grass in the south east of the Bay

  • Rockfalls in the Entrance resulting in loss of slow growing biota and damage in the Marine National Park

  • Turbidity and sedimentation and their myriad and wide reaching effects

  • Disturbance and mobilisation of contaminated material in the north of the Bay.

  • Accumulation of contaminants in top-order carnivores such as larger fish, seals and penguins

  • Mobilisation of nutrients and algal cysts - including the possibility of upsetting denitrification processes when combined with turbidity and sedimentation

  • Changed currents, - effects on transport of larval fish

  • Underwater noise and vibration and its effects on migrating fish and penguins

  • Changed tidal ranges, currents and wave patterns - potential impacts on salt marshes and areas such as Mud Island

  • Risk of larger oil spills- with potential wide ranging impacts.

These impacts are outlined below.  To match the layout of the SEES, issues are largely dealt with area by area except where some issues overlap.


Some of these impacts and risks on their own may seem ‘minor’ or ‘medium’ (but see comment on risk analysis below). However, taken in total, and especially if all does not go as predicted, there is a cumulative risk of some serious losses in the medium or long-term, especially if the system is periodically re-disturbed with not-so-small maintenance dredging.


In addition, some possible scenarios such as oil spills and widespread denitrification and algal blooms could result in catastrophic outcomes.  While these may be unlikely, they nonetheless represent a real gamble.



Bias In The Risk Analysis


The risk analysis employed, and the SEES in general, play down the risk to the environment. Different standards and criteria are applied to economic considerations than to the environment and social considerations.  If the shipping industry suffers more than one month’s stoppage this is rated as an ‘extreme’ consequence (p5-54) and as ‘moderate’ when it is for only one week. 


In contrast, for the various aspects of the environment and tourism permanent loss is required to get an extreme rating and effects that last for years are only rated as ‘moderate’.  Over 10 fatalities or major health impacts on over 1000 individuals are required to be assessed as ‘extreme’ while 1 fatality and/or 100 persons suffering major illnesses or injuries is considered ‘moderate’.





Ninety percent of the river bed in the Yarra for 6 km from the mouth, up to (and including) Appleton Dock, will be removed (3.37 million m3) together with 5% of the seabed in Hobsons Bay (2 million m3).  Impacts will include gross removal of habitat, increased turbidity, re-suspension of contaminants, noise and vibration and possible stimulation of algal blooms.


Recovery of various invertebrate and microscopic biota in the river and seabed will take up to one year, if the SEES is correct in its predictions.  Fish and other fauna dependant on these such as Black Bream will be affected for at least this period.


Seahorses and pipefish


The SEES notes that a number of EPBC protected seahorses, seadragons and pipefish (syngnathids) are found in seagrass and reef algal habitat in Hobsons Bay and some are in the Yarra River estuary (p12-30 – 12-35).  Twenty-four species are found on the wider Bay, however, the SEES main report is vague about numbers of species in each area.  Impacts from turbidity and high noise percussion are dismissed as ‘minor’ on the grounds that the various species are found elsewhere in the Bay or Australia.  Australia has about a third of the world’s syngnathid species with this group being sparse or absent in many other parts of the world.  Protection of our exceptionally diverse fauna is important even if individual species are found elsewhere.


Fish in the Yarra


Estuaries are usually more diverse than rivers. In addition to the above syngnathids, the lower Yarra has records of 32 native species between East Melbourne and the mouth (see table below) including at least 10 species of freshwater fish from further up the Yarra that are diandromous, (species that pass between freshwater to marine/estuarine systems and back, in either direction, as part of their lifecycle).  They include 4 species of gallaxids, one of which is the Mudfish.  There are also five mainly freshwater species that frequent lower stretches, 3 species that frequent both freshwater and estuaries, 8 species confined largely to estuaries, and 6 largely marine species.  These were detailed in one of our earlier submission to the 2004 EES.  But, in spite of our provision of this information, the SEES ignores the overall fish diversity and only considers those fish that are listed as threatened, or are of commercial value.


In spite of this diversity, there has never been a fish survey between Melbourne and the sea save for one day with gill nets (at Spencer St Bridge, Victoria dock, Westgate Bridge, Newport power station) plus one dip net near Newport power station.  In contrast Dights Falls in Kew has been intensely surveyed.  Most lower Yarra fish records are either opportunistic or are very old, dating back to the 19th century.  For those fish with only old records, it should not be concluded they are no longer there, especially smaller non-commercial/recreational fishing species.  For instance, the single dip net survey at Newport in 1989 revealed the only record for the Bridled Goby and only the second record for the Blue-Spot Goby (previously recorded in 1935).


We are disappointed that the SEES has still not conducted base-line surveys for the smaller fish such as the gobies, gudgeons, hardyheads and smelt in the lower Yarra, although at least the invertebrates have now undergone some limited sampling.


Native Fish in the lower Yarra*



#Grayling, Tupong, Spotted Gallaxid, Broad-finned Gallaxid, Common Gallaxid, #Mud fish, Short-finned Eel, Short-headed Lamprey, Pouched Lamprey, Australian Bass.



#Macquarie Perch, #Trout Cod, #Murray Cod, Golden Perch, River Blackfish.



#Yarra Pigmy Perch, Australian Smelt, Flat-headed Gudgeon.



Blue spot goby, Bridled goby, Tamar River Goby, Small-mouthed Hardyhead, Black Bream, Estuary Perch, Yellow-eyed Mullet, Mulloway.



Sea Mullet, Sand Flathead, Australian Salmon, Green-back Flounder, White Trevally, Southern Anchovy.



* This does not include syngnathids which are additional. About another 7 strictly freshwater native fish species are further up the Yarra and are unlikely to be affected and there are also at least 8 exotic species (some of which occur near the mouth).
# = species listed under EPBC and/or F&F
Guarantee Acts

Most impact would be on species that are entirely estuarine or spawn in or migrate through the estuary - especially as sensitive larval forms. Bottom dwelling and burrowing fish are also highly vulnerable as their habitat is to be removed in large quantities. At least half of the 32 species are likely to be affected in this way. Less affected species would be those that can live for their whole life cycle in a range of habitats or are mainly marine or freshwater. Some species have a degree of tolerance to turbidity and low dissolved oxygen (perhaps a prerequisite to living in the Yarra!). But whether they could survive the greatly increased turbidity of intensive dredging and, in the case of burrowing fish, the gross disturbance and removal of the substrate, is another question.

It is important to note that a significant part of the fish fauna in the upper Yarra, including in the National Parks surrounding Melbourne, depend on the young and/or spawning adults of the diandromous species surviving in this lower river section. We strongly suggest that, should dredging proceed, that monitoring be undertaken of the more common diandromous species in the middle and upper Yarra and at Dight’s Falls. perhaps as part of Melbourne Water’s on-going programs .

The avoidance of dredging in the Yarra in spring, that is proposed to lessen the impact on grayling and mudfish, should also be of some benefit to most of the other diandromous species as the migration time of young fish up the river is similar for most of these species. However unfortunately the dredging in autumn-winter in Hobsons Bay could well affect fish larvae (of both endangered and more common species) coming down at this time as relatively high turbidity will result near the mouth of the Yarra (see Fig 10-16 p 10-75). Young fish larvae may be sensitive to such pollution, as is acknowledged in the SEES (p12-36, 12-37).

For grayling and mudfish (and hence the other small migratory fish) the SEES admits that population of juveniles reaching breeding age may be reduced for one year (p12-35). But the SEES then claims that for grayling ‘given the 2-3 year breeding span of the species, recovery is therefore expected within 1 to 2 years’ (p12-36). However this statement is misleading and incorrect as is the information about grayling on p 12-29 which incorrectly implies all grayling ‘can breed from one year’. In fact, while some grayling males can breed at one year, females do not do breed until the second year and 88% of breeding grayling then die (Koehn and O’Conner 19901 , Cadawaller and Backhouse 19832 ). Most survivors do not last beyond the third year. Thus most females have only one chance to breed. Therefore the failure of one, or worse two years in a row, breeding season will have a serious effect on populations.

1 Koehn and O,Conner 1990: Biological Information for Management of Native Fish in Victoria.  Freshwater Fish Management Branch, Arthur Rylah Institute for Environmental Research, Department of Conservation and Environment
2 Cadwallader and Backhouse 1983:  A Guide to the Freshwater Fish of Victoria.  Fisheries and Wildlife Division, Ministry for Conservation

Mudfish and other gallaxids in the Yarra are even more short-lived. These generally only live up to two years and have only one or more rarely two chances of breeding and are therefore susceptible to the dredging which spans just over year.

All these species could also be affected by turbidity affecting their migration within the Bay (p12-37). This can also be affected by changed currents. Permanent changes in the currents in the Bay resulting from the deepened channels could result in the larvae of fish being unable to return to the very north of the Bay and the mouth of the Yarra. At the 2004 panel hearing it was reported by Greg Jenkins that changes in the currents from the deepened channels could result in the larvae of King George Whiting being unable to reach the very north of the bay. While this may be insignificant for the whiting which settle over a wide area, it may be far more significant other young fish such as those that enter the mouth of the Yarra as part of their life cycle.

This particular effect is important as it represents a permanent change to the Bay environment as opposed to the more temporary effects of turbidity etc. As stated by Mr. Jenkins “in terms of larval transport, if channel deepening results in marked changes to transport patterns that result in larvae not reaching important juvenile habitat then there would be significant long-term impact.” (Witness statement p5). In the Heads, turbidity and impacts from noise could also be an additional problem for those Yarra River species that migrate right out to sea and back.

As admitted in the SEES (p12-38) one year of poor recruitment could affect population viability of already endangered species. It would also impact severely on other more common species as the dredging spans over two autumns and in the longer term, permanent current changes could have unforeseen lasting impacts on populations.

Other Fish

The SEES admits that the sensitivity of local Bay fish species to various levels of suspended sediments has not been determined (p12-36). A ‘medium risk’ of damage to fish larvae and juvenile fish is then predicted. It is far more truthful to say the risk is unknown.

Dredging in Hobsons Bay could affect a significant proportion part of the anchovy spawning there. Research by Primary Industry Research Victoria (p1 Annexure C2 – Anchovy, Part C POMC submission to 2004 panel hearing) indicated that spawning of this species is highest in Hobsons Bay. Fish larvae including anchovy and Black Bream are likely to be affected in at least the short-term with flow on implications for species dependant on them. In drawing the conclusion of a ‘medium risk’, the SEES has undertaken only a literature review. There has been no experimental work to look at the effects of turbidity on these and other fish eggs and larvae, and its conclusions could well underestimate the impact.

The SEES notes that Commercial Fishing may be affected for 1-2 years after the completion of the project (P 12-88). Considering the duration of the project, this could be a total of at least 2-3 years (or longer if its speculations are incorrect).


Effects on penguins of possible reduction of anchovy and other fish due to dredging are portrayed as ‘minor’. We dispute this and believe that combined with other factors such as toxic algal blooms the risk, especially to the St Kilda Penguins, is far more substantial.

Dredging in the Yarra River, Williamstown and Port Melbourne Channel occurs during the penguin breeding season and also during the spawning period of anchovies which comprise over 90% of the penguins’ diet. Increased turbidity is also admitted by the SEES to possibly affect the penguins’ ability to see and catch their prey. In addition, dredging in the warmer months is when algal blooms resulting from the stirred up sediments are most likely.

The SEES dismisses possible effects of the toxic blooms and food shortages in the area because ‘most penguins are feeding in other parts of the Bay’. However we understand that recent research, which will be outlined in the Earthcare submission, has found St Kilda penguins foraging in areas that differ from those identified in the SEES. Distribution data for penguins underpins the entire SEES assessment, therefore the SEES assessment of a "minor" effect on penguins is incorrect and must be reviewed.

In addition, even if the penguins do forage elsewhere, they must swim back to their colony and cross any algal blooms in the vicinity. In attempting to counter this possibility, the SEES states that “since algal blooms occur naturally from time to time, any effect could be considered within the tolerance levels of the penguin” (p13-107) and that “given the uncertainties surrounding the occurrence, extent, duration and toxicity of algal blooms, the potential effects on penguins have been assessed as low risk”. These are assertions that cannot be made. If the intensity and frequency of blooms resulting from dredging exceed the ‘natural’ levels experienced to date, the impact on the penguins may not be within their ‘tolerance levels’. In fact the level of risk, specifically to the St Kilda penguins, is largely unknown.

The St Kilda colony of penguins is already under stress from the drought. The lack of good flows of fresh water from the Yarra has meant no anchovy spawning and poor breeding success over the last year. We understand that the population has dropped by an estimated 20%. This is without channel deepening, which will compound the problem if it closely follows drought.

Lastly, the penguins in this area and elsewhere in the Bay would be especially susceptible to any oil spills. The allowing of larger ships potentially increases the size of any disaster with catastrophic effects (see also below).