Premier on the Rocks

Last week Mr. Brumby and PoMC called a press conference to talk up the unimportant, irrelevant departure of the Queen of the Netherlands . This week they are silent about new scientific reports of extensive damage to unique sponge gardens at the Entrance. 

Mr. Brumby said channel deepening was an exemplary project in terms of its environmental credentials. He spurned critics of the project, saying “they should have known better”. This week, perhaps it’s Mr. Brumby who should have known better.

See: Dredging damage mocks Premier's praise The Age August 26

Article reproduced in full:

DREDGING has caused environmental damage beyond expectation at the entrance of Port Phillip Bay, with scientists reporting a biological shift in marine communities there.

A week after Premier John Brumby feted the dredging project for its ''exemplary'' environmental performance, a report has shown the impact of loose rock fall at the entrance has been worse than the Port of Melbourne predicted.

The entrance is one of the most environmentally sensitive parts of the bay, boasting a deep canyon that is home to rare and unique reef sponges. Some of the species in the canyon are found nowhere else on Earth, and the canyon's communities were last month listed as ''threatened'' under Victorian law. Fears the communities would be damaged by loose, dredged rock were partially realised yesterday, with rockfall found to have exceeded the Port's predictions at a part of the entrance called Rip Bank.

The excess rock was found to have ''blanketed a considerable portion of the reef'' between 37 and 57 metres underwater, with many large boulders still visible and unstable.

''Rockfall impacts are likely to have been considerably greater than the predictions in the [Port's official environmental projections],'' the report said.

Rockfall was within expectations at other sites around the entrance, but the report still painted a graphic picture: ''There was considerable impact damage from falling rock slabs, including breakage of shelves and overhangs.''

In a significant development, the report said the structure of the ecological community throughout the entire canyon had changed since dredging took place.

One of the major symptoms of this was the changing fortunes of the encrusting ruffled grey sponge, which previously covered between 30 and 60 per cent of the canyon, but was found to be covering only between 10 and 30 per cent.

Large decreases were also reported for other types of sponges and cnidarians.

Rival species appeared to be taking advantage of those declines; the report noted that an unidentified ''grey branching colony'', a sea animal that resembles a sponge, had advanced in significant numbers.

Investigators also noted examples of seaweed flourishing where sponges previously had, which could delay the return of sponge assemblages ''by years''.

The report did not definitively blame dredging for the canyon-wide biological shift, but it noted the changes were observed over the period dredging was taking place, and similar changes did not occur at test sites in nearby Victorian waters.

In a prepared statement, dredging operators at the Port of Melbourne acknowledged the rockfall excess at Rip Bank, but said most results were largely within the project's expectations.

Port officials stressed the causes of the canyon-wide biological shift were unknown, and dredging was one possible cause along with natural causes.

The port vowed to continue monitoring the ecological changes.

Australian Conservation Foundation spokesman Chris Smyth said the report contained ''shocking revelations'' about the impact of dredging at the entrance


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