Environmental Talking Points

VARS answers your environmental concerns

An old wreck dive site in Victoria, Australia
Old wreck dive site in Victoria
© Mary Malloy & Alan Beckhurst

The following talking points are provided to assist in discussions with individuals or groups concerned about the environmental impact of sinking the HMAS Canberra as an artificial reef. These are presented as a series of Frequently Asked Questions (FAQs).

Q. Isn't the deliberate sinking of a ship just an act of environmental vandalism? Wouldn't it be better to recycle the scrap metal and so benefit the environment?
A. If done properly, the deliberate sinking actually creates an artificial reef which has a significant positive impact on the environment. Obsolete ships that are tied to a pier or anchored in some forgotten bay are considered environmental liabilities. The artificial reefing process safely turns these unwanted ships into wonderful assets for coastal communities. Attempting to recover the scrap metal is a very expensive and often quite impractical proposition that may, on balance, be more damaging to the environment through issues such as high energy consumption and unusable scrap portions.
Wreck diver in the temperate waters of Victoria, Austrlalia
Wreck diver in Victoria, Australia
© Mary Malloy & Alan Beckhurst
Q. What are the positive effects on the environment?
A. Properly established and managed artificial reefs rapidly attract a huge variety of marine organisms and become fully functioning ecosystems within a short period of time. Such sites can help natural marine species to recover from deleterious human effects as well as enhance fish populations by acting as nurseries. The sites are also wonderful ecotourism opportunities that are highly regarded as dive destinations throughout the world. As such they provide educational opportunities and spark increased interest in the underwater environment. Further, they provide fantastic opportunities for research into the establishment of reef ecosystems.
Q. Isn't it true that artificial reefs simply act as aggregating devices that attract and concentrate fish making them easier to exploit and more vulnerable to over-fishing?
A. There is insufficient scientific data to establish this point of view as a fact. Some studies have pointed to this as a potential problem. However, there are other studies that support the view that the new reef acts as a nursery for fish populations and enhances the density of viable fishing species within an area. More recent studies on artificial reefs where fishing has been prohibited strongly support this view. The best management approach is to regulate the artificial reef as a "no-take" zone thus avoiding any possibility of over-fishing and increasing the likelihood of the site becoming a nursery that enhances fish populations for the benefits of commercial and sport fishermen in the surrounding areas.
Encrusted structure of a shipwreck in Victoria, Australia
Encrusted shipwreck in Victoria
© Mary Malloy & Alan Beckhurst
Q. What about the environmental impact from the hazardous materials on the ship — such as asbestos, PCBs, oils, etc?
A. The primary concern is that our new artificial reef is protective of the public health and the environment. Prior to sinking, the ship will be thoroughly decontaminated and subject to a rigid inspection by appropriate authorities. The project will be managed in a professional manner with supervision by people who have considerable expertise in preparing ships as artificial reefs. There is considerable experience gained from around the world with projects of this nature and we can be absolutely sure that there will be no environmental damage from materials that should not be left on board. Interestingly enough, ships have been a part of the underwater landscape for thousands of years. Since the advent of civilization hundreds of thousands of ships have sunk to the bottom of the world's oceans for many different reasons. Most of these ships were not cleaned of any of the fuel, oil or cargo that they contained as they went down. Despite this, many of these ships have become magical underwater ecosystems. With a professional and carefully supervised approach to preparing the Canberra, we can be assured of this.
Q. What about the impact on the existing site? Aren't we likely to crush existing reef or destroy sensitive natural seagrasses?
A. It is important that the final site be chosen to minimise any impact on the existing environment. This is a high priority amongst the criteria used to evaluate any potential site. The best site is one with a sandy bottom, free of existing reef and natural seagrasses. Fortunately, the vast majority of the ocean floor is like this. We are provided with significant guidance from the Department of Sustainability and Environment who have worked on this project from the outset to ensure that environmental considerations are safeguarded at all times.

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