Issues Magazine

Who Will Protect the Cuttlefish from BHP Billiton and Other Polluters?

By Jochen Kaempf (1) and Dan Monceaux (2)

BHP Billiton has recently received South Australian and federal government pre-approval to pollute Upper Spencer Gulf, one of the most fragile and distinctive marine ecosystems in Australian waters. Is this a sign of gross failure of environmental legislation in Australia, or is technology advanced enough to eliminate natural disasters in this region?

For many years, and against the advice of marine experts, the world’s richest multinational, BHP Billiton, has insisted on constructing a large seawater desalination (“desal”) plant at Point Lowly near Whyalla in the Upper Spencer Gulf in South Australia. This plant will supply up to 280 megalitres per day of desalinated water to the Olympic Dam Mine expansion, deep in South Australia’s arid heart. This new mine will become the largest open-pit mine in the world, offering a trillion dollar bounty of uranium, copper, gold and silver.

Given the high ecological significance of the Upper Spencer Gulf region, BHP Billiton’s choice of location has been a key test of South Australia’s marine environmental legislation. This desal plant is the first glimpse of a series of wider, wholesale industrialisation agenda to support the state’s pending mining boom. Other developments associated include additional desal plants, diesel storage facilities, refineries, and explosives factory and new shipping ports for mineral exports.

When historical examples of industrial pollution around the world are considered, it is not far-fetched to predict that this massive industrialisation will irreversibly destroy the precious marine ecosystem that exists in this region. Do we just watch and wait?

Upper Spencer Gulf is home to the world’s only mass aggregation of the iconic giant Australian cuttlefish (Sepia apama) – a fascinating and beautiful species that has a lifetime of only 1–2 years. Owing to this short lifetime, this cuttlefish species is endemic to the Upper Spencer Gulf and is particularly vulnerable to marine pollution. Every year around June/July, tens of thousands of cuttlefish usually appear along the rocky shore of the Point Lowly Peninsula, where the females attach their eggs to the underside of rocks. This event attracts tourists and scientists from around the world and is truly a natural wonder.

The Upper Spencer Gulf is a unique hot spot for many other marine species in Australian waters. For instance, it is the home of the world’s largest population of western king prawns (Melicertus latisulcatus).

The giant Australian cuttlefish has become a key symbol in the debate on the viability of industrialisation in this region, which is concurrently being considered for marine park classification by the South Australian government. The Upper Spencer Gulf is already home to three marine aquatic reserves, and is likely to become one of 19 planned marine parks in South Australia in 2012.

The distinctive marine ecology of South Australian gulfs, including extensive seagrass beds and mangrove forests, has developed over thousands of years. The main physical reasons that have facilitated the development of this environment are the shelter of the gulfs’ upper reaches and the surrounding arid climate.

First, like other gulfs, South Australian gulfs are largely sheltered from open-ocean storm waves. The colonisation of extensive seagrass beds, for instance, would have been impossible without this feature.

Second, South Australian gulfs are two of only a few gulfs in the world in which the salinity increases markedly towards the gulfs’ heads. They are referred to as inverse estuaries, and are created when evaporation exceeds rainfall inputs. Salinity is a direct measure of oceanic influences. Regions of greatest salinities, such as Upper Spencer Gulf, are most sheltered from the inflow of oceanic currents. Increased salinity levels are, for instance, the main reason for the existence of extensive mangrove forests in the northern reaches of both gulfs.

So, which regions of South Australian gulfs would you think deserve the highest level of protection?

BHP Billiton uses the tidal features of Upper Spencer Gulf as a central scientific argument in defending its site choice for the desal discharge, and it classifies the Point Lowly region as the best discharge location. Tides are oscillatory features, moving water up and down an estuary over distances of 1–20 km (depending on speed) in a regular fashion. The associated tidal currents operate to enhance mixing of pollutants (such as desal brine) from a point-source discharge.

Phases of the tide during which effects of the Moon and the Sun amplify tidal currents are called “spring tides”. Phases during which these effects partially compensate each other, diminishing tidal currents, are called “neap tides”. Spring and neap tides occur on a roughly fortnightly basis.

A distinctive feature of South Australian gulfs is that tidal flows substantially weaken during a neap tide and, once in a year or so, even completely vanish. Explorer Matthew Flinders named this feature a “dodge tide”.

Tidal currents during a spring tide in Upper Spencer Gulf are extremely swift (>1 m/s). Even during neap tides, tidal currents are still moderate (10–20 cm/s) in this region.

Nevertheless, tides are of secondary importance to the ecology in the region, simply because they are insufficient to mix the hypersaline water of the Upper Spencer Gulf with waters of the lower gulf. Indeed, BHP Billiton’s argument based on tides rather than ecology is scientifically flawed, given that a similar argument could be applied to install an “army” of desal plants along the Great Barrier Reef, where tidal flows are relatively strong.

Desalination discharges operate like underwater garden sprinkler systems, pumping desal brine and residual chemicals from near the seabed into the ambient water column. Given that the desal brine is up to twice as salty as ambient seawater, it is heavier and therefore tends to sink to the sea floor. Mixing with ambient water dilutes the brine.

One of the biggest short-term risks involved with such discharges is the formation of dense layers of brine, only a few metres thick, creeping along the sea floor and being subject to depletion in dissolved oxygen owing to consumption by benthic marine organisms. Such “dead zones” can form during calm conditions and a lack of mixing (e.g. during a dodge tide) and/or failure of technology (e.g. leaks). Can we take the risk for such dead zones to form in the Upper Spencer Gulf?

In general, South Australia’s environmental legislation allows for regulated marine pollution within a distance of 100 metres from a discharge point. This pollution zone is called the “mixing zone”. Operating licence conditions, negotiated between the Environmental Protection Authority and the operators, specify environmental performance criteria for the edges of this pollution zone. For desal brine discharges, one of these conditions usually relates to a dilution threshold, which refers to a minimum number of litres of ambient seawater mixed with one litre of raw desal brine concentrate.

Although these technical details are important, the key question for the Upper Spencer Gulf discussion is the question of whether we should risk introducing such a pollution zone in the vicinity of the cuttlefish breeding habitat at all.

Unfortunately, on behalf of all its citizens and future generations, the South Australian government has decided to accept this risk. This implies continuous pollution at a distance of only 1 km from the cuttlefish breeding habitat at Point Lowly. As bottom feeders, adult cuttlefish reside mostly near the seafloor. How can adult cuttlefish avoid the pollution zone?

Has seawater desalination technology ever failed in Australia? In early 2008, Australia’s first desalination plant in Kwinana (south of Perth, Western Australia) was shut down on two occasions due to reduced dissolved oxygen levels in Cockburn Sound. Whether this discharge has caused environmental damage is uncertain; Cockburn Sound had already lost 80% of its seagrass over the past four decades mainly due to industrial pollution.

The Point Lowly desal plant will be a world-first experiment in a fragile and globally significant marine ecosystem. Failure of this experiment is a risk for the mining operations and a liability for the global desal industry. More importantly, this risk could have been avoided if the precautionary principle had been applied.

What will happen if the Point Lowly desal plant damages the marine ecosystem and the cuttlefish at some point in the future? Will appropriate actions be taken by BHP Billiton, or will they argue that natural factors (such as global warming) or other industrial polluters are to blame?

Any interruption of water supply in the event of a licence breach will lead to additional environmental hazards, as water is critical to radioactive dust control at the mine. BHP Billiton will presumably try to negotiate soft licence conditions for the desal discharge, and keep their primary water supply flowing as a top priority.

AdelaideAqua, the operators of the Adelaide desal plant at Port Stanvac, negotiated a much softer operating licence based on less than half the dilution threshold of 50:1, which was assured in the Environmental Impact Statement and which is one of the desal plant’s governmental approval conditions. How can such behind-the-scenes negotiations be prevented?

Despite politicians’ and private companies’ assurances, the introduction of continuous marine pollution to one of Australia’s most precious marine ecosystems can hardly be classified as “world’s best practice”. We can only classify it as a gross failure of South Australia’s environmental legislation.

A list of references and supporting documents are available on request. Further information and videos are available online at http://CuttlefishCountry.com. At the time of writing (October 2011), the South Australian Parliament was in the process of amending legislation that will grant BHP Billiton the permission to pollute the Upper Spencer Gulf with toxic desalination brine in close vicinity to the world’s only mass aggregation of the giant Australian cuttlefish. The final decision in this matter was expected before the end of the year.