Has anyone noticed that "100 per cent pure New Zealand" has quietly been changed to "100 per cent pure you"?

Having been hung out to dry over their impacts on the environment, the exploiters, including Federated Farmers, have successfully lobbied to lower environmental expectations.

The irony is that overseas consumers' perception of New Zealand as clean and green will soon be our only marketing edge. The rest of the world will catch up and easily beat us on commodity prices, because their land and labour costs are so much cheaper.

We are delusional about how clean and green we are. Last year New Zealand honoured the United Nations Year of Biodiversity with the revelation that we are among the world's worst biodiversity losers.

We have 2788 species listed as threatened with extinction. Worse still is the reality that if more funding were available for further investigation, the species now classified as "data limited" would likely be listed as threatened and double the number on that list.

The historical reasons for this biodiversity tragedy are unmistakable. We drained 90 per cent of our wetlands, removed over 70 per cent of our native forests and dammed, straightened, stop-banked and engineered most rivers.

Indeed, we altered everything to suit us with total abandon, and this loss of natural capital continues unabated.

Apart from alpine areas, we have totally transformed the landscape. In the lowland areas the transformation has been so comprehensive that in Canterbury or Manawatu you can drive for an hour in any direction and not see a single naturally occurring native plant or animal.

This immense change didn't stop with the realisation that the damage done was irreversible. In fact, it has picked up speed - especially in the past 20 years. Nearly half of our lakes and around 90 per cent of our lowland rivers are classed as polluted.

Nearly all national and regional river monitoring sites show ongoing declines over most of the parameters measured. Our only freshwater mussel, freshwater crayfish, more than half of our 50 native freshwater fish species and all native aquatic plants are now listed as threatened.

It is crucial that these native freshwater species are seen not just as a loss of a biodiversity component of freshwater, but also as the canary in New Zealand's environmental coalmine.

We have gone too far. Surely it is time to admit, even if just to ourselves, that far from being 100 per cent pure, natural, clean, or even green, the real truth is we are an environmental/biodiversity catastrophe.

Why is it that New Zealanders are not outraged that we have slipped so far environmentally in such a short time? Surely this apathy reflects the power of the business lobby to keep the ecological truth hidden and to convince us that the economy is of prime importance. It appears this odd belief, that the economy is more important than the environment, has pervaded most government economic and social policy.

The reality is that until we all face up to the ecological truth there is no chance we can generate the political will to make the tough decisions required. Only then can we start to turn around these declines and possibly earn our clean, green image once again.

The controversial management of freshwater ecosystems in New Zealand is a good case study to see where it all went wrong.

There is a fundamental flaw in our freshwater protection. The most pervasive impacts are not controlled in any way.

The main impacts are diffuse nutrient pollution from intensive farming and sedimentation - mostly from inappropriate hill country farming. The dire condition of our lowland streams is directly related to the intensity of farming within their catchments and the vegetation clearance in steep country.

Neither of which are regulated at all. As long as there is a complete failure to control the major impacts of farming intensity and inappropriate land use then there is no way there will be a change for the better, let alone a halt in the decline.

Of all the impacts on freshwater only the "out-of-pipe" discharges are controlled in any way. While they do go through a consent process via the Resource Management Act (RMA) there are major weaknesses, failings and discouraging outcomes from this process.

There is a stark difference between the lofty ideals and promise of the act and the sad reality of the outcomes of its application. There is a relentless stampede of applications to take more from and/or discharge into the natural world, but that world is already overtaxed by supplying our basic "ecosystem services" - clean air and water.

Consent applications are handled by under-resourced council staff acting under the pressure of central government to speed up the process. Regional councils now openly admit to not enforcing consent conditions, in order to protect the local economy.

On the rare occasions where legal action is taken by councils and polluters are fined, the fines are generally pathetically small. It is often cheaper for the developer to risk a fine than to do the "right thing" environmentally. And, in most cases, the risk of getting caught is minimal. Prosecution takes time and money that struggling councils simply cannot spare.

The ideals of the RMA are, in fact, compromised by regional councils at nearly every step - from choosing not to publicly notify consent applications to stacking hearings panels with commissioners known to be sympathetic to a desired result. Regional councils are not independent arbitrators of the environment - they have a vested interest in "economic development" and, because of the election cycle, it's the short- term gain that's important to them and not the long-term loss to the environment.

In five decades New Zealand has gone from a world-famous clean, green paradise to an ecologically compromised island nation near the bottom of the heap of so-called developed countries. The core of the problem is a total lack of leadership from central government. Examples are the overdue (by 20 years) National Policy Statement on Freshwater Management, and the emaciation of the Department of Conservation, while funding to developers such as the Ministry of Economic Development is increased.

We need to face the fact that the economy is but a tiny subset of the environment - not vice versa. This country could easily be a high-producing clean, green example of sustainability for the rest of the world. But it will take courageous and knowledgeable leadership on ecological sustainability.

Dr Mike Joy is senior lecturer, Environmental Science/Ecology Group, Massey University, Palmerston North