Is offsetting sustainable?

How, under the RMA, to offset biodiversity values lost during source development projects?

A perspective from Dr Vaughan Keesing

Offsetting' has long been applied as a form of mitigation against loss - typically by protecting and restoring or recreating similar values at other locations. The concept of ‘no net loss’ has recently been gaining traction in biodiversity offsetting programmes, together with an expectation that the affected biodiversity values will be matched with the values in the offset area - a ‘like for like’ approach.

In practice, I, and many other ecologists, have found this approach to be often impractical, or impossible, and very costly. First, it necessitates quantifying the biodiversity present and approximating the ecosystem functioning on the affected features in far more detail than previously required. Second, the sometimes wide-ranging search for potential offset areas has similarly escalated in scale and cost because equally detailed surveys must be carried out to determine whether (or not) the offset values are a ‘like for like’ match or have the potential to be. This is further complicated by another offsetting objective - to find offset sites that are not yet currently protected and would benefit from restoration (i.e. they are not already in good condition). For big projects it is difficult to find suitable equivalent areas that are in a suitable state. Protecting existing good value has a debatably low return in the offset modelling. Creating new habitat is another option, but it is complex, time-consuming and cannot be guaranteed as a substitute for mature habitat loss. In my view, biodiversity offsetting must be flexible, practical, sensible and affordable, certainly not an academic exercise. The Department of Conservation is this year reviewing its Guidance on Best Practice Biodiversity Offsetting. I urge practitioners and stakeholders to take this opportunity to debate how the programme might be adapted to ensure its success and its cooperative uptake by practitioners.

For further information please contact Dr Vaughan Keesing

3 April 2013