Abstract:
The Tahi Estate was chosen for an investigation into Biodiversity Offsetting as it presents a more complex and unusual form of development than is commonly encountered. The property is being developed as an ecotourism destination; having been a cattle farm for much of the 20th century. As a consequence many of the developments are about enhancement of the biodiversity values for visitor experience. It is these biodiversity enhancement developments, together with the more usual infrastructure and building developments that are considered here. The analysis of the developments was carried out using standard biodiversity currency analyses. The results of the various analyses suggest that most of the developments on the Tahi Estate can be considered to be positively offset, i.e. no net loss of values. However, in one case – the effects on the Sand daphne population appear to be negative. In this latter case it is also unclear as to how the negative effects could be offset. The offset programme was tested against the 10 principles of biodiversity offsetting and can be considered to conform. In particular the test of additionality can be considered to have been satisfied. The Tahi project also questions the use of a strict like-for-like substitution as the only valid approach to offsetting. The owners have flooded some severely degraded wetlands to create lakes, in essence created alternative high value ecosystems. A case is made that depending upon the currency model used, it may still be possible to include this type of ecosystem substitution in the current offsetting approach. Numerous methodological and logistical problems were encountered in applying the required approach. Recommendations are provided as to how to overcome the difficulties encountered. In summary, if some of the methodological and conceptual problems could be resolved, this approach would provide a useful tool in the assessment of effects of developments. It could also be used by landowners to devise approaches that would result in no net loss and perhaps some gains in biodiversity values consequent upon development.
