Clarence River rock extraction: Potential effects on wildlife and their habitat

Abstract

Tranz Rail Limited seeks consent to take rock from the Clarence River and minor tributaries for its proposed ferry terminal development at Clifford Bay. The purpose of this report is to: describe wildlife values of the lower Clarence River in the area of proposed rock extraction and associated works; identify impacts to wildlife from the extraction works and necessary maintenance activities; and recommend any mitigation measures necessary. My main field inspection occurred on 25 October 1997, during the wildlife breeding season. Neither the Miller or Wharekiri riverbeds are of 'value' to wildlife. Wildlife presence on the Clarence riverbed between the SH1 Bridge and Comer Hill was recorded. In the active riverbed only common species from the typical braided river bird community were recorded. From a wildlife management and conservation perspective there are few concerns. On the true left bank a stable 'island' contains a degraded kanuka shrubland which is home to a variety of forest bird species - this area may be significant ecologically. If rock extraction is proposed from the active riverbed only then the main concerns would be associated with protecting the character of this shrubland from proposed access and rock storage facilities. Neither issue should be insurmountable. If however, the 'island' is a necessary source of rock substrate or is required for very large scale storage then mitigation efforts will be needed elsewhere.