4862 NEW ZEALAND GAZETTE, No. 194 18 NOVEMBER 2005

to support plant growth would probably be greater and thus extend to the harbour bed. Although Dr Grange’s views on these two points were unsupported by data, they were based
on his considerable experience, and appeared to us to be logical, and therefore persuasive, in the present context.

Thus, using Dr Grange’s definition for littoral coastal waters, and in the absence of plant or light distribution data for the entire harbour, we think that even the deeper reaches of the
harbour at depths greater than 20 metres may properly be regarded as "littoral".

Any doubt about this may not be material, however, in light of Dr Zeldis’s further evidence about the estuarine characteristics of the harbour.

Dr Zeldis put forward a number of definitions of estuaries. A common feature is that estuaries are coastal regions in which salinity varies as a result of fresh water runoff from the land. There is an issue as to how much fresh water runoff, and what salinity variation, determines the estuarine characteristic of the waters. We found Dr Zeldis’s evidence about the estuarine nature of the upper reaches of Akaroa Harbour very compelling. He relied for
his opinion upon the presence there of estuarine species. The other estuarine characteristic upon which Dr Zeldis relied was the data relating from salinity variation in the upper harbour arising from input of streams from the local catchment.

Dr Zeldis also provided evidence of salinity variation throughout the rest of the harbour with a characteristic salinity gradient from the upper reaches to the harbour mouth. Everywhere in the harbour, the salinity is "typically lower than purely subtropical water offshore".

The levels of salinity in the inner harbour are certainly lower than in the outer harbour, suggesting that the inner harbour is more estuarine in nature than the outer harbour. However, Dr Zeldis’s expert opinion on whether the whole of Akaroa Harbour may be characterised as estuarine in nature was this:6

5. Conclusion

5.1 It is clear, from both biological and physical standpoints, that Akaroa Harbour is estuarine. It supports estuarine fauna in its inner half, and its salinity is variable throughout its length and typically lower than purely subtropical water offshore. The main reason for this salinity depression is stream flow from the surrounding catchment, although it is clearly periodically influenced by other Canterbury rivers draining the Southern Alps.

We accept his expert opinion.

Conclusion

On the basis of the evidence before us about the terms "littoral" and "estuarine" as they apply to Akaroa Harbour, we conclude that the whole of Akaroa Harbour comprises coastal waters that are both littoral and estuarine. While there is a lack of data as to light penetration in the outer harbour, raising a question as to whether that area is "littoral" in the terms that were presented to us, we accept Dr Grange’s hypothesis. Moreover, we accept Dr Zeldis’s view (which was unchallenged before us) that the whole of the harbour is estuarine in any event, so the statutory criteria are met even if a small area of the outer harbour may fail to meet the "littoral" tests.

6 Supplementary statement of evidence, John Raymond Zeldis, paragraph 5.1, page 4.