Rakaia flow Wildlife link 'vulnerable’

Press, 6 November 1984, Page 4

Rakaia flow Wildlife link 'vulnerable’

The Rakaia River catchment’s natural flows and lake levels must not be altered until it was shown that this would not significantly affect wildlife, the Planning Tribunal was told yesterday. Mr C. F. J. O’Donnell, a scientist employed by the Wildlife Service, said that the whole of the Rakaia River, including the riverbed below the gorge, was of outstanding value to wildlife. He was concerned that any reduction in the flow of the river could be detrimental to wildlife, particularly to the endangered wrybill. The bird had a population of less than 4000, but its breeding population on the mainstream of the Rakaia River was outstanding. He believed it would be very vulnerable to changes in its natural habitat. Mr O’Donnell said that it would be inappropriate to decide on water resource allocation now because of the river’s value to wildlife and the lack of information about the consequences to riverbeds. Any modification of lake level and flows would also be detrimental to waterbirds, he said. He was particularly concerned that tne endangered southern crested grebe would no longer be able to breed at Lake Heron if the lake level fluctuated more than 250 mm. The tribunal yesterday resumed its hearing of appeals against the Rakaia River draft conservation order after a one-week adjournment. The hearing is expected to last about another three weeks. Continuing the Crown’s evidence, Dr P. R. Todd, a fisheries scientist employed by the Ministry of Agriculture and Fisheries, gave

broad evidence about salmon farming in New Zealand and, in particular, salmon farming on the Rakaia River. Dr Todd has been involved with research at the Glenariffe Salmon Research Station in the upper Rakaia River, but also told the tribunal of developments at the two other salmon ventures on the Rakaia; the Blackford Stream Salmon Ranch and the New Zealand Salmon Company Ltd. He said that the number of hatchery reared fish returning from releases on the Rakaia River had increased from seven in 1978-79 to approximately $3OO in 1983/ 84. If the planned releases of 1.5 million hatchery fish went ahead during the next three years he expected the total annual run to double or treble. Replying to questions from counsel and the tribunal Dr Todd said he believed that salmon farming had considerable potential as an income earner for New Zealand. The Rakaia provided New Zealand’s most important concentration of salmon farming and produced, major part of salmon oVa used in this country. The rates of river flow provided for under the draft conservation order would be sufficient for the upstream passage of most returning adult salmon, but he was concerned about the return of large fish. Although these formed only a small percentage of the run it was important that upstream passage was maintained for fish of all sizes to maintain the genetic diversity of the stocks, he said. The tribunal comprises Judge Skelton (chairman), Mrs N. J. Johnston, and Messrs H. M. Dodd and R. A. McLennan.