The loss of fisheries habitat, cockle habitat in particular, within Otago Harbour would be minor as a result of Port Otago's proposed Project Next Generation, consultant fisheries scientist Richard Boyd says.
The waters and coast of Otago Harbour supported a diverse range of fish and shellfish resources that were common throughout New Zealand waters, Mr Boyd said.
"There is no fisheries-related reason why Port Otago Ltd resource consent applications cannot be granted."
The harbour had what was believed to be the largest population of cockles in New Zealand, which was being experimentally harvested by Southern Clams.
Within the harbour, effects of the dredging, including suspended sediments and sedimentation on fish and shellfish resources, would be localised around channel margins and the swinging basin, and would be minor, he said.
"This will not impact on the availability of cockles for recreational or customary cockle gatherers."
Most of the effects at the disposal site AO would be confined to the period of dredging and disposal and had been minimised by careful design of the new channel alignment.
Effects on fishery resources from incremental dredging would be "very small" and would affect a very small area around the dredge and disposal sites, Mr Boyd said.
Some effects from the use of a larger contract dredger would be greater and extend over a larger area.
"Effects of the proposed dredging and disposal on fishery resources and fishing in coastal Otago will be minor."
He believed the draft consent conditions and proposed environmental management plan addressed all the relevant issues associated with potential effects on fisheries.
Consultant zoologist Martin Cawthorne said despite Hector's dolphin numbers being reduced by recreational and set-net fishing, the population had lived near Otago Harbour during the 142 years of maintenance dredging and other activities within a busy harbour.
Of the 11 marine mammals found in the Otago area, only New Zealand fur seals and sea lions, Hector's dolphins and southern right whales were likely to be influenced by Project Next Generation, Mr Cawthorne said.
"Fur seals will be unaffected by dredging and other activities. Sea lions are adaptable, generalist feeders and will be unaffected by activities within Otago Harbour."
The potential risk to right whales was considered to be very low, he said.
"It is most unlikely that there would be any detrimental effects to these animals from vessel activities and traffic."
• Environmental consultant Dr Paul Mitchell said there was no planning reason why the consents sought by Port Otago could not be granted.
"The granting of the consent ... in my opinion promotes the sustainable management of natural and physical resources, as contemplated by the RMA [Resource Management Act]."
Adverse effects were to be appropriately avoided, remedied or mitigated and could be managed through consent conditions, he said.
The proposed works would have significant and demonstrative positive effects in terms of sustaining the social and economic wellbeing of the community, Dr Mitchell said.
