Report gives 'interesting perspective' on Southland's 'lost rivers'
Gore prides itself on being the brown trout capital of the world, yet if you read the report into Southland fisheries from the NZ Association of Freshwater Anglers, that claim could be in jeopardy.
Thousands of overseas anglers visit the south in the hope of hooking themselves a trophy trout on our uncluttered riverbanks, which is why two Australians have just opened a fly fishing shop in Lumsden – smack bang in what they call a "world class" trout fishery.
Venture Southland don't keep statistics on the number of anglers visiting Southland and how much they spend, but anecdotal yarns from towns like Lumsden, Athol and Balfour would suggest that anglers are buying up property so they have a summer bolt-hole within driving distance of some of the best fishing they're likely to find.
But now, more than 15 southern waterways appear on a list of rivers "lost or in noticeable decline" as public trout fisheries.
The list was coordinated by NZ Federation of Freshwater Anglers executive member Steve Gerard.
Southern waterways appearing on the list include the Pomahaka, Oreti, Makarewa, Mokoreta, Upukerora, Whitestone and Mararoa rivers, and the Waipahi, Otamita, Waimea, Lora, Otapiri, Dunsdale, Hedgehope, Titipua, Waimatuku, Orauea and Mimihau streams.
Gerard said New Zealand's trout fisheries were "going downhill".
The mapping listed rivers where a significant loss of opportunity to catch fish had been identified, and highlighted "the significant decline in our freshwater fisheries".
Gerard said the causes "generally relate to developments such as large scale irrigation, intensive farming - particularly dairying - and forestry clear-felling and forestry monocultures within catchments".
"It's very eye-opening and a sharp reminder with an election looming, that water and rivers is an issue to take up with politicians."
The Pomahaka River, between Gore and Clinton, was formerly one of the country's prime trout rivers, "but water quality has declined markedly since about 1980, primarily because of intensive agricultural development," the federation says.
The Waimea Stream, near Mandeville, had "some of the highest nitrate levels in Southland", and had become "no more than a dirty ditch in parts".
Angler use of the Oreti River, between Winton and Invercargill, showed "a drop of a whopping 11,900 angler days per year since 1995".
Agriculture was not only culprit identified by the federation. Removal of willow trees shading was blamed for decline in fisheries values in the Upukerora and Whitestone rivers near Te Anau.
Federation president Graham Carter said the list was compiled using NIWA angler usage and perception surveys and expert angler input.
"Only rivers where there was an obvious decline have been listed. There remain a significant number of others where there wasn't enough collaborating information to include them."
He said the purpose of the list was to raise awareness "of just how big an issue this really is".
However, Environment Southland director of science and information Graham Sevicke-Jones said the report is "quite a leap of faith" and gives an "interesting perspective" on the province's waterways.
"It gives a useful perspective of one group's perception but I'm not entirely sure about the accuracy of the information. Some of their information does not quite match up with ours.
"The change in the angler's perception of the fishery is rather simplistic when the problem is more complex than that. The report doesn't have any new information in it."
"They have taken a step into saying the fish stocks are depleted because of A, B or C when it is more complex than that. They have not said over which time periods their perceptions are from and there has been a lot of change in many factors, such as land use, for example.
"The cause and effect can be any number of things and I would think that you can't just blame water quality. That's not to say there has not been a change in water quality, but some of the streams they have highlighted have improved, some have stayed consistent and some have degraded.
"I would be loathe to go straight into a water quality discussion - it's bigger than that. When you deal with any change there are flow on effects that need to be addressed as well."
He said less angler effort on some waterways could be due to access issues, as an example.
He said some fisheries used to be stocked regularly and because they were not now there would obviously be a perception that the fishery had deteriorated because it had to be self-sustaining.
"That may have had an impact, but we have not done an analysis on that so we do not know."
ES's Water and Land plan, which it was currently consulting on, would address some of the issues, he said.
He was also sceptical of the timing of the report's release, just before a general election, and was critical of the use of a skull and crossbones being used for waterways the NZFFA had used to highlight waterways with depleted fish stocks.
"They've taken an emotive approach, but they have raised awareness of the problem which can be a good thing."
But it's not time to hang up the waders just yet.
Southland Fish and Game manager Zane Moss says there is still some good fishing to be had in the rivers highlighted in the report.
"The skull and crossbones they're using probably isn't quite appropriate because some of those rivers are still very popular and there's still some good fishing to be had in some of them.
"The report is pretty general but it has not come as any great surprise. Some rivers have declined more than others and angler usage and effort has declined in some rivers more than others.
A decline in trout numbers in a river was mostly due to sediment in the habitat, which was usually caused by intensive farming practices.
"Sediment is the biggest issue and it's inevitable, with more hill country being developed for farming, that it will run off and end up in the rivers.
"The bigger rivers that have more water through them from the headwaters are less impacted by intensive agriculture as opposed to the smaller streams so it is inevitable that there will be less fishing in them."
He sited the Otapiri Stream, where there had been a 90 per cent drop in trout numbers in one section of the river since the 1960's.
"We're not saying all the rivers have declined to the same degree."
Lets hope it stays that way, and that other waterways eventually improve so that Gore's trout statue doesn't become a reminder of something that once was.