The rare Nooksack dace is found only in four streams in Canada, all in the Fraser Valley, and its habitat is dwindling.
Mike Pearson, the world’s leading authority on the tiny, timid fish that arrived before glaciation and survived in a refuge, says it will soon only be found in two watersheds.
“The dace I think are highly likely to wink out in a couple of watersheds. They are on the edge,” he said during a tour of the small streams that shelter the dace and another endangered species, the Salish sucker.
Mr. Pearson, a private consulting biologist, has been studying – and fighting to protect – both species since he did his PhD thesis on them a decade ago.
But lately he’s begun to think he’s losing the battle, at least as far as the dace is concerned. The annual funding grant he’s received from Environment Canada for the past 10 years, to do research and habitat restoration, has not been awarded this year.
In March, he got a three line e-mail inviting him to apply again next year. No explanation offered. The lowly dace, it seems, is not high on Ottawa’s environmental agenda.
Mr. Pearson said he intends to put in for funding next year, but then shrugs dejectedly and wonders what will happen to the Nooksack dace in the meantime.
Things look a little brighter for the Salish sucker, he said, because it has a wider range, being found in 11 streams, and it can tolerate poorer water quality.
“The Salish sucker is a pretty tough little fish. It will tolerate a lot less oxygen than salmonids, for example. I’m hopeful for the sucker,” he said.
His research has shown the Salish sucker is found in more places than was originally thought, so the status of the species may soon be upgraded from endangered to threatened.
But the dace has the misfortune of needing clean, oxygen rich water to survive. And that is becoming a rarity in the bucolic Fraser Valley, where farming dominates the landscape.
“Farmers clear their land right up to the stream banks,” he said, pointing across one pasture where the only vegetation left along Elk Creek is a rim of high grass. “There is no shelter, and in the summer, the water heats up. The other problem is the massive over-fertilization of the fields. There is three times as much manure spread as can be taken up by the plants. The excess just goes into the groundwater and into the streams. So you are fertilizing the streams and heating them up and basically turning them into hydroponics,” he said.
A third factor is the disruption of stream flows caused by an extensive dike network along the Fraser. The river is hemmed in by dikes, and the streams that flow down from the hillsides have to go through flood-control gates, which are often closed. When the gates are shut, to hold back high water from the Fraser, the streams have to be pumped through into the big river. Any fish coming down the streams are ground up, and spit out into the Fraser.
Mr. Pearson said a number of “fish friendly” pumps have been installed in the past few years, but they are costly, and most streams still run through fish grinders.
Fully grown, a Nooksack dace is only about 10 centimetres in length. The Salish sucker is twice that size. But neither fish is big enough to have any sporting or commercial value.
So why worry about saving them?
“I understand why people would ask that,” Mr. Pearson said. “The thing is, if you save the dace and the suckers, you are saving a lot of other things, too. Wherever I find dace, I find steelhead. Wherever I find suckers, I find coho.”
Mr. Pearson said the small streams that lace the landscape of the Fraser Valley were once prodigious producers of salmon. Many of them still have runs of chum, Chinook and coho. He knows, because he often catches young salmon in the traps he sets for dace.
But because of degraded water quality, the productivity for salmon has fallen dramatically in the network of streams and sloughs in the Fraser Valley..
Save the dace, said Mr. Pearson, and the salmon population will rebound. Better pumps, stream bank protection, and controlled fertilization practices are what’s needed.
“The solution is simple technically. Politically, that’s a different story,” said Mr. Pearson.
Farmers are resistant to any changes that might threaten their control of land and they have cowed Fraser Valley politicians by complaining loudly. But they need to be reminded. The dace were here first. They have a right to survive. And saving them will save the salmon, too.