Researchers in Oregon's Willamette Valley found young native fish thriving in ditches that fill with water during the winter months. The unrecognized habitat meant farmers had been inadvertently raising fish in their fields, in addition to their intended crops, for years. This report first appeared on Oregon Public Broadcasting.
GEORGE PEW: My name is George Pew.
And I grew up on the ground around here. My family has been farming at Shedd since 1851.
MAN: After spending 160 years farming the Willamette Valley, George Pew's family thought they'd seen it all.
GEORGE PEW: Fifteen years ago, I would have said we were grass seed growers. And now we're trying to diversify.
MAN: It's the middle of an especially wet Oregon winter, not the best time to visualize the grass, white clover and radishes that George has in mind. But it turns out it's the perfect time to find a crop, if you want to call it that, that farmers had no idea they were raising.
GEORGE PEW: It almost feels like we're running a zoo out here.
MAN: Researchers made a surprising discovery. They found fish living in the middle of farmers' fields.
MAN: We didn't even have the fish in our mind because, you know, who would have thought maybe we were fish farmers and didn't know it.
MAN: Don Worth learned he shares his grass seed fields near Tangent with several varieties of young fish.
DON WORTH: I have never seen them. But then when I'm out here, that isn't what I'm looking for. That isn't our business.
MAN: The team of scientists from OSU had their suspicions because common ditches cross the fields. They're bone dry in the summer, but fill up with water in the winter. And they drain out to nearby streams.
WOMAN: This grass seed farm used to be part of a network of seasonal streams that all came together and -- and flow into the Williamette River.
MAN: After all, a century-and-a-half ago, the Williamette River didn't follow one carved channel. Meandering braids spread out over miles, which created a watery network through dozens of side channels, which crisscrossed the Williamette Valley. White settlers changed all that. Farmers drained the land, filled in flood plains, pushed back the river and put some of the most fertile land in the country under the plow.
But a funny thing happened on the way to farming the valley -- no one told the fish.
WOMAN: I was really excited, because I thought, you know, let's see if there's any fish out in those ditches. And lo and behold, there were. So it was pretty exciting.
MAN: A team of researchers from Oregon State convinced 40 farmers across 187 square miles to become their partners in science.
Kathyrn Boyer and Guillermo Giannico led the project. Teams fanned out.
MAN: Take a sample right -- right here.
MAN: They suspected that these fields might well be thriving wildlife habitats, especially since the ditches are connected to nearby streams.
GUILLERMO GIANNICO: But what I didn't anticipate were the number of species we found. We -- we just were finding one or two individuals that just indicated that some fish managed to survive there, but we were getting dozens and, in some cases, hundreds of individuals in each trap.
MAN: Hidden in that murky, rain-churned water, they found 13 kinds of fish, including stickleback, red shiners, Chinook, pike minnow and more. Many were juveniles. That means the fields, during the wet months, are, in essence, a fish hatchery.
WOMAN: We didn't actually see them spawning, but we did see juveniles. So juveniles couldn't swim up here in the -- in the wintertime from the main stem. So they had to be raising young here.
MAN: 98 percent of the fish collected in the fields were native to Oregon.
MAN: There's a leech.
Oh, do you see one?
MAN: Yes.
MAN: In addition to all the fish, they found lots of fish food -- bugs, invertebrates, tiny critters galore.
MAN: Oh, man, there's a lot of ostracods.
MAN: Oh, beautiful.
MAN: Every one's really small this year.
MAN: Yes.
MAN: These habitats haven't been sampled before.
MAN: That's looking good, man.
MAN: And it doesn't look like perfect habitat for fish or bugs, so we weren't sure that we would find very much at all. But we have found a variety of things that live here. And that's really great.
MAN: Everything they find, the snails, leeches and tiny crustaceans, all must be able to survive the dry summer months.
GEORGE PEW: So they need special adaptations to survive that dry period and then to be around the next year, when the water comes back.
WOMAN: It may not be the habitat that we had back before anybody was here, but it certainly beats a subdivision.
MAN: Many biologists write off agricultural land as hopelessly lost for wildlife. But this study proves fish can thrive. That means how farmers operate has broad implications.
MAN: We use a fair number of herbicides and pesticides. And there is some concern that they might show up in the water.
MAN: The study found pretty good water quality. Researchers especially praised farms like George Pew's, which stopped tilling the soil. Straw lies there, breaks down on its own and keeps the soil from washing down those ditches. It filters the water, too, that runs off those no till fields.
MAN: I think most of us realize knowledge is a good thing and it's better to know your problems so you can correct them rather than -- than blundering along and causing problems that come back to bite you later.
WOMAN: It is kind of a wakeup call for them. And I think they're enthusiastic that, you know, that they've been working these lands for a long time and there're still fish out here.
GUILLERMO GIANNICO: I would say that in general, the picture is quite positive from -- from a farming perspective.
MAN: You know, we entered with the confidence that it wasn't going to be as bad as some people thought. But it was better. I think we were surprised it was much better than we thought it would be.
MAN: As winter ends, the ditch fish follow the draining water and go back to the streams and rivers that feed the Willamette. Many farmers never imagined they may well be growing crops and providing a critical refuge for native Oregon fish.
MAN: That's -- that's kind of a neat thing. Yes, we didn't use to run a fish hatchery, but now that the researchers have found the fish, I guess we're in business.
MAN: Wow!
MAN: Oh, yes.
MAN: Yes, I'm pretty sure that is.