▶️ The Great Outdoors: High Desert drought helping effort to remove carp

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There are some silver linings to drought conditions plaguing the High Desert.

Officials have been trying for decades to control and remove carp from Malheur Lake. This year, Mother Nature is serving them up on a platter. 

The water is so shallow, carp are leaving the lake and concentrating in the Blitzen River where wildlife managers are scooping them out by the ton.

“We’ve been using a couple of different methods,” said Dominic Bachman, aquatic biologist for the Malheur National Wildlife Refuge. “What we are doing now is using hand wands in the river. What that does is stun the carp. As the carp are stunned, we net them up and then we move them to a loader and then to a dump truck from there.”

These are big fish that weigh an average of 15 pounds apiece.

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Good reflexes are required to net them, strength to carry to them and coordination to toss them into bins. The scene is reminiscent of Pike Place fish market in Seattle where vendors toss salmon around putting on a show for shoppers. 

But here on the refuge, the carp are being thrown with a bit of vengeance because they inflict serious damage on the ecosystem. 

“Malheur Lake could, at one time, produce up to 150,000 birds during a good water year,” said Jeff Mackey, Malheur Wildlife Refuge Manager. “Since then, it’s been an ecological transformation from the emergent marsh to what we have now which is a turbid environment.” 

The carp impact Malheur Lake through their feeding patterns by continually stirring up sediments. The sediments block the sunlight which the plants need to grow. Without sunlight, that important component of the marsh is lost.

Another silver lining of drought is the emergence of native vegetation from the exposed lakebed, out of reach of the carp. 

The race is on to remove as many carp as possible before the lake level rises in the spring, flooding the new vegetation and allowing carp to get back into those areas.

“When Malheur Lake is big, we could have millions of fish,” Bachman said. “Right now, we have much less fish. There’s no water in the lake for fish. All the fish are in the river and their population is extremely low, so every fish we get out we are really knocking the population down.” 

 

The goal is to remove 75% to 80% of the carp in the system. 

Wildlife managers are focused on the large spawners. Just one of them can ruin all the efforts to remove them.

A common female carp in good condition can lay three million eggs. 

“We cut open a giant one that had about five million eggs in it,” Bachman said. “They haven’t been able to spawn well the past two years because of the drought condition. Carp need to spawn on vegetation and the lake has been so low there’s very little vegetation out there they haven’t had any opportunity to spawn out there. There’s only a small portion of the river where they can spawn. This year I’ve only seen three fish that were born this year in all the efforts that we are doing.” 

Staff from federal, state and local agencies and dozens of volunteers came from miles around to help remove carp from the Malheur Wildlife Refuge.

“I’ve always been interested in natural resources. When they asked if we could do that for our lab, I was excited. It’s better than being in a classroom,” said Trent Stevens, a Treasure Valley Community College biology student

 

So, what becomes of all the carp? Refuge managers have tried for years to develop markets for them. 

Commercial fishermen tried catching them with hook and line and turning them into liquid fertilizer, but the carp’s large scales clogged the spray nozzles.

A gathering of international chefs was held in Portland a few years ago to make gourmet dishes with carp to increase their appeal in restaurants, but in a land of salmon, trout, halibut and sturgeon, there’s just no demand for carp as table fare.

“On a small scale, we have people who use carp to fertilize their garden. If you want to come out and take them home, they make great fertilizer,” Mackey said. 

How does the public get a hold of that source?

“They just call the office. We only do this certain times of the year and we don’t do it every year. But if they call us, we can tell them when we are doing this work and encourage them to come out. Bring a bag. Bring a bucket. Bring a pickup truck, a dump truck, whatever you want. We’ll give it to you.”

A local farmer takes a lot of the carp, drops them in a hole in the ground and mixes manure and straw. When it’s broken down into compost, the concoction is applied to alfalfa crops which reportedly grow up to seven feet tall.

“The size of the lake is very dependent on how it is the year before and it’s not very big right now. We aren’t anticipating a very big lake next year so it’s possible a lot of this new vegetation could survive. That’s why we are putting full effort into carp removal, to give the vegetation the biggest possible chance,” Bachman said.

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