Saving An Ancient Fish

Montana Fish, Wildlife and Parks Fisheries Biologist Tyler Haddix knows just how complicated Pallid Sturgeon recovery in the Upper-Missouri River Basin can be, he's been working on it for 15 years. In fact, according to Haddix, it's a problem nearly 70 years in the making and over the last 25 years, biologists have been trying to solve it amid environmental and economic concerns from all involved.

Basically, the problem is that Pallid Sturgeon have been unable to reproduce naturally in the Missouri and Yellowstone rivers since the construction of the Garrison Dam in northern North Dakota. The primary reason they are unable to reproduce in either river is not because they do not spawn-although that is mostly true in the Missouri-but, rather, because the hatchlings are unable to develop out of their drift period before settling in the anoxic zone of Lake Sacajawea and end up perishing.

Pallid Sturgeon are able to spawn in the Yellowstone River about seven miles from its confluence with the Missouri, but the drift rate of the river makes recruitment (the development from embryo to sexually mature adult) impossible. Haddix said FWP is trying to solve the Yellowstone River problem with a possible fish ladder that would allow the Sturgeon to travel around Intake and up stream to spawn well above the lake. It is unknown whether that fish ladder would solve the fish's problem in the Yellowstone, but-not content on waiting to find out-FWP has a separate theory they think could help restore the fish to a natural state in the Missouri below the Fort Peck Dam.

As the Courier reported in early August, the Army Corps of Engineers is conducting an Environmental Impact Statement to propose a change of flows in the Missouri River below the Fort Peck Dam. The proposal would increase flows to around 33,000 cubic feet per second in Spring and keep it there until the Pallid Sturgeon can travel up the river and spawn. Then the Corps will cut the flow to bring the river level to around 8,000 cfs to allow the embryo time to become mobile before hitting the lake.

That proposal has been met with resistance from irrigators along the Missouri River from Fort Peck to Lake Sacajawea (for more see "Corps Plans Extreme Flows From Fort Peck" in the Aug. 5 issue of the Glasgow Courier).

"I just want to clarify that it is the Army Corps of Engineers that will be deciding what kind of flows come out of their dam," said Haddix. "And it's the Fish and Wildlife Service that's kind of holding the Corps of Engineers feet to the fire through ESA (Endangered Species Act), because it's a federal project that is shown to have a detrimental effect on an endangered fish."

The role of FWP in the process is to protect and manage all the fish in the river said Haddix, but that through funding from the Corps, FWP has been researching Pallid Sturgeon recovery and proposing the hypothesis on the fish's recovery. "So, it's not FWP proposing these flows," clarified Haddix, "what we've been doing is being an advisor to the Fish and Wildlife Service and the Corps telling them what we think is right for the fish and what needs to be done."

The effects of the flows on farmers are not lost on FWP. Haddix clarified that much of the proposal was altered to address concerns for irrigators and land users especially concerning the low flow rates proposed in July. "Being with the State of Montana, we're very concerned about our irrigators and our local landowners, so-although Sturgeon are very important to us-we're trying to balance the fact that we could potentially get Sturgeon recruitment and have flows that are conducive to the irrigators."

Haddix pointed out that a flow of 33,000 cfs would be gauged at Wolf Point and would not just come from Fort Peck Reservoir. Some of that flow would occur naturally from the Milk River and other tributaries like Porcupine Creek. He also pointed out that in 2011-a year cited by irrigators for it's extreme effects on the river-the flow at Wolf Point was in the 90,000 cfs range.

The Pallid Sturgeon has been listed endangered since 1990 and no natural recruitment has occurred in the system since the 1950s. FWP knows this because of Carbon-14 signatures in the remaining naturally-occurring adult fish. Through Carbon-14 signatures in the bodies of those sturgeon it was established that they were born during the nuclear-testing era of the 1950s, and since that time ended, the radioactive material has since been reduced in the atmosphere.

"So, basically we can go back and we can see that those fish were born when atomic bomb testing was still going on," said Haddix. "So we know that they are very old."

In fact, the only saving grace for the Pallid Sturgeon is how long it lives, according to Haddix. Since it took from the 1950s to 1990 to realize that the fish was endanger of going extinct, had the fish not been so long-lived it is possible they would have gone extinct in the Upper-Missouri River Basin before a plan for recovery was possible.

Currently there are only about 100 wild Pallid Sturgeon remaining in the Yellowstone and Upper-Missouri River system. For biologists like Haddix, the best way to begin recovery is to find out why the fish is not successfully recruiting into the population. They established that the distance of drift from hatching to being able to swim freely was an exceptionally long distance and, because of the lake, they needed a long stretch of river to successfully mature.

Haddix pointed out that currently the fish do spawn in the Yellowstone but only about eight miles above the confluence of the two rivers and as a result they are too close to the lake to survive. In the Missouri, most years the fish never travel up the river to spawn. FWP theorizes that the fish would come up to spawn if triggered by a high water flow such as those that occurred in 2011 and 2018. In fact, it was the capture of free-floating embryos in the Missouri in 2011 and the migration of Pallid Sturgeon up the Missouri in 2018 that solidified their hypothesis and made them move forward with proposing flow rates from 25,000 to 30,000 cfs.

Despite the proof that fish spawned up river in 2011, Haddix said no evidence that the hatch survived into adolescents has been found. Instead the high flows likely swept the hatchlings down stream about 200 miles into the lake before they developed. That meant FWP had a second issue to solve-how to give the hatchlings enough time to develop into fish before reaching the lake.

Originally the Corps' plan called for a reduced flow of around 4,000 cfs, but after further study and feedback from landowners, FWP pushed to revise that rate to around 8,000 cfs at Wolf Point. It's believed that such a rate of flow around the time the eggs hatch will give the fish ample time to become free swimming and offer them a chance to reach sexual maturity and repeat the cycle. It will be decades before they know if it works though, since it takes that long for the Sturgeon to become mature enough to spawn.

"So we had that huge water year (2011), and then people kind of tied what we've been saying to that huge water year," said Haddix. "Well the good news is in early 2018-the Missouri River at Wolf Point-we had early flows, and they were actually spilling out of the dam, not a lot of water not like 2011, but combined flows of the Milk and the Fort Peck Project at Wolf Point were about 25,000 cfs in 2018 and we saw migration of adult Pallid Sturgeon come all the way up to the spillway area."

Haddix said that despite the migration up river, the flows were not maintained long enough to give the fish an opportunity to spawn in 2018 and they traveled back down river to spawn in the Yellowstone. He also pointed out that FWP did not receive or hear of complaints from land owners of adverse effects from river flows, which meant they had a good target to aim for when assessing flows that were suitable to Pallid Sturgeon and landowners.

"Other evidence that this might work, is that we know the fish will migrate up here at about 25 to 30,000 cfs, we need to keep them here and then they need to spawn, and then what we've done is, the USGS, FWP and Fish, Wildlife Service have done this drift test and we've taken day old embryos... placed those fish in the river... and we monitor how they drift with the river current to understand how much distance they need to grow," said Haddix. "When we put those days-old fish in the river at Wolf Point we've seen evidence that they've survived."

Evidence is strong, stressed Haddix, that given an opportunity to migrate upstream to the Fort Peck/mouth of the Milk River Area, given time to spawn and then given time to drift and develop, the Pallid Sturgeon could become a viable natural species under the ESA and begin the long road to recovery and delisting.

Still, Haddix said, the effects for farmers and ranchers has been a constant concern for FWP from the beginning. They have even gone as far as to submit comments on behalf of landowners for the Environmental Impact Statement the Corps is required to do under the National Environmental Protection Act.

"So we're really cognizant of what the landowners and irrigators need," said Haddix. On concerns about low flow rates coming from Fort Peck, he said the agency submitted comments against lower flow rates aiming to get them up high enough for pump sites while still being viable for the sturgeon. FWP was also working to shoot the elevations for the low-flow line at 8,000 cfs at over 40 pump sites to make sure the rate would allow the operation of irrigation sites. "We definitely do not want to drop the flows too low, and the idea is to slow the river down and give those fish more time to develop but with these current tests the more important part is getting the fish up to see if they spawn," explained Haddix. He added, "the low-flow period is not quite as high of a priority for us."

Haddix pointed out that if the tests were successful for this iteration of testing, further tests would be done to better balance the effects on irrigators and the benefits for the Sturgeon in the coming years.

"We do not want to flood people out or make their lives hard for this test, that's not the objective," emphasized Haddix. "We believe, Fish, Wildlife and Parks believes, we can get the fish to have a response, a positive response, and make it very palatable for landowners."