Meeting for Pallids
BY BRUCE HALLMAN, NEOSHO NFH
Twice a year, a veritable Who’s Who of pallid sturgeon experts assembles in Blue Springs, Missouri to talk shop. The latest meeting was the last week of January, and the Neosho National Fish Hatchery (NFH) was represented by hatchery manager Roderick May and lead biologist Jaime Pacheco. I was invited to tag along as well.
Meeting as they always do at the Burr Oak Woods Conservation Nature Center (a very nice place to visit, by the way), about 35 came from all directions – some many hours distant. At least five states were represented in this assemblage, with others invited but absent. No less than a dozen organizations (federal, state and others) and three fish hatcheries were a part of this vital interaction.
We depend a great deal on the discussions and decisions made by this team to guide and direct our operations here in the southwest corner of the state. The home of the pallid sturgeon is mainly the Missouri River – the longest body of water in the United States and the fourth longest in the whole world (when measured down to the ocean). This massive river winds more than 2300 miles from the high mountains of Montana until it empties into the Mississippi at St Louis.
This ancient creature (some have nicknamed it the “dinosaur fish”) has withstood many millions of years of variable conditions and yet survived. So many other species have gone extinct over those same millennia. Population numbers indicate that whatever is going on now is likely its toughest challenge yet. While never super abundant along its range, there are perhaps less than 1000 mature pallid sturgeon adults in the lower 800 miles. Despite having many thousands of hatchery-raised young for the past 15+ years from Neosho NFH alone, there is a struggle for “recruitment” or establishment in the population from many new fish at all.
Credit: Bruce Hallman, USFWS
So these meetings of minds look to address current problems (lack of suitable habitat for feeding or spawning, changes in water flow, pollution, channel dredging, illegal harvest, etc.) and present findings towards solutions. We heard from several different crews that work the river and search for adult sturgeon. From Nebraska and Missouri reports, the same grim results resounded – they just aren’t seeing many fish out there. One Missouri Department of Conservation team works the 200 mile stretch of the Mississippi between the Missouri and Ohio Rivers. Detailing their three year effort to locate adult sturgeon, using over 130,000 baited hooks left overnight in the water, they were only able to catch 34 pallids in total. In three years! While not quite as foreboding, the other crews from upstream echoed these dismal findings.
Another important avenue of sturgeon study concerns genetics. Using samples taken from many fish over many years and many miles of river, a disturbing trend has surfaced. Genetic analysis has found that the more downstream a fish is, the more likely it is to be a hybrid. This means that it has mixed heritage – somewhere in its history there is another species (in this case, shovelnose sturgeon) that has crossbred with a pallid to produce it. For recovery purposes, the production hatcheries such as Neosho NFH will never want hybrid fish to spawn and raise. To keep a species going, purebred adults are needed for breeding and transmitting their genes to future generations. Alarmingly, pallids caught below St Louis were found to be almost 99% hybrids. Fortunately, higher upstream the genetics show more hope.
More developments that may affect us at Neosho NFH concern population demographics in the river; in particular, a fish called a chub. Various species live in the Missouri River and due to their smaller size; they are a food source for sturgeon and other larger fish. There have been some experimental moves toward breeding them for captive food sources as well as for release into the river. Other smaller fish might work as well for these purposes.
Another concern that was raised involved the alarming population shift away from sturgeon as top predator and toward large catfish and Asian carp. These fish will be competing for food with the pallids. Evidence that this is the case comes from the scrawny condition of most adults when captured. Neosho has proven to be a good holding station for these emaciated individuals as all our fish gain significant weight during their stay. We are currently feeding them live trout and they do quite well under our watchful care.
Finally, the complex situation in such a gigantic river isn’t figured out easily, quickly or cheaply. Already many millions of dollars have been funneled into this effort to save this beautiful fish, and more will definitely be needed. Talk of flow rate, sediment release, sandbar formation, interception zones, bedform examination, reproductive readiness, laser ray analysis and other topics all are aimed at this one goal. Let’s hope that Neosho NFH can continue to be involved for the duration and that a strong species rebound can come soon for our beloved dinosaur fish!
We are progressing in our sturgeon program here, working to make things even more productive for our goals. On tap are UV treatment, filters and chillers to get our facility equipped for better water handling. As for our other programs, all is well with our rainbow trout program. We are still producing 230,000 10-inch fish for mitigation efforts at Lake Taneycomo in Branson, Missouri. We are moving toward our third year working to breed endangered Topeka shiner minnows. Still in progress is our desire to move into endangered freshwater mussels, particularly the Neosho mucket. And we always want to see what else we can do to conserve, protect and enhance for our country!