BY NATHAN ECKERT, GENOA NFH
The production year ended with some of our mussel cages returning modest results, others returning negative results and one location yielding exceptional results. The upshot is that we have a significantly higher number of mussels on hand this winter than last. Last winter we held just over 6,000 mussels over winter in the mussel building. Increased production this year and some carry-over from last year has us looking at just shy of twenty-three thousand at 22,992. These mussels will be held in our black pan system using pond water that will match the normal temperature regime they would experience in the wild. Last year our over-winter survival of juveniles was 95%. If we are fortunate enough to experience that level of survival this year we should be set for exceptional release numbers in the coming years. Next year these animals will be placed in various locations for further grow-out and ultimately release. Some will go in our MARS trailer fed with Mississippi River water. Others will be placed in our standard mussel cages at good culture locations, and a portion will be grown on the grounds of Genoa National Fish Hatchery (NFH) to determine the best pond and culture technique for advanced grow out at the hatchery.
BY CAL YONCE, COLUMBIA FWCO
The Columbia Fish and Wildlife Conservation Office (FWCO) monitors Missouri River fish populations as part of the Pallid Sturgeon Population Assessment Project. Fisheries biologists use different sampling methods each field season to collect fishes in their natural habitat. During summer months, trawl, trammel and mini-fyke nets are used to catch a diversity of fish species. Each year 25 random river bends stretching from the confluence of the Mississippi River upstream to the Grand River and Missouri River confluence are sampled using these fish collection methods. Capture events often yield a variety of fish, some of which can’t be identified in the field. Such fish are preserved for future identification, genetic analysis or reference collection specimens.
Using taxonomic keys, lab equipment and scientific protocols, preserved fish are identified and recorded for input into a multi-agency database. This information can then be accessed by other fisheries biologists to update fish ranges and habitat use for reports and literature.
Employees of the Columbia FWCO take great pride in correctly identifying new specimens coming into the lab. The data collected will help fisheries managers make vital decisions in conservation for years to come and will further the understanding of this unique river system ecology. For instance, several types of minnows found in the Missouri River thrive in the same micro niche habitat as juvenile sturgeon. These minnows are usually found in higher abundance than juvenile sturgeon and quite often need to be identified in the laboratory. By monitoring population trends of minnow species biologists may be able to correlate fluctuations in sturgeon relative abundance with abundances of these minnow species, which are also a prey item for pallid sturgeon.
The effort to collect fish community data helps biologists to analyze habitats used by multiple species and the interspecies relationships found within that ecosystem.