Largemouth bass vs Topeka shiner

[Tim Smith]

Pasted below is the abstract of an article that points rather convincingly to the role of largemouth bass in the decline of Topeka shiners. Given the small range of Topeka shiners, it could well be argued that management for the promotion of a largemouth bass fishery in these rivers could lead to the decline and possibly the extirpation of this fish species.

 

Is this a case where a minnow is more important than a bass? Should this stream be managed for the minnow species at risk of extinction preferentially to the bass fishery?

 

Influence of Instream and Landscape-Level Factors on the Distribution of Topeka Shiners Notropis topeka in Kansas Streams

 

S. J. Schrank, C. S. Guy, M. R. Whiles, B. L. Brock

 

A. Kansas Cooperative Fish and Wildlife Research Unit, 205 Leasure Hall, Division of Biology, Kansas State University, Manhattan, Kansas 66506-3501, B. E-mail: chrisgy@ksu.edu. Send reprint requests to CSG., C. Southern Illinois University, Department of Zoology, Carbondale, Illinois 62901-6501, D. Division of Biology, Kansas State University, Manhattan, Kansas 66506-3501.

 

The Topeka shiner Notropis topeka has declined in abundance throughout its historical range in the central U.S. As a result, this minnow was listed as federally endangered in 1999. The objective of our study was to quantitatively assess instream physical, chemical, and biological parameters and landscape-level factors influencing the distribution (i.e., extant or extirpated) of Topeka shiners. We sampled 26 streams in the Flint Hills region of Kansas: 12 sites where Topeka shiners are extant; and 14 sites where they are extirpated. Multivariate analysis of variance was used to test whether variables were different between extant and extirpated sites. Mean catch per effort of largemouth bass in stream pools was higher at extirpated sites, and species diversity by trophic guild and richness in stream pools were higher at extirpated sites. Stepwise logistic regression was used to develop a model to predict whether Topeka shiners were extant or extirpated. Number of small impoundments per watershed area, catch per effort of largemouth bass Micropterus salmoides in pools, and length of pool were the only significant variables in the logistic model. Our model correctly classified 83% of extant sites and 85% of extirpated sites. In a landscape-level analysis of 111 streams, only number of small impoundments per watershed area was significant in the logistic model. These results provide predictive tools to assess instream and landscape-level characteristics for habitat management and possible reintroduction of Topeka shiners in Kansas Flint Hills streams.

 

Submitted: July 5, 2000; Accepted: November 3, 2000

[Gary L]

So in a nutshell what they found it 2000 was that the Extant strteams had an existing Topeka Shiner Population and they attribute that to a lack of Largemouth Bass. The Extirpated Streams had the Topeka Shiner Population destroyed and they attrubute that to the existance of the Largemouth Bass in various pools thru the watershed. It is a small article and can be confusing and may be that the water quality was better in the extant streams then the extirpated streams. This study was done in 2000 which was six years ago. I ask what is going on with the Topeka Shiner now. Has it migrated into the extirpated streams and repopulated them or has it remained on the declining list. I am sure other factors such as spawning sites for the shiners was part to blame. Where these manmade pools or where they natural. If manmade could they have been removed thereby providing a better future for the Topeka Shiner.

[Tim Smith]

So in a nutshell what they found it 2000 was that the Extant strteams had an existing Topeka Shiner Population and they attribute that to a lack of Largemouth Bass.

Yep. The more bass there were in the pools, and the more small impoundments were present in the watersheds, the fewer of the endangered minnow were present. It appears from the text that both species use both natural and artificial pools as habitat...certainly that's true for largemouth bass. I don't think the age of the study is of much concern. Six years is just the blink of an eye in the life of a stream. There may be other studies out there about this now, but even this study is "new" information from an ecological perspective.

 

It is a small article and can be confusing and may be that the water quality was better in the extant streams then the extirpated streams.

 

Nope. They checked and water quality wasn't a factor.

 

I am sure other factors such as spawning sites for the shiners was part to blame.

 

As you say, Gary, other things that aren't discussed here may have affected the distribution of the minnow (depth of the pool, oxygen, temperature), but there are no data available to support that view (By the way, if you're looking for bias in ecological data, that's the primary way...perhaps the only significant way...it appears. You can only find what you're looking for. That's not to imply at all that this study is malicious, it just has the limitations of every other study in the world. It doesn't have the resources to look at everything and it doesn't address the role of some other factors.). Still the data do support the hypothesis that the likely cause of the minnow's decline is that bass are eating the minnow.

 

Notice too, the bass appear to be getting into the stream from small impoundments. I would bet those are very small streams where bass would not normally survive for many years at a time. It's probably the constant re-introduction of bass from the ponds that keeps them in place (much like bluegill in small Illinois streams...bluegill are not a small river species).

 

What would be a reasonable management response? Banning largemouth stocking in impoundments where this minnow occurs (it is a Federally endangered minnow, and that's not impossible)? Largemouth bass removal from the streams?

 

How might this kind of problem affect us in Illinois? We don't have Topeka shiner, but we have quite a few other types of endangered prey species.

[Gary L]

Here is some more research on the Topeka Shiner.

Nov. 24, 2003

Contact: Scott Campbell, Kansas Biological Survey, (785) 864-1502.

 

KU research helps in effort to restore endangered Topeka shiner minnow

By Cathy Sherman

 

LAWRENCE -- Research discoveries by University of Kansas biologists are helping state and federal wildlife officials bring the endangered Topeka shiner minnow back from the brink of extinction.

 

One key was confirmation by Scott Campbell, research associate with the Kansas Biological Survey at KU, and his colleagues that the presence of sunfish in the right environments increased the minnow's natural rate of reproduction.

 

As a result, KU biologists have been able to propagate thousands of shiners for use in research from an initial stock of 300 taken from one Kansas creek and have provided them for counterparts at Kansas State University and in the Missouri Department of Conservation for their own studies of this "little-understood" fish, Campbell said.

 

The 3-inch Topeka shiner, a member of the minnow family Cyprinidae, lives about three years and is found in the calmer runs and pools in the headwaters of certain small streams in Kansas, where it's most common, as well as in limited places in Missouri, Iowa, Nebraska, South Dakota and Minnesota.

 

"In summer months males display bright red fins and iridescent bluish bodies, making them one of the more strikingly beautiful fishes in our state," Campbell said.

 

Developing techniques to propagate Topeka shiners is important to their recovery, considering that the Topeka shiner's range has declined by nearly 90 percent in the past few decades and it was added to the federal endangered species list in 1998, Campbell said. It now occurs in only a small fraction of places where it once was common and even has vanished from the Topeka creek where the first Topeka shiners to be described by biologists were identified in 1884.

 

The U.S. Fish and Wildlife Service and the Kansas Department of Wildlife and Parks funded the KBS study. The Kingsbury Family Foundation through the KU Endowment Association provided additional funding to support graduate research assistantships.

 

In the study, Campbell; Jerry deNoyelles, associate director of KBS and KU professor of ecology and evolutionary biology; and KU graduate students Cody Szuwalski and Bridgett Chapin provided a variety of habitats in a dozen experimental ponds and several large tanks at the KU Field Station and Ecological Reserves north of Lawrence to determine the shiner's ideal spawning conditions.

 

They discovered the tiny fish likes a bed of clean gravel and calm water and it reproduces much better when orange-spotted or green sunfish are present.

 

"This may at first appear counterintuitive, since the sunfish are predators known to prey on minnows such as the Topeka shiner," Campbell said. "However, and apparently in spite of this risk, Topeka shiners have been observed to dart in and lay their eggs on the nests of spawning sunfish."

 

Since sunfish fiercely guard their nests and fan them attentively with their fins to keep them silt-free and well oxygenated, perhaps the sunfish unwittingly protect not only their own eggs but also those of the interloping shiners, he said.

 

"The results of the current research confirm we are grasping the fact that in some way the sunfish confer a kind of reproductive advantage to the Topeka shiner," Campbell said. "That the shiners apparently depend on other fish species for reproduction demonstrates the importance of diversity in a fish community and provides additional evidence that nature is wondrously full of such complex relationships that humans are only beginning to appreciate.

 

"When a natural fish community becomes altered or diminished in some way and possibly loses the diversity of species that supports it, the effects can be quick and unpredictable."

 

What is happening to the Topeka shiner is an indicator of the broad-scale environmental changes that are greatly affecting aquatic communities throughout much of the Great Plains, Campbell said. Genetic diversity diminishes as species go extinct or as existing populations become increasingly isolated. Several factors seem to have contributed to the shiner's decline, including loss of habitat, diminished water quality and the wide introduction of predaceous fish, such as largemouth bass, Campbell said.

 

There's strong evidence that largemouth bass were responsible for decimating the fish community in Wallace County's Willow Creek, a harsh environment for any aquatic species in extreme western Kansas, Campbell said. Protecting the Willow Creek population is of particular interest to scientists because it exists in isolation, nearly 250 miles from other known populations, and its members are genetically different from other Topeka shiners.

 

Topeka shiners had lived in the pools of Willow Creek for perhaps thousands of years as part of an "ecologically perfect" fish community, according to Vernon Tabor, endangered species coordinator for the U.S. Fish and Wildlife Service. Tabor also serves on the National Topeka Shiner Recovery Team and is an active collaborator in KU's current research effort.

 

At least six species of minnows, two species of sunfish, a darter, black bullhead catfish and plains killifish had thrived in Willow Creek, according to regular sampling that has occurred there for more than 60 years. But after a single winter, the Topeka shiners and several other species of minnows were nearly gone. Coincidentally, largemouth bass had been introduced to the creek the previous year, Tabor said. Tabor, Campbell and others believe that introduced bass, as well as other environmental factors, may be largely responsible for the decline of wild populations of the Topeka shiner, Campbell said. Predation will be among the many new questions addressed by continuing research at KU using the stock of fish being produced at KU's field station.

 

"Across its entire range the Topeka shiner still faces a long 'upstream' battle for survival and will require the help of humans who must significantly improve habitat conditions and the water quality of our streams for all who share it," Campbell said. "However, thanks to the efforts of concerned citizens and scientific research at KU and elsewhere, the shiner's future may be getting a little brighter.

 

"People may wonder why I think saving the Topeka shiner is worth the effort," Campbell said, adding that it's more than scientific interest. "When I consider the fact that this little fish has managed to survive for countless generations, perhaps thousands of years, here on the prairie, I respect and marvel at that and take great comfort in knowing many other Kansans share that feeling as well."

[jamie shard]

Wow, it does sound like the largemouth bass is an invasive species in a sense, because it was introduced beyond its naturally occuring range in this case. I get the feeling that more folks are interested in protecting rare species and recognizing the limitations that go along with it... but I don't know for sure. What to you guys think?

 

-jamie

[Tim Smith]

Jamie,

 

You could think of those largemouth as an invader, but there have probably always been a few largemouth bass in those watersheds. The problems for the Topeka shiner started when the numbers of bass in those watersheds were cranked up to un-naturally high levels.

 

To me, this kind of study points toward the need to keep ecosystems as natural as possible and keeping our fisheries as natural as possible too. There are places where the local species are adapted to bass and places where the local species can't handle bass.

 

To us, that means when we go fishing, we're not just fishing for smallmouth. We're fishing for smallmouth in a specific ecosystem with a specific history stretching back tens of thousands of years. We want to fit into that history in a way that keeps the pieces of that ecosystem intact as much as we're able.

[Jim J]

Tim,

Sounds like the makings of a good article.