Kansas has two distinct fish communities, one that inhabits our big, murky rivers and another that lives in shallow, clear tree-lined streams.
Big river fish like the Longnose Gar, Blue Catfish, and Shovelnose Sturgeon have adapted to deal with murky water, so they tend to have small eyes. While they don't rely much on sight to catch their prey they do have some amazing senses that can be used even in the murkiest of water-- they can sense motion with their lateral line organs, or "smell" their prey with chemical sensors on barbels, as do catfish and sturgeon.
Drawings courtesy of Joesph Tomelleri
In contrast, fish that live in clear streams are often quite colorful during the breeding season and use their large eyes to find prey and mates.
Topeka Shiners and Hornyhead Chubs are examples of fish that were once widespread in Kansas streams. These fish lay their eggs on clean gravel, and have difficulties when the gravel gets silty due to agricultural or urban activities. They are also very susceptible to large predators which are often stocked in reservoirs and ponds.
Photographs by Garold Sneegas and Konrad Schmidt
With 116 native species, Kansas has more species of fish than any state west or north of us. The Kansas River is part of the Missouri-Mississippi River system, which has the largest number of fish species of any temperate zone river in the world (375), many of which are unique and found nowhere else in the world.
Source: Frank Cross and Joe Collins (1995) Fishes in Kansas, Univeristy of Kansas Natural History Museum; Peter Moyle and Joseph Cech, Jr. (2000) Fishes, An Introduction to Ichthyology, Prentice Hall.
This map indicates that the number of species of fish in our watersheds has been declining at an alarming rate. Compared to 1970, watersheds in our area have lost an average of six to ten species, putting us in the top 20% of the watersheds for fish species declines nationally.
Source: Map link
Unfortunately our rich fish fauna is undergoing a severe reduction. Fifteen species of fish are currently listed on the Kansas state Threatened and Endangered Speices list, an additonal 31 are listed on the state's list of Species In Need Of Conservation (SINC) and six are no longer found in the state.
The current situation may actually be even worse than is indicated by the official state lists. According to an extensive review of the status of native fish in Kansas,we have recently lost another species, the Arkansas River Shiner, and are in danger of losing an additional eight species which do not currently have viable breeding populations in the state.
Source: Haslouer, S.C., M.E. Eberle, D.R. Edds, K.B. Gido, C.S. Mammoliti, J.R. Triplett, J.T. Collins, D.A. Distler, D.G. Huggins and W.J. Stark. 2005. Current status of native fish species in Kansas. Transactions of the Kansas Academy of Science 108: 32-46.
This survey also concludes that seventeen fish species that were previously unlisted should be considered for protection, and 28 out of 37 species that are already listed as Threatened, Endangered, or Species In Need of Conservation in Kansas should have their status elevated (for example, from SINC to Threatened, or from Threatened to Endangered).This means that 47% of the fish species in Kansas may either be already extinct or in need of protection because of declining population sizes and geographical ranges.
The reasons so many fish are in trouble are related to the huge changes that have been made in the streams and river systems of the state. Dam building to reduce flooding reduces the high flow signals that some species need to trigger breeding. It also reduces the amount of habitat available during peak flows and limits the amount of food that is washed in when side channels, ephemeral streams, and high water channels are suddenly inundated and connected up to the mainstem of the river. Agricultural practices and urban and suburban construction increase the amount of silt in streams, suffocating the eggs of bottom nesting fish and reducing populations of food organisms which would normally live in between rocks and gravel on the bottom.
On the list are a number of big river fish. Sturgeon and Blue Catfish reside in the main channel of the Kaw, and are likely to be negatively impacted by dams which modify flow regimes and prevent them from moving up and down the Kaw and its major tributaries.
There are a number of barriers to fish movement which fragment populations, prevent individual fish from moving up and down the river system, cut off movement during droughts, and prevent the repopulation of regions that have experienced local population declines.
By reducing the amount of suspended sediment in large rivers, damming may also improve the ability of sight feeding predators like Largemouth Bass to capture minnows and other small fish. Bass have a very different diet and mode of hunting than Channel Catfish and other native large river predators, as you can see by comparing them-- catfish depend on tactile and chemical senses to find insect larvae and other types of food organisms that live on the river's bottom, while adult bass are visual feeders that eat higher on the food chain, taking small fish that live in the water column. As the water in the Kaw becomes less murky during low water periods, small fish become more vulnerable to predation.
Drawings courtesy of Joesph Tomelleri
Many of the small stream fish that are on the list for elevated conservation status are being harmed by increased siltation and dewatering of streams. The "manmade droughts" that are occurring because of excessive groundwater pumping are literally drying up streams in parts of Kansas, decimating populations of stream fish and other organisms.
Photo by Konrad Schmidt; courtesy of KDWP
The streams of southeastern Kansas are unusally diverse, with many Ozarkian fish species found nowhere else in the state. The fish in this region are being particularly hard hit by development.