Oxygen Consumption in Response to Elevated Suspended Sediment Levels in Western Blacknose Dace (Rhinichthys obtusus)

Blacknose dace ( Rhinichthys obtusus) commonly found in small Midwestern streams.  Increased agricultural production to support the biofuels industry has the potential to result in higher levels of suspended sediments in these streams.  The goal of this experiment was to determine whether varied levels of suspended sediments affect the rates of oxygen consumption in western blacknose dace. We used  39 western blacknose dace incubated in custom respirometers fitted with an oxygen probe to record the dissolved oxygen levels while the trials were running. Our results indicated that western blacknose dace consumed greater amounts of oxygen under higher suspended sediment regimes.  While such increased oxygen consumption in response to heightened suspended sediment levels can be an adaptive strategy over the short term, we expect that chronic exposure associated with continued land use change would result in lowered fitness of individuals in affected streams.