Blackbird Marsh, located just south of Interstate 29 at the north end of Council Bluffs, is a common landmark to many area residents. This marsh area is home to many species of water birds, mammals, amphibians, & of course fish. Recently, passers by have noted a large number of deceased fish, the result of an unfortunate event called a "fish kill".
Fish kills happen in area waters for two primary reasons. The first is a natural occurrence, due to warm temperatures or decreasing oxygen levels in the water. The second is due to outside causes, such as chemical runoff. Pottawattamie Conservation staff has worked with the Iowa Department of Natural Resources Environmental Services Division to conclude this year's fish kill was a natural occurrence & not due to any foul play or chemical dumping.
Typically fish populations in this area are small due to its landlocked location but due to flooding in recent years the population has increased. Fish, particularly river carp, have been transplanted in the rising floodwaters & then left behind in the marsh when waters recede. The increased fish population combined with this year's low water levels & warm late summer weather combined to reduce the amount of oxygen in the marsh waters to a low level incapable of supporting the existing fish population.
While this event is regrettable it is a natural occurrence. Scavenging animals will soon dispose of the remaining fish but until then you may spot deceased fish on the surface of the water as you travel along that stretch of road.
Please call 712-328-5638 if you have any additional questions regarding the Blackbird Marsh fish kill.Next Blog
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