By Ed Britton
The Clinton Herald
---- — The Mississippi River’s spring pulse is upon us, bringing both good and bad news. Flooding has been tempered by slow snow melt in the north. Flooding has benefits in that it removes trash that litters the shoreline and either pushes it a little higher on the shore or sends it to our neighbors down south. Extended periods of high water contribute to increased sedimentation and filling in of backwaters, which is a chronic problem in our area.
The spring high water provides perfect conditions for Asian carp, bigheads and silvers, to migrate upriver. These Asian invaders escaped from Arkansas fish farms in the 1970s and began their trek north, south, east and west. They compete directly with our native fish in their diet of phytoplankton and have taken over much of the Illinois River fishery. There have been infrequent reports of Asian carp this far north on the Mississippi River. However, in April, a 36- inch, 21-pound silver carp was caught in Dubuque and in a nearby area Asian carp eggs and embryos were discovered. A 73-pound bighead was caught in Sabula Lake in June 2012. Monster bigheads can weigh 90 pounds and measure 60 inches long.
Silver carp are the notorious flying fish that leap from the water in large numbers when a passing boat’s motor excites them. Accidents with humans are common when boaters, skiers, and tubers are hit by the flying fish. Two underwater electric barriers span the Sanitary Ship Canal near Chicago and emit shock waves to keep these invasive carp from entering Lake Michigan and impacting the multi-million dollar fishing industry.
The great white trawlers, American white pelicans, have returned in large numbers and grace the shorelines and skylines with their synchronized swimming and aerial acrobatics. They arrived on the trailing edge of ice, taking advantage of cold water temperatures to scoop up slow moving fish. The pelicans are nesting on several island sandy beaches located north of Clinton in Pool 13. They are joined by their colonial nesting buddies, great blue herons, great egrets and double-crested cormorants. These islands are the only known white pelican nesting colonies on the Upper Mississippi River.
You can watch the daily activities of a pelican nesting colony on the live streaming Internet video webcam at the Stewards of Upper Mississippi River Refuge website: www. stewardsumrr.org. It is a busy time on the island and the antics of the pelicans are entertaining. The pelicans are expanding their nesting territories to other sandy beaches, which puts them in conflict with people who also want to enjoy the beach. Please avoid the beaches where pelican nesting colonies are present because minimal disturbance may result in colony abandonment.
The Stewards live streaming Internet webcam also features a peregrine falcon nest box that is located atop the Consolidated Grain and Barge Company’s grain elevator in Savanna Ill. A clutch of five eggs is being incubated that will make for a busy time for the parents.
Sandhill cranes are also nesting but still haven’t figured out the spring pulse of the river. They nest in shallow water areas with minimal nest materials to keep the eggs dry. The spring high water has once again flooded several nests. The Midwest Crane Count was conducted on April 12 in association with the International Crane Foundation and 10-12 pairs of sandhills are in the area.
Bald eagle nesting is also in full swing. The Upper Mississippi River National Wildlife and Fish Refuge is an important bald eagle concentration area with thousands of eagles in winter and hundreds of nests in spring. In 2013, there were 311 active bald eagle nests on the Refuge. With the increase in number of nests, bald eagles are moving farther away from the Mississippi River and in close proximity to people.
Ed Britton is a wildlife refuge manager on Upper Mississippi River National Wildlife and Fish Refuge and volunteer at Bickelhaupt Arboretum.