A new study suggests if bighead and silver carp were to invade Lake Erie, the fish biomass would remain relatively unchanged.
Since 1995 at least three bighead carp have been found in the lake, but there is no evidence of them being established there, the University of Notre Dame reported. The findings were published in a recent edition of the journal Conservation Biology.
"Bighead and silver carp will continue to have access to the Great Lakes - it is important to understand what the consequences could be if they were to establish," said Marion Wittmann, the paper's lead author and University of Notre Dame scientist.
To estimate the potential impact carp would have on the lake's biomass researchers used expert elicitation ("a process of formalizing and quantifying experts' judgments.") A team of 11 experts determined if bigheaded and silver carp were established in the lake they would not exceed a biomass of 25 metric-tons per square kilometer, which is greater than the walleye and yellow perch biomass.
The team estimated the event would not reduce Erie's yellow perch biomass; the biomass could even increase by up to 50 percent. If carp became established the walleye biomass would most likely take a small hit and decline by about 10 percent, but the researchers were uncertain in this estimation. They also suggested walleye biomass could decrease by as much as 40 percent or increase up to 60 percent.
"This study uses the knowledge of the foremost Great Lakes and Asian carp experts in the field to help us understand what the impact to Lake Erie fisheries biomass may be," said David Lodge, director of the University of Notre Dame's Environmental Change Initiative and co-author. "But it does not estimate all the other damages potentially caused by bighead and silver carp such as those that may occur in tributaries of Lake Erie, or effects to recreational activities as a result of silver carp jumping behavior."