Two schools of thought
“I think there is little debate over the fact that menhaden are critical to the ecology of Chesapeake Bay, both in their filter feeding and therefore nitrogen removal and … in terms of their role as predatory fish,” Mr. Goldsborough said.
Mr. Smith said it’s hard to determine the menhaden population in the Bay.
“If Chesapeake Bay were a farm pond we might be able to answer some of the questions [Mr. Franklin] and others pose, but Chesapeake Bay is open to the ocean and the menhaden come and go in and out of the Bay,” Mr. Smith said.
One of the easiest ways to study menhaden is to study other fish in the Bay that prey on menhaden, Mr. Goldsborough said.
“Striped bass depends heavily on menhaden, with as much as 80 to 90 percent of their diet,” he said. “The percentage of menhaden in their diet has gone down tremendously, with lowest estimates at 20 percent.”
“We have all these pieces of information that are showing red flags but none of them specifically show cause and effect,” Mr. Goldsborough said.
The question of just how many menhaden are in the Bay is a $64,000 question, Mr. Smith said. “There are some research studies going on now that are trying to get at those answers,” he said.
Mr. Smith said one study uses airplanes that send low-intensity laser beams into the water to estimate the number of schools. He said this method has proved effective only in clear water and the Bay is far from clear.
“We need to manage fisheries not on a single species, but in a single ecosystem approach,” Mr. Goldsborough said.
He said the Bay’s main focus is to improve research to ensure accurate data and tools to produce clear results.
“That’s what we hope: The research will give them the tools they need to switch to these kinds of studies.”