Smelt low, herring high in Lake Superior
Written by The Ironwood Daily Globe   
Tuesday, 12 February 2008 06:13

As smelt numbers in Lake Superior have plunged, native herring have exploded.

Fisheries biologists aren't quite sure why that has happened, but it has provided a bonanza for fishermen who like to catch herring through the ice.

Herring are also important baitfish for lake trout and other fish species.

 

The Department of Natural Resources has catch rate charts showing that in the late 1980s and early 1990s, when smelt numbers plummeted, herring rebounded dramatically.

Herring peaked around 1993, then dropped down next to nothing around 2000. Since then, however, herring have again shot up.

Mike Seider, a DNR fisheries biologist from Bayfield, discussed the fluctuating herring populations with Saxon Harbor area fishermen late last month.

"We know 1989 was a big year class for herring, but some years are busts," Seider said. "That's probably the norm for Lake Superior," he said, referring to the sporadic year classes.

While the herring population has bounced up and down like a pinball over the past decade, smelt numbers have remained very low for that entire period, showing no signs of rebounding.

"Smelt numbers are way down. Lake trout are preying on them, munching on them," Seider said.

There are more fish predators throughout the lake and that has caused growth rates of species like lake trout to decrease, Seider said.

"A typical lake trout today grows slower than it did 20 years ago," he said.

In addition, with fewer smelt in shallow water and more lake trout in the lake system, stocked salmon are having a harder time surviving.

Seider said better regulations, including fish refuges, and the control of sea lamprey have helped lake trout rebound and have a better chance of surviving to an older age, although Saxon Harbor fishermen believe excessive gill netting is working against the chance of a laker living very long.

With all of the herring in the lake, mixed with a few smelt, the DNR believes the native prey fish population is adequate to support native fish populations, however.

 
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