Lake Huron Alewives Down

Many years ago my grandmother and I pulled our rakes in the wet sand of Lake Huron's shoreline to remove layers of dead alewives. I was a boy and R.C. Cola was ten cents a bottle, gasoline was under 20 cents a gallon, Viet Nam was barely on anyone's radar and dead alewives lay thick on Lake Huron's beaches.

The dead fish lay where the waves had left them like a silvery necklace that encircled an uneven shoreline. The fish sometimes lay two feet wide and were three inches thick.
But as always, times change. The dead alewives that were a nuisance and needed to be removed from beaches forty years ago have had their numbers drastically reduced. Some experts say by as much as 83 percent. There are no dead alewives on the beaches of Lake Huron now and very few in the stomachs of salmon or lake trout.

Alewives are an exotic (non-native) fish that was introduced into the Great Lakes in the mid 1900's. At that time few fish preyed on the little silver smelt-like fish, and its numbers sky rocketed. It became a rotting nuisance as thousand upon thousand of dead alewives washed upon shorelines.

After much discussion on how to deal with the problem, an idea was spawned.

The DNR would introduce a voracious predator to control alewife numbers. It was, of course, the salmon. In addition to a predator controlling an out of control prey base, the strong and fast swimming fish would add an exciting challenge for fishermen.

A new era began. In the 70's and 80's, fishermen traded their sixteen-foot perch fishing boats for 20 and 30 foot salmon trolling boats and the chase was on. Early salmon fishing was very good and some of the top fish weighed in at over forty pounds. Their stomachs were filled with a seemingly unending supply of alewives. But as years passed the average size of the fish decreased until current day when a 20-pound fish is found to be outstanding.

And this year fishermen are asking more than ever, why smaller and fewer salmon?

What's Happening

with the Salmon?

The quick answer is not enough food. The balance between predator and prey has been tipped in favor of the predator.

Dave Fielder, a fisheries biologist for Lake Huron, said, "Alewives are the most used food for salmon and that base has been drastically diminished in Lake Huron."

What's Happening

with the Salmon?

The quick answer is not enough food. The balance between predator and prey has been tipped in favor of the predator.

Dave Fielder, a fisheries biologist for Lake Huron, said, "Alewives are the most used food for salmon and that base has been drastically diminished in Lake Huron."

Outdoors with Oz

by Rick Asmus

How Come Fewer Alewives?

I called and spoke with Jeff Schaeffer who is a fisheries biologist for the United States Fisheries and Wildlife Service. His job is the study of Lake Huron's forage base. Every spring and fall, with the aid of a trawler, he goes into Lake Huron to record alewive recruitment as well as other forage base information.

"Basically the loss of alewives has been a function of the weather," noted Jeff.

Lake Huron is the northern limit for alewives and the last two winters have been very cold and extremely hard on alewives.

Alewives are born in the summer. And completed studies have shown that hatches for 2002 and 2003 were very good. However each of the studies the following spring revealed a drastic drop off in surviving young for those year classes.

"There has been minimal recruitment of alewives in the last two years, there are very few one and two year old alewives," said Jeff.

More Factors in Alewive Decline

In addition to a diminishing food base, there has been an increase in predators. Fish plantings have continued at about the same pace as usual but a new phenomenon is happening in Lake Huron. In the last few years fisheries biologists have learned that salmon are reproducing naturally.

In a perfect world, the prey and predators are in balance and that is exactly the strategy the DNR attempts to employ in Lake Huron. However, with newly realized natural reproduction of salmon there are even more mouths to feed than were originally estimated. More mouths and less food.

The Future?

"The earliest relief for this food (situation) would be this fall," said Jeff.

That's when this season's hatch would be available in the food chain. There may also be an increase in salmon fishing as they stage to make their annual fall spawning run.

"As fish move to spawn it may get better," noted Schaeffer.

But what can be done at this point?

"There's not much that can be done in the short term. Whatever we do would take a couple of years. And then it might not work," he added.