MILWAUKEE - It's happening again. Dead fish are washing up on the shore of Lake Michigan in droves.
"Alewives are coastal marine herrings, so they're related to things like sardines," explained John Janssen, a professor at the UW-Milwaukee School of Freshwater Sciences.
They're dying off for a couple of reasons.
"They're overpopulated, there's not enough food. There's the stress of trying to spawn. Also, since they're marine fish, they evolved in saltwater, and they're much more sensitive to things like temperature change."
The fish don't pose a risk to people, but there is a word of caution to pet owners.
"If you take your dog to the beach, you're going to find out they like to roll in them because they like that kind of perfume," said Janssen.
This is not the first time the stinky creatures have piled up on the shores.
"In 1967, the population increased so much that there was a massive die-off that closed the beaches all around Lake Michigan. It got national attention."
Bulldozers even had to be called in to remove them.