Reelin Realtor was kind enough to point out this recent article on the mud puppy die off occuring in the Detroit River and Lake Erie. I was witness to a large number of dead mud puppies, more than I have ever seen by far, during a trip to the Detroit River and Lake Erie on July 4th of this year. cameraguy and I came across quite a few floating across the river mouth and south, and also quite a few miles out along the north shore of Erie. By the end of the day it was... well, eerie.
Here's the link to the Detroit Free Press article by outdoor writer Eric Sharp:
http://www.freep.com/apps/pbcs.dll/article?AID=2006607230644Here's a couple of the dead mud puppies we saw - most caught in large grass mats, but some just floating along without other debris.
Mud Puppy near the river mouth

This large one was seen 3 or 4 miles out along the north shore of Lake Erie

It almost seemed like every grass mat had at least one dead mud puppy on it. The possible causes of this latest die off are very troubling. There is also more info in the article on why so many fish around the SE Great Lakes died off. I still need to look into some more remote fish kills/die offs.