Interesting

http://www.newsnet5.com/d...ada-shore-of-lake-erie

i saw another artile sawing it was sheepshead, carp, and cats
 

This happened about a month and a half ago around north east.  They chalked it up to the lake flippping.  It was mostly sheephead with some smallies mixed in.

WOW did anyone read the posts at the bottom of the article? 
 THIS COULD BE THE BEGINNING OF THE END

well if the lake flipped it could've released a methane gas pocket and the gulls thinking to get an easy meal just suffocated but methane disperses quickly being that it is lighter than air also tasteless and scentless

I blame Obama

A single large release of sewage or manure would not have caused an immediate fish kill along 25 miles of shoreline.  Sewage kills by depleting oxygen through biological reactions, not by contact. 
 
However, it would be reasonable to say that continuous discharges of sewage (or fertilizers, industrial outfalls, AG runoff, ect. ) over a period of time could have substantially elevated nutrient levels, which would have stimulated algae growth in the lake.  As summer winds down the algae dies and falls to the bottom of the lake, where it will then decompose.  The decomposition process can significantly deplete oxygen in the bottom layer of the lake.  When the lake stratifies in the early fall, this layer of oxygen depleted water is introduced into formerly oxygen rich surface waters and a potential fish kill can ensue.    
 
That is just my (un)educated guess as to what happened... 
 
 

Right, oxygen levels are naturally low below the thermocline because in general, there is insufficient light for photosynthesis to occur.  There is also little or no mixing occuring with oxygen rich waters above the thermocline throughout the summer.
 
And again you are right, this process can be natural, but there is a strong correlation between nutrient (organic) levels and the rate of oxygen depletion below the thermocline, in which the rate of oxygen depletion increases with a corresponding increase in nutrient loading.  In Lake Erie's (and many other large lakes) case it is very well documented that man has substantially accelerated nutrient enrichment into the lake. 
 
 

A toxic algae bloom could cause the rapid kill off of fish as well as the gulls, if they were breathing it in or eating dead fish that were covered with the algae.  This is the time of the year for that to happen.
 
http://www.lakescientist.com/learn-about-lakes/water-quality/harmful-algal-blooms.html

While greatly improved environmentally. The great lakes no doubt still contain numerous "timebombs" on, or within their bottoms.

ROCKSNOT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I didn't even look at the article but did they test the gull for lead? Seems a lot of rabbits and squirrel used to die from that around my neck of the woods....WF