I live on an inland lake. We had a fish kill due to golden algae.?

Question

How do seagulls and pelicans know to come from the coast to eat the dead fish? We had thousands of them.

Answer 1

First, they may not have to come as far as you think. Gulls have a WIDE range of habitat, not just the coastline. And it is the smell that draws them -- they are amazingly sensitive to smells. Check the link below for a RANGE map for just one species of gull -- it is pretty much all over the US.
http://www.nenature.com/RingBilledGull.htm

As for the pelicans, their range is shown here -- and notice that the migration area is quite wide-spread.
http://www.startribune.com/10072/rich_media/879442.html

And, gulls, apparently, are quite willing to commute for food:
"To exploit choice food sources such as landfills, however, a certain segment of the population was willing to commute great distances, and even a 50 mile round trip was routine. "
http://www.mass.gov/czm/coastlines/2004-2005/habitat/gulls.htm

Answer 2

Well a fly can "smell" something dead from over a mile away. Air carries smell a long way.

Also, there are inland gulls. So, there could be some clue sharing. Other animals know when another species has found something that might be of interest to it.

The algae is not the source of the fish kill. Oxygen depletion cause by the explosive growth or the sudden death or a combination of both, of those algae would be the real cause of a fish kill.