Some green stuff has shown up on my 4 acre pond. I don't fertilize the lake, and I don't recall seeing algae blooms of this nature in previous years.

The pond is in West Central Alabama. For the past 2 weeks, temperatures have exceeded 90 degrees nearly every day. I'm wondering if this could be blue-green algae. Can anyone provide some insight on what kind of algae this is? If it is blue-green algae, is this automatically a bad thing?

Any help will be much appreciated. Here's a link to the algae pics:
http://imgur.com/gallery/TC7Jl47