Mixed feelings about the news/revelation that didymo ("rock snot") can be harvested for processing into biofuel.
First of all...I have no firsthand experience with the stuff. Let's start with that disclaimer. But to me, all that's come out so far regarding the algae is overhyped fear. All we know for sure is it is generally unpleasant and is rapidly spreading into new arenas. Other than that, there isn't enough data (that I've seen) showing it to be harmful to other biota (specifically the salmonid food chain).
That said, caution is certainly warranted, and observation of posted warnings (if you've been on a stream in the northeast this past season, you've seen them) is critical to keeping the spread limited.
So now it seems it could be a blessing in disguise? I mean, hey, we have this potentially invasive species...but at least we can find a use for it? Sure, it's nice to make the best of things, but caution is also warranted in pursuing the algae as a fuel source.
What's worse...? The prospect of having our streams choked off by algae, or the prospect of having our streams mined for algae? Certainly, if it is considered a viable source of fuel, a lot of work will go into maximizing the potential yield from the organism. This means that, like many other crops, didymo would probably undergo some "engineerng" to maximize it's ability to survive, grow, and reproduce. With the evident recent twist on increasing adaptability already seen in didymo, it's a scary thought that we might be engineering a super-invasive strain in the near future.