One of the predictions from metabolic theory is that net primary production should increase with higher temperatures. We've been warming Stream 7 since October last year, so this is the first spring since we started the manipulation. A thick growth of an as-yet unidentified green alga is now appearing in thick patches in several areas along the warmed reach. We've never seen this before, so it could well be a response to warming. Check out Dan Nelson's photo taken last week. Click on the photo for a better look.