As coral reefs continue to die from what appears to be global warming, we've had a thought-provoking series of articles in the Miami Herald over the past week. Dying reefs, habitat to all manner of delicate life, are being replaced by barrel sponges. Sponges are beating out macroalgae for space and that may be a very good thing. More resilient (obviously) than coral reefs, barrels sponges can grow to be larger than a hot tub. They filter feed on plankton and therefore attract all manner of life because they offer a source of food. Sponges also unfortunately compete with surviving coral. For space, for resources like sunlight and can, in fact, even break down dead and dying coral. Yet, less heat and acid (there's this whole business of what happens when you increase CO2 levels and shift the pH of ocean water) sensitive than coral, barrel sponges may be one of the best means for survival of the reef marine life I love. While I'm sad to think of the loss of reefs, I'm glad to think that the life that abounds in them may yet find a way to survive because of these sponges, which vary in size from thimble to that which you see below.
Image credit: J. PWLIK / UNCW
It really makes me wonder what will replace humans.