Friday, July 6, 2012

Bryozoans


Looks like this little fella, given his helmet and the rest of the kit he’s toting, is from the Wehrmacht, the WWII German army. Poised, ready to shoot, a cog in Der Führer’s army. He’s been out at sea a long, long time, finally coming to rest on Kehoe Beach, far from home, far from the war.



He’s sporting a colony of distinctive honeycomb little homes, the mineralized skeletons of Bryozoans. Skeletons or houses—Bryozoans love growing on the slick surfaces of kelp and seashells. And, on the slick surfaces of plastic. In some ways Bryozoans are a “tell” of how long a particular piece of plastic has been at sea. It takes a few years to grow a good-sized colony. Not always a good time-marker, though. When the growth becomes too dense and out-weighs the buoyancy of the plastic, the piece sinks; killing the colony with deep-sea pressure and the piece bobs up again, sans Bryozoans.

Bryozoans can switch genders in a life-cycle with body parts that show that they’ve evolved to the level of complexity of earthworms. They arrived on the scene over 500,000,000 years ago and are still with us.

Bryozoa by Ernst Haeckel

Our little Wehrmacht Soldat reminds us that great armies rise and fall, but plastic could be with us as long as Bryozoans.