Do you live in Vancouver and are tired of paying rent?
Great news! I have just become aware of completely free housing right on the beach! There’s only one catch… you must shrink yourself to be about half an inch tall to be able to fit inside. I haven’t been able to figure this out just yet, but if you do, let me know, and we will head over to the beach to claim our new free homes inside acorn barnacles!
Ok, so acorn barnacles don’t provide free housing for us humans (yet)… but they sure do this for other intertidal organisms!
Acorn barnacles are very abundant species that live in intertidal zones of beaches (the zone between high tide and low tide) all over the world, including Vancouver. They are good competitors for space, and usually form mats of hundreds of individuals all over rocks in the intertidal zone. These mats greatly change the topography of the rocks, providing great protection and habitat for many species like sea snails and isopods (pictured below). And the best part is, the barnacles don’t ask for anything in return.
I was so taken away at the selflessness of this creature, so for my independent project I decided to learn more about how acorn barnacles provide habitat for other intertidal organisms and if some organisms preferred this type of habitat over others.
In short, I found that intertidal isopods (pictured below) actually love living on top of barnacles. Barnacle habitat seems to provide these little guys with protection from many of the scary stressors of the intertidal zone such as thermal stress, desiccation, wave action and predation. I also monitored two other organisms, sea snails and amphipods, however these two organisms did not show a preference for barnacle habitat. My thoughts are they are searching the housing market for something a little more upscale… perhaps some algae canopy.
Barnacles sure are amazing creatures for doing this for other organisms, however they are not the only ones who do! In fact, many animals in many different ecosystems create, maintain or modify habitats which benefits other species in their ecosystem. Animals who do this are very important to their ecosystems and are called “ecosystem engineers”.
Beavers and corals are two great examples of ecosystem engineers. Corals provide a framework for marine habitats that most coral-reef organisms depend on, and beavers build dams which support extensive wetland habitat and tons of species!
If you’d like to learn more about amazing ecosystem engineers, check out this video explaining why termites play such key roles as ecosystem engineers in the African savanna: https://www.youtube.com/watch?v=GhuB5V1A55A
And to learn more about the amazing acorn barnacle, read this: http://www.arkive.org/acorn-barnacle/semibalanus-balanoides/