Sites and Critters

The aesthetic delight of Aurelia aurelia

A quick tribute to a common urban marine organism that I think is particularly beautiful: the Moon Jelly, Aurelia aurelia. Here’s a video I took recently of one in Seattle’s Elliott Bay:

Jellyfish have probably been a source of inspiration for artists and designers for as long as humans and jellies have coexisted (ie – all of human history; jellyfish have been around from some 500 million years or more). They’ve served as study subjects for all sorts of work, from Ernst Haeckel’s lithographic prints to Dale Chihuly’s organic glass forms. In Björk’s current exhibit at MOMA, she explains that the ancient, pulsing, fleshy creatures connote feelings of calmness and satiation that come with finding love (though it seems jellyfish imagery has had other uses in her work as well: link). Others seem captivated by the silent, toxic danger jellyfish pose to their prey, or simply by their beautiful, primal form and the aesthetic experience of observing them in their environment.

Beyond artistic expressions past, jellyfish might also provide inspiration for technological innovations of the future. Could knowledge of the way in which Aurelia propels itself help us develop more efficient forms of underwater propulsion or better medical technologies? John Dabiri at Cal Tech believes so. Or perhaps the peculiar qualities and molecular structure of jellyfish tissues could facilitate advances in material sciences, as noted by Steven Vogel in Comparative Biomechanics.

As coastal ecosystems become ever more urbanized and the planet undergoes rapid changes, we may need to look to nature for examples of physical designs that are tried and true. Few organisms have the track record of jellyfish, with 500 million years of adaptation and counting. What luck that they’re aesthetically endowed too.

Recent Research

Could jellyfish blooms be attributed to “ocean sprawl”?

Photo of Jellyfish by Ole Kils

Image by Ole Kils

You may have heard that jellyfish are taking over the world’s oceans, proliferating at a rate that is unfounded by historical standards.  Is it possible that this has been facilitated by the urbanization of coastal ecosystems?

This is the question posed by Carlos Duarte and colleagues in a recent a paper published in Frontiers in Ecology and the Environment (link). Many jellyfish have two life stages: the pelagic, medusoid phase that probably comes to mind when you think of jellyfish, and a juvenile stage in which they are attached to the bottom as tiny polyps. Most previous studies that have tried to explain recent increases in jellyfish abundance have focused on the pelagic stage.  Tiny polyps are hard to find, and have thus not been a central focus for research.

That is until now… Duarte and colleagues searched far and wide for the tiny creatures.  Where did they eventually find them? On the underside of floating docks, buoys, riprap and other artificial structures. They suggest that the proliferation of artificial structures (which they identify as “ocean sprawl”) is precisely what has allowed jellyfish populations to explode.

Many questions remain, of course, and much more must be done to see if their theory holds water. While Duarte et al. found that jellyfish polyps of some species favor shaded habitats, has the increase in shaded habitat associated with “ocean sprawl” really been sufficient to facilitate the types of increases we’ve seen in adult jellyfish populations? Does the trend extend to species they have yet to test experimentally? And can we actually find these polyps on our local floating docks prior to jellyfish blooms? All of this remains to be seen.