Monday, October 13, 2014

Can Water Hyacinth Navigate? Should We Copy It?

The Weed from Hell. Can it Navigate?
I spend a lot of time in the California Delta, near the convergence of the Sacramento and San Joaquin rivers that drain the Central Valley. The Delta is, to me at least, an almost overwhelmingly complex ecosystem, chopped and sliced by the Army Corps of Engineers' extensive and aging levee system. Over the last 15 or so years, I've fished and hunted there and have seen many large scale environmental changes and fluctuations- mostly degradation- and it remains a source of fascination and ultimately concern, as we keep tinkering with the balance between uses and nature, all exacerbated by the increasing urgency of California's water situation, to potentially catastrophic ends.

The Delta I know best, the area around Frank's Tract, Big Break, and Sherman Island, is characterized by a very complex system of currents and tides. Tides can approach 4 feet at times, and they impact the direction of currents in the many main channels and back channels in a way that takes several decades to learn fully. After all my time out there, I'm only just beginning to develop a rudimentary sense of optimal tide and current conditions for fishing.

In summer months, water temperatures get well above 70 F, ideal conditions for invasive species like the water hyacinth (Eichhornia crassipes). I'm not sure of this, but one of the changes I think I've seen lately is a big increase in the amount of hyacinth. This could be linked to increased nitrate levels in water, perhaps exacerbated by the drought. At this time of year, water temperatures begin slowly dropping - this leads to a massive mobilization of hyacinth. Massive rafts of it can be seen wandering around on the water, seeking better growing conditions. Some of these clumps take on the size of small islands, and in low light conditions may easily be mistaken for them. On a boat you have to weave in and out of them frequently to avoid fouling your prop or worse. 

On a recent perfect Delta autumn day I was wandering around on the water myself, in my boat, looking for concentrations of striped bass (another famous non-native species common in the Delta) to tempt with a fly rod. I was parked at the corner of Potato Slough, on the main channel of the San Joaquin. While mechanically casting out and stripping in my line, I had occasion to contemplate the ubiquitous and vigorous hyacinth, which seems to be on a perpetual campaign to take over the known universe, evidencing very much the kind of will to survive at all costs that Charles Darwin apprehended so well. Having just read his On the Origin of Species, narrated by Richard Dawkins (highly recommend!), my mind was on this topic. The hyacinths seemed to be exhibiting an uncanny ability to move deliberately, something that few plants can do. They appeared to almost be "intelligent" about it, optimally using winds and current to end up, for a minute or a day or a month, in better growing conditions. 

Remembering a recent article about plant neurobiology by Michael Pollan, I suddenly thought "what if they're actually navigating? Or even communicating with each other while they're doing it?" If plants evidence neurobiological structures, as they appear to, then wouldn't a species like hyacinth (which seems to be like aspens, less a collection of individual plants than a single pulsating, maddeningly recombining organism) be able to move their roots and leaves slightly in order to harness wind and currents to drive them to water and conditions most suitable to growth? And thinking of Darwin, most certainly this adaptive behavior would have genetic roots. What if we were able to tease these genes out and use them for something else? Or if we were applying biomimetic design to something, say mechanisms for water treatment plants, how would we use this inspiration from nature? 

Or should we? Biomimicry likes to find examples from local environments as inspirations for design strategies. A good example is the design for the renovation of the San Francisco Mint, an elegant and beautiful project by the architecture firm HOK. I saw a recent presentation by HOK's Director of Design, Paul Woolford, who managed the project. Local species that inspired ideas for building systems- lighting, ventilation, thermal performance, and balance- included the California Brown Pelican, the spookfish (a new one for me), the Picasso Sponge, and the native California Salmon (I'm definitely familiar with that one!).

So here's a strange question- should we use biomimetic strategies from invasive species, like the hyacinth? Are there ethical or design issues here? According to the National Ocean Service an invasive species is " organism that causes ecological or economic harm in a new environment where it is not native." The key concepts here are "harm" and "native." Given the context, there may be a crucial difference between perceived economic harm and environmental harm. And the paradigm of perfection for species is whether they are "native" or not- we think of the salmon as more noble than the striped bass because it's more native. This kind of emotional mindset drives a lot of environmental policy. Ideally, things that are good for the environment should be good for the economy of humans too- as Janine Benyus is fond of saying "We are nature too." 

We're also the ultimate invasive species, so why don't we admire the scrappy and voracious water hyacinth and striped bass? Darwin had a lot to say about what was not then termed "invasive" species, there's a nice breakdown on that here. My sense is that he would be appropriately dispassionate about this, although in his time the massive invasions had not yet occurred on the scale we're seeing today, with the extensive systems of conveyance (global trade with ships and airplanes) we've given invasive species. 

Biomimicry is a powerful design tool that is a rich source of ideas from evolution. It didn't occur to me to bring ethical considerations into its use until I contemplated the irritating and rather terrifying water hyacinth, which, like kudzu and others like it, seems unstoppable. How might we go about learning from even plants and other creatures that are repellent to us? I'd love to hear from the Biomimicry folks on this.


  1. Tom Friedman in Sunday's NYT uses the invasive species metaphor to discuss the Islamic State guys.

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