2015 was the year of the Water Hyacinth on Clear Lake, Texas. This floating plant has been here for a number of years, but this was the first time I saw huge mats of the stuff drifting the length of the lake. I also saw several of the tributaries totally choked with it.
Water Hyacinth, or more technically Eichhornia Crassipes, is a rather beautiful invasive species brought here from the Amazon. Since it won its freedom, it has taken over countless fresh water lakes and streams in the southern United States. Florida and Louisiana have been especially hard hit. They have spent millions trying to control the hyacinth in an effort to keep their waterways navigable. Water hyacinth can be spread numerous ways, including by the bilge water of fishing boats, and accidental releases from aquariums. You could even “accidentally” spread it by purchasing it on eBay and having it shipped to your door. I don’t recommend this.
Water Hyacinth can grow faster than almost any other plant, at a rate over 10ft a day, and can double in surface area every 14 days. When it completely covers a body of water it essentially damps out all wave action, which is the principle mechanism for oxygenation of the water. As a consequence, the water becomes oxygen depleted, and many aquatic organisms, including fish, can die.
So case closed, right? Let’s kill the stuff! We could harvest it and turn it into biodiesel. Or perhaps we could use it as fertilizer or turn it into jewelry or something, I don’t know. But hold on a second. Fixing nature has never been that simple. Plus, I can think of at least one nutty reason why we might want to leave the stuff alone, and let it take over Clear Lake, at least for a few decades.
Water Hyacinth has one interesting trait. It concentrates heavy metals and pollutants within itself, and it just so happens Clear Lake is one of the most polluted bodies of water in the United States. Its main feeder, Clear Creek, is full of Dioxin and PCBs. Consuming any fish from there is strongly discouraged.
But nowadays, Clear Creek is full of water hyacinth as well. After a heavy rain, acres of the stuff tear loose and drift into Clear Lake. After a few days of soaking in the brackish water, the hyacinth turns brown and dies. I can’t say how far it eventually travels, or when it finally sinks. Some certainly makes it into Galveston Bay. It is likely that bits and pieces make it out to sea. Perhaps some even falls as marine snow in the abyssal deep of the Gulf of Mexico.
Here I claim, without proof, that the hyacinth is slowly transporting its accidental load of industrial chemicals seaward, and then depositing it where, over the centuries, sediment will effectively sequester the toxins. So this brings us to Nausicaä. It seems that just maybe, our local aquatic toxic jungle is slowly working to rid us of our past environmental sins, just as hers did. Who knows, maybe a thousand years from now Clear Lake will be clear, and our descendants will reside right here, in the Valley of the Wind.