Part of the problem with chemical herbicides is that many people don’t think through the additional problems that can occur after using them. Case in point: Biomass issues. If you read our recent post about Water Hyacinth, you may have been shocked to read that an acre of the plant can weigh as much as 200 tons! That’s a huge amount of biomass. Now, let’s say you spray a chemical herbicide on the plants and it kills them. They’re dead, but not gone. In other words, now you have hundreds of tons of dead plants in the water. The rapid decay of so much plant matter in the water causes a spike in nutrients such as nitrogen and phosphorous that make the body of water vulnerable to other kinds of plant invasions of both native (such as Starry Stonewort, Duckweed and Cattails) and non-native species (such as Water Chestnut). Furthermore, all that decaying plant matter sucks up a lot of the available oxygen in the water, which can contribute to the die-off of fish and other aquatic animals. Chemical treatments don’t remove the biomass, thereby creating a viscous cycle of nutrient spikes and further water weed invasions. Mechanical harvesting, on the other hand, is all about actually removing the plants from the water, thereby getting rid of the biomass. If you don’t physically remove the biomass, your problems won’t go away and will probably get even worse.