Fragmentation

Fragmentation is the reproduction strategy of many submerged aquatic invasives — hydrilla, Eurasian milfoil, parrot feather. A stem fragment as small as a quarter inch can root and form a new plant within 5–10 days. A single boat-prop pass through an infested bed scatters dozens of viable fragments. This is why mechanical methods that cut without collecting can spread these species; harvesters that cut and immediately remove biomass do not have this problem.