Tolerance of the invasive marine alga Caulerpa taxifolia to burial by sediment

Beds of the invasive alga Caulerpa taxifolia were observed to be buried with sediment after heavy rainfall, and it was proposed that burial and subsequent uncovering could help explain rapid changes in the sizes of beds of C. taxifolia. Responses of C. taxifolia fragments to the different extents of burial and for different durations (2, 6, 17 days) were investigated in the laboratory. Once uncovered, fragments in all treatments began to grow, and by 92 days partially buried fragments were not significantly different from controls in terms of the numbers of stolon meristems or total stolon length. Fragments buried totally were severely affected, but nevertheless, 35% of the fragments survived total burial for 17 days, and began to recover slowly when the sediment was removed. C. taxifolia can, therefore, persist for long periods under sediments, meaning that, in areas where burial is likely, the actual distribution of the species may be underestimated. Moreover, any potential control technique needs to penetrate sediments to be totally effective.