Some undergo alternation of generations, with
life histories so intricate that different stages have been described
as separate organisms. Phytoplankton come in a rainbow of colors due to their many different pigments systems, and some are
bioluminescent. They absorb and scatter light, and release a
variety of dissolved organic substances into the surrounding
water. A few produce potent toxins, and are implicated in harmful
algal blooms (HABs)