Probing Ocean Depths: Photosynthetic bacteria bare their DNA

Scientists call it the invisible forest, the immense mass of ocean-dwelling micro-organisms–algae, bacteria, and plants known as phytoplankton–that perform photosynthesis as trees do. Converting light, water, and carbon dioxide into energy, these microbes produce nearly the same amount of oxygen worldwide as land plants do and influence the climate by sequestering carbon inside the oceans.