Biosensor it affects marine organisms, especially plankton (floating microorganisms) and viruses that attack plankton. Plankton form the base of the marine food chains and are believed to affect our planet's temperature and weather by uptake of CO for photosynthesis. Deneb Karentz, a researcher at the Laboratory of Radio-biology and Environmental Health (University of California, San Francisco) has devised a simple method for measuring ultraviolet penetration and intensity. Working in the Antarctic Ocean, she submerged to various depths thin plastic bags containing special strains of "E. coli" that are almost totally unable to repair ultraviolet radiation damage to their DNA. Bacterial death
Harmful algal bloom Not all algal blooms are harmful, however, with some only discoloring water, producing a smelly odor, or adding a bad taste to the water. Unfortunately, it is not possible to tell if a bloom is harmful from just appearances, since sampling and microscopic examination is required. There are three main types of algae which can form into harmful algal blooms: cyanobacteria, dinoflagellates and diatoms. All three are made up of microscopic floating organisms which, like plants, can create their own food from sunlight by means of photosynthesis. That ability makes them an essential part of the food web for small