Holoplankton—the species which live as plankton for their whole life span—are often eminent in marine food webs. A large amount of holoplankton are phytoplanktonic, namely diatoms and dinoflagellates, though there are still some which are zooplanktonic, such as copepods (Anderson). Focusing on the holoplanktonic phytoplankters, diatoms are known for being “the most productive photosynthetic [plankton] organisms” (Garrison and Ellis 400), and are a prevalent form of phytoplankton. Due to both of these factors, diatoms provide a notable amount of oxygen consumed by other marine animals and even Earth’s atmosphere; this is generally what determines them as part of the first stage of a food web. Genevieve Anderson, a Santa Barbara City College marine scientist, considers dinoflagellates as both producers and consumers, as “they could both photosynthesize and ingest organic material.” She also notes that dinoflagellates “are seasonally abundant and are one of the primary causes of red tides, seawater bioluminescence, and shellfish poisoning” (Anderson).