Marine Primary Producers Macroalage & Phytoplankton Photo: C. Schvarcz (Steward Lab, UH Manoa) OCN 201 Biology Lecture 4 http://video.conncoll.edu/f/pasiv/lucid/Cyanophora-900.html Thursday, November 13, 2014 Primary production • The production of organic compounds from atmospheric or aquatic carbon dioxide, principally through the process of photosynthesis (or chemosynthesis) • Carried out by autotrophs • On land primary producers are mostly macroscopic • In the sea nearly all primary production is due to microscopic phytoplankton Thursday, November 13, 2014 Terrestrial Primary Producers Large Marine Primary Producers Macroalgae & Seagrasses Thursday, November 13, 2014 Kelp Forest Locations Macroalgae mostly limited to coastal areas Exception: Sargassum, a planktonic macroalga Thursday, November 13, 2014 BUT: most life in the sea is microscopic including the primary producers and consumers Picoeukaryote Bacterium Large Flagellate Diatom Thursday, November 13, 2014 How many phytoplankton in a liter of seawater? Bigger Diatoms 1,000 Dinoflagellates 10,000 Coccolithophores 20,000 Nanoflagellates 1,000,000 Smaller Cyanobacteria 100,000,000 very rough numbers; they vary a lot! Thursday, November 13, 2014 Prokaryotic Phytoplankton (Cyanobacteria) • Prochlorococcus • Synechococcus (and others) Responsible for a lot of the primary productivity in the open ocean Thursday, November 13, 2014 Eukaryotic Phytoplankton have Plastids that originated as symbiotic cyanobacteria Thursday, November 13, 2014 Some Eukaryotes Steal Plastids from Others This process is called kleptoplasty Thursday, November 13, 2014 Eukaryotic Phytoplankton • Picoeukaryotes • Diatoms • Dinoflagellates • Coccolithophores Thursday, November 13, 2014 Picoeukaryotes Ostreococcus - smallest free-living eukaryote By eye François Light Electron Microscope Microscope Universi Wenche Eikrem and Thursday, November 13, 2014 Picoeukaryotes Micromonas pusilla Thursday, November 13, 2014 Diatom Coccolithophore Silica frustule Calcium carbonate plates cyanobacterium Cellulose thecal plates picoeukaryote Dinoflagellates Thursday, November 13, 2014 DIATOMS Fragilaria Navicula Chaetocerous http://bioloc.oce.orst.edu/SherrLab/BESTMG9%20epi%20Chaeto.jpg Thursday, November 13, 2014 Siliceous Sediments http://www.marinebio.net/marinescience/02ocean/mgbottom.htm http://www.bhikku.net/archives/03/img/diatoms.JPG Thursday, November 13, 2014 Dinoflagellates Thursday, November 13, 2014 Emiliania huxleyi http://images.quickblogcast.com/77583-67933/coccobloom.JPG http://media-2.web.britannica.com/eb-media/94/74594-004-02A9BBFF.jpg Thursday, November 13, 2014 Summary • Kelp and sea grasses important in nearshore in nutrient rich areas BUT most primary producers are microscopic • Photosynthetic bacteria (cyanobacteria) are most abundant primary producers on the planet • The larger photosynthetic planktonic eukaryotes are also very abundant • Some important groups: diatoms & coccolithophores have hard shells that create massive (and inspirational) mineral deposits Thursday, November 13, 2014.