Transcript Slide 1
Marine Producers What do Producers “Do for a Living” Primary Productivity…production of organic matter by: 1. chemosynthesis- make sugars using H2S (hydrogen Sulfide) or CH4 (methane) 2. photosynthesis- make sugars using light Why is this so important? • Sun’s energy is transformed and available to other organisms • Other organisms need energy for: – Reproduction – Feeding – Metabolism By-products of Primary Productivity • Oxygen –More than ½ of the oxygen we breathe comes from marine producers primary productivity animation Where does primary productivity happen? http://oceancolor.gsfc.nasa.gov/cgi/image_archive.cgi?c=CHLOROPHYLL Requirements for Photosynthesis • Pigments, light, nutrients, and trace metals – Light is found in upper several hundred meters – Nutrients are found in deeper waters – Trace metals are limiting (not found in high amounts) Types of Marine Producers • Bacteria- Responsible for 30-50 % of marine primary productivity • Algae – (protists) groups of relatively simple living aquatic organisms that photosynthesize • Marine plants- ex. sea grasses and mangroves Marine Bacteria • Most abundant orgs on our planet • 1st photosynthetic orgs may have been cyanobacteria • Roles of bacteria – Photosynthetic * *Primary – Chemosynthetic * productivity – Decomposer www.fas.org/irp/imint/docs/rst/Sect20/A12.html http://www.noc.soton.ac.uk/chess/education/Images/Riftia_Lutz.jpg www.icm.csic.es/bio/images/mol3.jpg Types of Algae •unicellular algae “phytoplankton” •Single celled •macroalgae- “seaweed” •Multicellular Classification of Phytoplankton Kingdom…Protista 3 Groups we will focus on… Diatoms Dinoflagellates Coccolithophores Diatoms- Golden Algae •Frustule (cell wall) made of silica •Inhabit cold waters •Spines and oil droplets to stay buoyant Diatoms •When diatoms die their shell falls to the ocean bottom •fossil deposits are mined and used for filters and abrasives (beer, pools& pesticides) Diatomaceious earth Dinoflagellates- Fire Algae •Not all are autotrophic •Flagella helps control mvmt •crude eye •some are bioluminescent Eye spots for concentrating light Importance of Bioluminescence in plankton: •defense mechanism in some animals •Communication •Attract prey/mates Coccolithophores •covered in scales called coccoliths •Coccoliths are made of calcium carbonate •Important tropical phytoplankton- they like areas with low nutrient content Coccolithophores- cont • When these orgs die and settle they create deposits of chalk • Role in Carbon cyle- Use carbon in photosythesis and to make coccoliths • Produce chemical that triggers cloud formation http://earthobservatory.nasa.gov/Study/Coccoliths/bering_sea.html staffwww.fullcoll.edu/.../coccolithophore.jpg http://www-ocean.tamu.edu/Quarterdeck/QD5.2/s.apsteinii.html http://www.ucl.ac.uk/GeolSci/micropal/images/calc/calc038.gif White Cliffs of Dover cache.eb.com/eb/image?id=74594&rendTypeId=4 Harmful Algae Blooms • When nutrients are available or some physical conditions of the water are good algae can bloom out of control!!!! (you can see the blooms from space) • Eventually nutrients are used up and the algae die …decomposition uses up oxygen…can suffocate organisms in that habitat http://epod.usra.edu/archive/epodviewer.php3?oid=35104 Example: Red Tides • Rapid increases of dinoflagellates • Some produce deadly neurotoxins • Neurotoxins build up in food chain and can cause illness/ death when animals eat contaminated flesh In February 2002, the massive die-off and decay of algae from a nearshore harmful algal bloom (a "red tide") caused a rapid reduction in the water's dissolved oxygen concentration, driving tens of thousands of rock lobsters to "walk out of the sea" near the coastal town of Elands Bay in South Africa's Western Cape province. The lobsters in search of oxygen moved toward the breaking surf, but were stranded when the tide went out. Government and military staff attempted to save some of the lobsters, but others were collected for food. A similar stranding from a massive red-tide event occurred at Elands Bay in 1997. MACROALGAE http://www.ucmp.berkeley.edu/chromista/phaeophyta.html Green Algae (Chlorophyta) • Largest phylum of algae • better known as green or grassgreen algae because of its color • among the oldest of all organisms • most immediate relatives of green land plants Habitats • found on damp soil • attached to land plants • in snow and ice • on coastal rocks at low tide Examples… • Ulva Brown Algae (Phaeophyta) Structure • Multicellular • Can grow up to 180 feet • Color varies from dark brown to olive green Structure • Leathery and can withstand exposure to air • Gas-filled floats • Cell wall made of gelatin and pectin (useful in foods) • Blade: absorbs sunlight • Stipe: carries sugars from the blades to the rest of the plant • Holdfast: anchors the plant to rocks Examples • Rockweeds • Kelps Red Algae- Rhodophyta About Red Algae • • • • • • skeletons composed of CaCO3. most grow as filaments, or sheets of cells. Large group of algae Can be parasites of other algae Chlorophyll masked by red pigment Important food source: used to make nori Marine Plants Overview • Few species can live in salt water • More can take partial submergence • Evolved on land 1st , then adapted to living in saltwater • Not major players in the marine environment Halophytes- plants that thrive in salt water • 2 ways of dealing with salt: –Excluders- secreting excess salt –Includers- absorb water within large vacuole to reduce salinity (succulents) Importance to Marine Life •Primary Production •Shelter and nursery habitat •Food •Filtration of Water •Soil stability Types of Marine Plants • Angiosperms (flowering plants) • Due to the difficulty of removing salt from water entering its roots • Three main communities –Salt marshes –Mangroves –Sea grasses Salt Marsh Vegetation • Mostly grasses- Spartina, Salicornia and Juncus • Tolerate periodic submergence • Upper parts of the beach • Underground root systems • Minimized leaf structure to reduce water loss • Temperate and higher latitudes Spartina (cordgrass) Juncus (rush) Salicornia (glasswort) Mangroves • Upper part of high tide areas in tropics • Group of trees that can tolerate roots being submerged for part of a tidal cycle • Over 100 species • Thick waxy leaves to min. water loss Mangroves MANGROVES Areas that have mangroves include parts of the United States, Singapore and China - most areas that are ‘tropical’ and have warm, rainy conditions. Prop root: supports the stem Pneumatophores: grow up into air and absorb gases when tide recedes; Buttresses: stem support that adds stability in soft sediments Sea grasses • Live completely under water (shallow depths) • 40 species • Zostera (eel grass), Thalassia (turtle grass), Syringodium (manatee grass) --Adapted to live under water surface --Related to flowering plants --Produce tiny flowers --Strap-like oval leaves --Form meadows in estuaries & shallow waters with muddy bottoms