Post on 01-Jan-2016
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Primary Productivity…production of organic matter by: 1.chemosynthesis- make sugars using H2S (hydrogen Sulfide) or CH4 (methane)
2. photosynthesis- make sugars using light
What is Primary Production
Importance to Food Web
• Sun’s energy (or chemical energy) is transformed and available to other organisms through the food web
• Primary production is base of food chain– Other organisms need energy for:
• Heat• Reproduction• Feeding• Metabolism
Other Benefits of Primary Production
• Oxygen– More than ½ of the oxygen we breathe comes from
photosynthetic marine producers• Shelter and nursery habitat
– Baby fish and inverts can hide among roots of marine plants in estuaries and bays
• Filtration of water– Marine plant roots trap particles and pollution preventing it
from entering oceans• Soil stability
– Roots hold soil and sand in place and prevent erosion
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Where does primary productivity happen? List 2
general locations…
http://oceancolor.gsfc.nasa.gov/cgi/image_archive.cgi?c=CHLOROPHYLL
Requirements for Photosynthesis
• Light– Pigments harness light energy in photosynthetic
reactions to convert CO2 into glucose.– Light is found in upper several hundred meters
• Nutrients and trace metals– Nutrients and trace metals like iron are limiting – Needed to make new plant tissue and do
photosynthesis– Nutrients are replaced by upwelling. Iron is
replenished by upwelling and atmospheric deposits
Marine Bacteria
- Responsible for 30-50 % of marine primary productivity
- First life on the planet with fossils as old as 3.8 my old
Chemosynthetic Bacteria
• Release energy stored in compounds like H2S , CH4 or NH3
• Base of the food web in places like hydrothermal vent communities and methane seep communities found in the deep ocean
Photosynthetic Bacteria
• Contain chlorophyll like green plants and use light energy to make organic compounds
• Cyanobacteria- blue green photosynthetic algae– First ps orgs on our planet– Played a role in accumulation of O in the
atmosphere
Other Bacterial Roles
• Bacteria carry out important roles as heterotrophs and decomposers– Ensure recycling of essential nutrients– Found everywhere in ocean from ocean surface
to deep ocean sediments– Bacterial decomposition of dying plankton
blooms linked to cloud formation and climate
Marine Protists• Algae – (protists) groups of relatively
simple living aquatic organisms that photosynthesize
• Lack specialized tissue found in plants•unicellular algae “phytoplankton”
•Single celled•macroalgae- “seaweed”
•Multicellular
Phytoplankton
• Oil droplets and spines help keep phytoplankton afloat in sunlit areas of ocean– Oil is possible energy source for us!
• Some have primitive eyespots for concentrating light
• Many have cell walls
Dinoflagellates- Fire Algae
• Some are bioluminescent
• Two flagella for mobility
• Zooxanthellae- specific symbiotic dinos that live with other animals like anemones, coral and giant clams– In coral they fix CO2 and help in forming coral
skeleton
Coccolithophores
• Covered in plates of calcium carbonate– Shells cover large portion of ocean floor
(1000’s of meters thick in some places)– Important in trapping carbon in the deep
ocean
• Do well in nutrient poor and low sunlight conditions
• Produce DMS- a chemical linked to cloud formation
staffwww.fullcoll.edu/.../coccolithophore.jpg
http://www.ucl.ac.uk/GeolSci/micropal/images/calc/calc038.gifhttp://www-ocean.tamu.edu/Quarterdeck/QD5.2/s.apsteinii.html
Diatoms
• Cell walls made of silica
• Glassy frustules deposit on ocean floor and cause thick deposits of diotomaceous ooze– Mined for human use
• Important in open water primary productivity
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
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
Seaweed
• More complex than phytoplankton but still less complex than plants
• Entire body of a seaweed is called the thallus
• Three types of seaweeds based somewhat on pigment color– Chlorophyta- green– Rhodophyta-red– Phaeophyta-brown
• Blade: absorbs sunlight • Stipe: carries sugars from the blades to the rest of the plant• Holdfast: anchors the plant to rocks
Types of Seaweeds
Chlorophyta• Mostly freshwater• Simplest• Similar to land plants
Phaeophyta• Almost all marine• Dominant on rocky
coastlines• Can take exposure to air• Largest in size and most
complex• Forests of kelp seaweed
are productive environments
• Gas filled floats
Types of Seaweed• Rhodophyta
– More species than other two groups combined
– More simplified than brown group but variety of shapes and sizes
– Wide tolerance of environmental conditions- shape varies in response
Economic Importance• Food
• Chemicals used in food processing and thickening, emulsifying and stabilizing
• Chemicals added to cosmetics and pharmaceuticals
• Fertilizers
• Possible biofuel
• http://www.google.com/images?hl=en&sugexp=gsihc&pq=prickly+pear+cactus&xhr=t&q=prickly+pear+cactus+nj&cp=20&bav=on.2,or.r_gc.r_pw.&wrapid=tlif130012414002010&um=1&ie=UTF-8&source=og&sa=N&tab=wi&biw=1020&bih=578
Marine Plants
•Mangroves, salt marsh plants and sea grasses
•True leaves, stems and roots
•Specialized tissues•Evolved from land plants
Salt Marsh Grasses
• Inhabit shores and estuaries protected from wave action
• Usually only submerged by high tide• Many have salt glands to excrete
excess salt• Important in stabilizing sand dunes
which buffer and reduce impact of storm waves and wind
Mangroves
• Shrubs and trees adapted to live on muddy or sandy shores
• Can tolerate salt, low oxygen sediment, and submergence
• Grow in thick forests in tropical and subtropical latitudes