https www youtube comwatch vp 0 G 68
https: //www. youtube. com/watch? v=p 0 G 68 ORc 8 u. Q Deep Ocean �Not much light penetrates deeper than 200 m = 600 ft �Photosynthesis not possible �Producers (autotrophs = self feeders) here must find substances by other means �Life without sunlight: https: //www. youtube. com/ watch? v=-3 m. PEPj. Ony. I
Chemosynthesis �captures the chemical energy of dissolved minerals �chemosynthetic bacteria at hydrothermal vents make energy available to the food chain in the deep sea �Only some species of bacteria derive energy from the oxidation of inorganic substances (like hydrogen sulphide), and use this energy to synthesize organic compounds
Hydrothermal Vents �Fluid emerging from hydrothermal vents is rich in hydrogen sulphide and other gases. � Chemosynthetic bacteria oxidize H 2 S and fix CO 2 to form organic substances � Provide food source for animals in the hydrothermal vent ecosystem � Example: � tube worm � giant clams
Riftia �Symbiotic relationship with chemosynthetic bacteria �Provide nutrients TO Riftia �Extremophile: An organism that is adapted to survive EXTREMES �Temperature �Pressure �Salinity �p. H
Comparison: Chemo vs Photo
Self-Assessment �Draw out and complete the following table to compare photosynthesis and chemosynthesis in ocean ecosystems. Feature Energy source Products Type of organism Main location in ocean Chemosynthesis Photosynthesis
Practice Assessment 1. Compare the ways in which vent bacteria and phytoplankton make energy available to these food chains. [3] 2. List three reasons why phytoplankton cannot survive at a hydrothermal vent. [3]
Productivity �The rate of accumulation/production of biomass/energy �Biomass = the mass of living biological organisms in an ecosystem at a given time �Measured in terms of energy capture per unit area (or per unit volume in aquatic ecosystems) per year
Productivity �Almost all ecosystems = green plants are primary producers �Refer to primary production in relation to plants �Consumers depend directly or indirectly on the energy captured by primary producers �Productivity of an ecosystem affects all trophic levels
Productivity �When conditions are favorable for photosynthesis, the productivity of the ecosystem tends to be relatively high �Example: �tropical rain forests �algal beds and reefs The Biological Productivity of the Ocean https: //www. nature. com/scitable/knowledge/library/the-biological-productivityof-the-ocean-70631104
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