Statement I : Phytoplankton produce most of the organic carbon in the ocean Statement I : Algae are produced in the cold water biome

Statement I is true as phytoplankton are the primary producers in the marine ecosystem, responsible for nearly 99% of marine vegetation and the vast majority of primary productivity [2]. They convert inorganic nutrients and carbon dioxide into organic carbon through photosynthesis, forming the base of the marine food web [3]. Statement II is also true; algae (including phytoplankton and seaweeds) are produced in cold water biomes, such as the Polar Regions and cold water masses like the Yellow Sea Cold Water Mass [6]. While phytoplankton are present in all lighted regions of the oceans, cold waters often support significant blooms due to nutrient availability [6]. However, Statement II is not the correct explanation for Statement I because the high organic carbon production by phytoplankton is a result of their global distribution and photosynthetic efficiency across all temperature ranges, not specifically because they are produced in cold water biomes [5].

Sources

1. [2] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 3: MAJOR BIOMES > Plant Life in a marine ecosystem > p. 29
2. [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 30: Climatic Regions > Geographical advantage > p. 465
3. [3] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 14: Marine Organisms > The Carbon Cycle and climate change > p. 208
4. [5] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 14: Marine Organisms > 14.2 PHYTOPLANKTON > p. 207
5. [6] https://www.nature.com/scitable/knowledge/library/the-biological-productivity-of-the-ocean-70631104/
6. [4] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 3: MAJOR BIOMES > Food Chains in Marine Biomes > p. 33