AP BIOLOGY

Detailed explanation-1: -So, the correct option is ‘Open Ocean’.

Detailed explanation-2: -Answer and Explanation: The open ocean has the least primary production in aquatic biomes. Open ocean’s surface water is deficient in nutrients as the dead organic matter sink into the ocean.

Detailed explanation-3: -In surface waters away from coastlines, generally there is plenty of sun but not enough nutrients. So most of the ocean surface is not very productive. The water is too deep for storms to stir up nutrients from the bottom and there isn’t upwelling.

Detailed explanation-4: -Open oceans have a lower rate of primary productivity. The cold, nutrient-rich waters of the aphotic zone experience limited mixing with the warm, sunlit surface waters. Most biomass of open oceans are found within 200m of the ocean’s surface.

Detailed explanation-5: -Answer and Explanation: Biological productivity is low in the open ocean because the open ocean has low nutrient levels. Producers need nutrients to grow and multiply. Coastal areas are nourished by surface runoff from the land and they thus have higher levels of biological productivity.