ECOLOGY
ECOSYSTEM
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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The ocean floor contains many decomposers
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Most sunlight is absorbed before reaching these levels
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Water is a limiting factor
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The temperature in these zones is extremely low
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Detailed explanation-1: -Photosynthesis requires sunlight and therefore phytoplankton are restricted to the upper 50-100 m of oceanic water bodies because this is the maximum depth to which sunlight penetrates the water environment. Growth also depends upon mineral nutrients with the greatest supply coming from land.
Detailed explanation-2: -Down in the ocean depths, lots of nutrients are available for the phytoplankton, but without sunlight, they can’t grow. For the phytoplankton to use the nutrients, the nutrients must be transported to the surface. During the summer, the sun warms the surface layer of the ocean.
Detailed explanation-3: -They also require trace amounts of iron which limits phytoplankton growth in large areas of the ocean because iron concentrations are very low. Other factors influence phytoplankton growth rates, including water temperature and salinity, water depth, wind, and what kinds of predators are grazing on them.
Detailed explanation-4: -Because they need light, phytoplankton live near the surface, where enough sunlight can penetrate to power photosynthesis.