Answer: They tend to support large planktonic
communities because (of higher dissolved oxygen and nutrient concentrations).
Step-by-step explanation:
Planktonic communities are made up of basic organisms that forms the oceanic food web. They are broadly divided into Phytoplankton (these are the producers), Zooplankton (these are the consumers) and Bacterioplankton (these are the recyclers).
High-latitude ocean water is mostly affected by the quantity of oxygen and nutrients it contains. Large planktonic communities thrives in these aquatic environment because is contains higher amount of dissolved oxygen and nutrient concentrations which forms part of their basic needs for survival. This is so because changes in ocean water can impact all levels of the food web. Increase or decrease in ocean temperature can modify the plankton diversity and distribution directly by altering it's metabolic rates and growth.
Therefore due to the geographic location of high latitude ocean, higher dissolved oxygen and nutrient concentrations favour the survival of a larger planktonic communities than other ocean parts.