During which season is productivity the greatest in temperate waters?

Spring season

Explanation:

Productivity in the ocean water varies with the varying seasons, both globally and locally. The marine productivity is measured by the amount of chlorophyll and nutrients present in the water. Spring is the season of blossoms. Tress and flower plants begins to flourish during spring seasons. And plants are source of energy to nearly every living organisms on earth. Plant has the unique ability to directly convert the sun light to energy and also to organic matter which can be used as the source of food for the organisms living in the water body. Also plants produces oxygen which is the source of living for all the marine animals found in the waters. Therefore the animals live and breed during these seasons thus increasing the productivity.

The answer is Spring