What are three reasons why plants are more abundant in cold seas then warm seas?

Plants are more abundant in cold seas primarily due to higher nutrient availability; cold waters often feature upwelling currents that bring nutrient-rich sediments to the surface. Additionally, colder temperatures can support a wider variety of phytoplankton, which form the base of the marine food web. Finally, cold seas typically experience less stratification, allowing for better mixing of water layers and promoting a more favorable environment for plant growth.