No.
Scientists now estimate that 80% of species on Earth live on land, while only 15% live in the ocean, and the remaining 5% live in freshwater. They do not think that the difference is entirely due to better development of the territory. Gilat, a marine ecologist and biologist who studies the differences between terrestrial and marine life. Vermoki thinks the oceans' lack of diversity isn't just about our preference for land-based creatures. As ocean researchers, Vermoki and others are keenly aware of this bias. So how is the capacity of land to support biodiversity fundamentally different from that of oceans? One reason given by May and others is that the physical configuration of terrestrial habitats may be more fragmented and diverse.
Plants certainly play a major role.
The turning point of the Earth, passing from'a domination of marine life to a domination of land life, occurred about 125 million years ago, during the Cretaceous period, when early-flowering plants evolved very successfully on earth. Plants need sunlight for photosynthesis, but it is rarely available in the ocean outside of shallow coastal areas. For this reason, productivity is significantly higher on land than in the cold, dark depths of the ocean.