What can you conclude about the importance of marine ecosystems to global food webs and the biosphere?

It is more precise to illustrate biosphere as the global ecosystem in spite of the global community as it just comprises all the living things in a specific region considering their distinct species. Although, when one says ecosystem, one automatically comprise both nonliving and living things like water, soil, and others. Thus, it is more correct in terming global ecosystem when one is considering biosphere of the Earth.  

Explanation:

As marine ecosystems include about 70 percent of the surface of the Earth, the influence of these ecosystems on the global food web is advanced. The oceans are an essential source of oxygen for the planet and are efficient in the retrieval and space for carbon dioxide. The marine classes offer essential ecosystem services like the generation of drugs, food, and livelihoods. They also encourage tourism and frivolous projects around the globe.  

the ozone layer acts as a filter for the shorter wavelength and highly hazardous ultraviolet radiation (uvr) from the sun, protecting life on earth from its potentially harmful effects. when the sky is clear, there is an inverse relationship between stratospheric ozone and solar uvr measured at the earth's surface.