also sea temperatures and sea levels are rising and ocean currents shifting resulting in biodiversity and habitat loss changes in fish stock composition and migration patterns and higher frequency of severe ocean weather events the prospects for future ocean development are further aggravated by landbased pollution in particular agricultural runoff chemicals and macro and microplastic pollutants that feed into the ocean from rivers as well as by overfishing and depleted fish stocks in many parts of the world the projections suggest that between and on a businessasusual scenario basis the ocean economy could more than double its contribution to global value added reaching over usd trillion