Harvestable fish, an important source of protein for humans, and aquatic biodiversity, are also threatened. Catch per unit effort, which grew during most of this century, has been declining for the past 1-2 decades. It has only recently been recognized how seriously marine biodiversity is at risk. It was thought that the vastness of the oceans might not prevent over-fishing, but at least would prevent outright extinction. Now we are less sure.
Coastal ecosystems are one of the richest locations of marine biodiversity.
Economic uses of marine resources include fish for human consumption, animal feed, fertilizer, clothing, jewelry, additives in foods, cosmetics and household products 4. Land Transformation of the landscape is one of the most obvious manifestation of global environmental change. As we shall see, transformation of the land, largely into intensely cultivated agriculture but also into marginal lands, waste lands, and urban areas, can be viewed as a major driver of other global environmental changes, including loss of species and degradation of ecosystems. Population growth and need for greater food production are obvious drivers of landscape change. Agricultural Productivity Population growth means that more food is needed simply to maintain the current food supply per person.