(1) The main thrust of global conservation efforts today is to protect not just individual species but entire ecosystems. The goal is to preserve the natural interactions of many species. To that end, governments and conservation groups work to set aside land as parks and reserves. The United States has national parks, forests, and other protected areas. Marine sanctuaries are being created to protect coral reefs and marine mammals. (2) The challenge is protecting areas that are large enough and that contain the right resources to protect biodiversity. To make sure that conservation efforts are concentrated in the most important places. conservation biologists have identified ecological hotspots'. An ecological hotspot is a place where significant numbers of species and habitats are in immediate danger of extinction. By identifying these areas, ecologists hope that scientists and governments can better target their efforts to save as many species as possible.
The word extinction in Paragraph (2) is closest in meaning to