Nicaragua ’s two biosphere reserves were indirectly based on a model proposed for protecting several vast areas in the southeast United States. The strategy is to create a central “nucleus zone,” with wilderness status totally preventing human activity.
The nucleus is then surrounded by various levels of buffer zones with increasing, but still regulated, resource exploitation permitted as the distance increases from the center.
That’s the intention, anyway. The virgin lands of Bosawás and the Río San Juan  areas have long served as “safety valves” for Nicaragua’s expanding population, accommodating campesinos as they look for new forestland to clear and farm. Several hundred campesino families currently inhabit the Bosawás reserve, and in the absence of regulation, more will surely follow.
Located in the remote north-central wilds of Nicaragua, Bosawás is the largest continuous expanse of virgin cloud forest in Central America. In the extreme southeast of Nicaragua, the Refugio de Vida Silvestre Río San Juan  stretches from El Castillo  southeast to the Atlantic Ocean along the north edge of the Río San Juan.
In addition to the river itself, an important part of the reserve are the four interconnected lagoons at the river’s mouth and their related pools, all of which are crucial habitat for manatees and several other mammals.