Laguna de Apoyo

Volcanic crater, 23000 yo. Biologicaly very young, also isolated from its neighbour larger lakes. Water temperature 28-29 ºC (some warm water springs at the lake), maximum depth abt 250 m. Only few species of fishes (5-9), and some of them affected by illnesses introduced by imported animals. Sandy bottom, largely covered by a thin layer of algae (?) over darker (organic?) matter. Arsenium contents seem to be high. Quite simple and uniform area - though interesting.