oligotrophic

Poor in minerals and bases. The term is usually used of ponds and lakes with low nutrient levels but it can be applied in other contexts, for example to bog peats, which are usually low in nutrients. In an oligotrophic stretch of freshwater there is limited growth of aquatic plants. There is consequently little decaying vegetable matter and the absence of large numbers of decomposers means there is sufficient oxygen to support fish and other aquatic animals. Compare eutrophic.