Aquaculture is a particularly high-risk type of farming. The aquaculturist is rarely certain as to the exact number of animals that are in the culture system. Since aquatic organisms live underwater, they are often difficult to observe and never easy to count. Mortalities may occur that are never discovered. Dead animals may be consumed by other animal in system or they may decay without floating to the surface where they can be observed and for disposal. Excessive amounts of feed may be provided when the number and biomass of organisms in the system are overestimated. As a result, water quality problems may arise. In any event feed equates to money wasted.