WATER QUALITY INDICATOR FOR AQUACULTURE IN INTENSIVE CULTURE USING A FUZZY ANALYTICAL HIERARCHY PROCESS

Aquaculture is an activity that can enhance the development of fishing communities and even protect endangered species  due to the high levels of pollution seen in its ecosystem and severe overfishing. A fuzzy analytical hierarchy model for assessing water condition (subsequently FAHP-WQI) from whitefish in intensive culture ponds was developed. FAHP-WQI combines analytic hierarchy process and fuzzy logic.

Temperature, pH, dissolved oxygen and ammonia were considered. Based on the measurements of them, FAHP-WQI obtained an indicator of regarding the water quality condition as a good or bad. It was tested and evaluated in intensive ponds. Additionally, individual weights are computed and allocated according to the parameter importance on the water evaluation.

This was compared with similar models and the proposed index shows a good performance in real environments. Due to index proposed by National Sanitation Foundation (NSF) provides a good basis for the freshwater quality assessment because a weight is assigned to each parameter according to their importance. In Fig.1 is possible to appreciate that NSF shows greater quality, the origin of this difference is in the importance assigned to dissolved oxygen, where practically the result depends primarily on this parameter.

Then, FAHP-WQI was compared with Canadian Council of Ministers of Environment Water-Quality Index ( CCME), which is not composed of a weight system. CCME is calculated using different equations, which they take into account the scope, frequency and breadth. As reflected in Fig.2, CCME shows quality in maximums values, this is because it is an average of all the parameters involved is done, which is why can compensate bad conditions of one parameter with the good ones of another.

This model emerges as an alternative, suitable and reliable tool for the aquaculture of any aquatic species, only ranges must be set up for each species