Risk Analysis of Water Quality in Aquaculture. A case study of Ilorin metropolis, Kwara State, Nigeria

Agricultural products were among the primary export commodities together with petroleum products during the pre-independence era which made the Nigerian economy fairly stable then, contributing about 95% of the total Gross Domestic Product (GDP). After independence, there has been a steady and consistent decline in the value of agricultural products such that as at year 2002, it was estimated to be 32% of the nation’s GDP (Gross Domestic Product) which shows that economic growth in Nigeria has been affected greatly by resilient agricultural growth. Nigeria is one of the top 3 aquaculture producers in Africa (6.5%) and this has been as a result of increased demand, consumption and preference for seafood products especially fish and molluscs over red meat all over the country (Dixie &Ohen, 2006). Also, there’s been a growing awareness of aquaculture production in the country which has been made possible through extensive work in fields like marine biology to overcome constraints and also to intensify fish production. This rapid growth in the aquaculture sector however, contrasts with the decline or near stagnation in the growth of supplies from capture fisheries which can be amended if only if there’s a continuous awareness to improve the quality as well as the quantity of aquatic organisms produced locally (FAO, 2005). Aquaculture production is fraught with risks (Erondu &Anyanwu, 2005) as most of the aquatic organisms become potentially endangered as a result of habitat degradation (FAO, 1984;Vitule et al, 2005) due to unpredictable changes in biological processes in the pond environment which causes a malfunction of the ecosystem having serious economic and environmental consequences (FAO, 2010). 

       Risk according to Aquatic Animal Health Code (2012) can be seen as the likelihood that an event, having an adverse effect on animal and human health will occur, together with the magnitude of its occurrence and its biological and economic consequences. The study of risk in aquaculture is usually based on the probability of that event occurring as many times as the consequence of that given event occurred. Risks occur due to changes in physical factors like a) temperature &pH, b) high concentration of toxic pollutants (chemicals like copper and zinc which are present in water treatment e.g. copper, zinc) and c) biological factors like incidence of pests and diseases, high microbial population etc. (Anon) This happens as a result of the constant disturbance in our ecosystem via climatic changes and human interference which exerts more pressure on the limited resources we have. This in turn, increases the rate of risks which are usually associated with natural disasters like flooding, droughts etc. 

      Risk analysis on the other hand, can be seen as a systematic and objective way of assessing the likelihood of negative consequences occurring due to an activity. Having the knowledge of risk analysis in aquaculture production serves as a model to assist fish farmers (McDiarmid, 2001) to identify and manage risks in aquaculture (Wooldridge, 2001) to prevent or lessen the effect of these uncertainties or consequences (Thrusfield, 1995, Fagbenro et al, 2002) on production, regardless of their income level. Risk analysis provides a way to know what can actually go wrong, the mode of its occurrence, the effect/consequences of its occurrence and ways to remedy the effect of this occurrence (risk management) regardless of the method of risk assessment used. In the absence of required information or expertise needed, stakeholders’ qualitative knowledge of the water environment can be used in the assessment (Brun, 2013). Afterwards, the results obtained from the analysis and assessment conducted can then be communicated to the end users who might benefit from it. In this study, risk analysis was carried out using information obtained from structured interview questionnaires.