A Professor of Fish Nutrition, Fisheries and Ecotoxicology has warned the masses against consuming fish grown in sick water to avoid taking ill. Professor Lawrence Nwanna of the Department of Fisheries and Aquaculture Technology at the Federal University of Technology, Akure gave the warning while delivering the 127th Inaugural Lecture held in the new auditorium of the University on Tuesday, 18th May, 2021.
Nwanna, who spoke on the topic: “Nutritional Concepts and Fisheries Production” in Sick Waters said fish perform all physiological activities in water, including breathing, excretion of waste, feeding, maintenance of salt balance and reproduction. Therefore, producing fish in sick water is tantamount to sentencing the fish to death, which if consumed by human can make them sick. He added that most of his research efforts are tailored towards ensuring that fisheries are not produced in sick waters, because eating fish produced in sick waters bad for the health of consumers of fish. Nwanna also condemned the practice of washing clothes with detergent in running waters and streams and rivers. He said “people still wash their clothes with detergents in our water ways and rivers thereby causing ecosystem tragedy. “Poisoned water is sick water and the sickness can be transferred to people after consuming the poisoned fish or using the water for other domestic purposes” Nwanna said.
Professor Nwanna listed causes of sick waters and consequences on fisheries production to include presence of heavy metals, feed additives, pesticides, dyes, phytoplankton toxins, oils, surfactants, and hydrocarbons in the water. He added that oils and oil refined products impact the water and make it sick because they coat the surface of the water, not allowing oxygen dissolution therefore organisms die of suffocation, particularly in the areas of high temperature.
Explaining the effect of phytoplankton toxins, the don said “phosphorous is needed for good aquatic production, but in excess, it causes eutrophication of the water body and algal bloom. This bloom makes the water sick by raising the pH to sick and unacceptable level and the collapse of the bloom and consequent decomposition together with other decaying organic matters can cause dissolved oxygen deficit leading to suffocation and death” of fish and other aquatic creatures .
Nwanna said based on the above stated factors that contaminates water, many fish farmers and fishers have abandoned their fisheries businesses because they are producing/harvesting fish in sick waters, with unrewarding catch per unit effort and low returns on investment.
Nwanna, a well-travelled researcher across the globe and multiple award winner said Nigeria has no business with importation of fish and fish products because all the water and human resources are sufficient to produce enough fish for the citizenry and exportation, but for lack of stringent and deterrent policies and unsuitable environment.
He recommended enforcement of strict regulation on the pollution and use of obnoxious fishing methods in Nigerian waters, saying offenders must be punished accordingly. He called on government to make funds available for the studies on culturable wild indigenous fish species to complement the cultivation of African catfish. This according to him can be done through genetic improvement of the indigenous fish species to boost production as most of the exotic fish species do not thrive very well to support the aquaculture production.
Proffering solution to high costs of fish feeds, the Don urged government to establish hatcheries and fish feed mills that will be able to produce and supply the fish seed and feeds needed for aquaculture.
On the application of research findings on fish production, Nwanna recommended thus, “There must be viable and effective fisheries extension and communication programmmes that will ensure that all the research findings from the institutions across the country are harnessed and disseminated to the end users who are the fish farmers”. He also said “fisheries is a professional course and should be chattered with a national directorate and director who should be saddled with the responsibility for coordinating fisheries and aquaculture production programmes in Nigeria”. In the area of job creation, Nwanna called on government to reactivate all the River Basin Development Authorities for job creation and to boost fisheries production.
In his address, the Chairman at the event and Vice Chancellor, Professor Joseph Fuwape, described Professor Nwanna as a thoroughbred academic who has added value to his area of study locally and internationally. He said “the world is facing a global water quality crisis with increasing unregulated discharge of pollutants into our water bodies. This presents a serious threat to human health and wellbeing as well as fisheries production globally. No doubt, Professor Nwanna, a fellow of many international organizations and recipient of many grants and awards has done justice to the topic.”