Bangladesh is an agro-based economy, and the freshwater aquaculture plays a significant role in reducing protein deficit and malnutrition while also providing jobs and foreign exchange gains. Freshwater aquaculture contributes significantly to the economic well-being of Bangladeshi fish farmers. Rural freshwater aquaculture accounts for the vast bulk of Bangladesh’s aquaculture production.
However, disease has become a limiting concern in Bangladeshi fish output as aquaculture technologies have expanded and diversified. And disease have become one of the most challenging factor in rural aquaculture.
In Bangladesh, the most common fish diseases include epizootic ulcerative syndrome (EUS), as well as several fungal and parasite disorders. Furthermore, tail and fin rot disease has been detected in several fish farms, and the prevalence of this disease is expected to grow in recent years.
Water quality management is critical in aquaculture for disease prevention. However, the knowledge that the rural farmers possess to maintain their pond water quality is not adequate.
There is a wide range of issues with water quality in aquaculture systems. Maintaining the ideal culture conditions needed for fish health requires a precise balance of nutrients and other elements. Nonetheless, a majority of farmers fail to verify the water quality standards and never provide a rationale for whether their pond is appropriate for fish or shrimp farming.
Farmers employed various strategies, including the use of pesticides, lime, or antibiotics, in response to the diseases. Some farmers add salt to their ponds or modify the water. A few ceased to fertilize and feed the fish in ponds.
All of these steps are precautionary steps. Remarkably, a research reveals that most fish producers, when afflicted with diseases, prioritize using pesticides and antibiotics over alternative preventive methods.
Antibiotics and insecticides are widely utilized and have a proven value in boosting fish output and averting illness outbreaks. The primary uses of aqua-chemicals are in the treatment and prevention of bacterial, fungal, and parasite diseases. They also serve as growth boosters and enhance the productivity of fish culture ponds by improving the water quality.
However, it is the haphazard use that makes Antibiotic use in aquaculture questionable.
According to the research that involved in-person interviews with fish farmers in Bangladesh’s Rajshahi area, the farmers utilized nine active antibiotic components when raising finfish. Nonetheless, the majority of fish farmers (88%) lacked adequate understanding of antibiotics and aqua-chemicals, and 81% were not aware of the appropriate chemical dosages for fish farming.
In the research locations, a large number of fish producers reported using chemicals carelessly. Regarding the long-term impacts of aqua-chemicals on human health and the environment, 72% of fish farmers were unaware of them.
Aqua-chemicals can enter the human body through the food chain and are well acknowledged to have the potential to cause serious health problems, such as neurological, pulmonary, gastrointestinal, and reproductive issues.
Fish illnesses are less frequent at hatcheries where fish are raised in intensive or semi-intensive methods. The aquaria appropriately maintain the quality of their water and take precautions against fish illnesses.
Hormones, however, are another substance used in hatcheries that might endanger the security of food.
There are more than a thousand hatcheries spread out over the nation. Roughly 98% of the fish fries in the whole country come from these fish hatcheries.
These hatcheries have been producing more fish seed by using induced breeding techniques. Induced breeding refers to the technique of stimulating fish for reproduction by injecting hormones into their bodies.
Hormones are also employed in sex reversal and artificial reproduction. In order to increase growth rate or weight gain, the hormone utilized in fish farming for sex reversal attempts to produce monosex populations.
Research has shown that, Hormones can have negative effects similar to those of pesticides and antibiotics, including possible threats to human and environmental health due to hormone-dependent parameters.
Apart from aquaculture, industrial effluents pose a threat to wild fisheries resources. Bangladesh receives a significant volume of untreated industrial waste and wastewater every day into around 200 rivers.
The ground and surface water were poisoned by dangerously high amounts of lead, cadmium, arsenic, and chromium due to the direct dumping of tannery wastes. The typical fish and shellfish species that are consumed locally are also able to accumulate these contaminants due to river pollution.
Numerous human problems, including cancer, renal damage, developmental delay or deformity, unpredictable behavior, etc., have been associated with these sounds.
Therefore, the question arises whether it is safe to eat fish and other seafood produced in Bangladesh.
As the research evidence suggests long term impact, Government must ensure the appropriate use of hormones and antibiotics in fish farms. Furthermore, operational effluent treatment plant must be set up in every industry so that release of toxic materials can be controlled. Additionally, rural farmers need to be well informed on the right usage of chemicals.
Jaber Bin Abdul Bari
Department of Oceanography, NSTU
