BBRAeNEWS No.124 - DEAD FISHES FOUND IN BANDAR BOTANIC LAKES.

Dead fishes found in Bandar Botanic Lakes.

Recently, a few fishes surfaced in Phase 3 and 4 and are found dead. And the cats are there waiting. What are the causes?
When a number of dead fish are found in one place, the incident is referred to as a fish kill, and there is significant reason to suspect pollution. The three main causes of fish kills are poisoning, disease, and suffocation. Dead fish and fish kill are caused by lack of oxygen, disease, pollution, stress, toxic algae, pesticides, starvation, old age and anoxic (no oxygen) water in storm drains that enters lakes, ponds or reservoirs during heavy rain after long drought periods. Lack of oxygen from a few feet below the surface to the bottom may cause fish to only swim in the surface water. If the surface water is warm, dead fish or a fish kill could be from the warm water or from ammonia and carbon dioxide in the bloodstream turning into gas bubbles. In most every case, restoring the water body can prevent dead fish and fish kills.

Poisoning
Fish may be poisoned by a wide range of polluting substances, including pesticides, acids, ammonia, phenols, cresols, compounds of metals, detergents, or cyanides. Many of these are released through drains or are accidentally spilled into waterways. Acid rain, causes rivers to become toxic for various kinds of fish. Some types of toxic algal blooms kill fish.

Disease
The disease may be caused by viral infections, bacteria, fungi, or internal or external parasites. In these same natural environments, it is more common for fish to be weakened by disease and then killed en masse by some stressful environmental situation, such as low-oxygen concentration, temperature extremes, or pollution.

Suffocation
Suffocation occurs when the oxygen concentration in the water falls below the level at which fish can survive. When the excess plant growth decays, it lowers the oxygen concentration. The discharge of dead organic matter into a watercourse from a sewer or from an industrial operation has the same effect.

Nuisance algal blooms may also cause suffocation. The bloom sank and decomposed, forming an area with almost no oxygen and with lethal levels of hydrogen sulfide. Many fish kills could be prevented by reducing the amount of pollution, especially nitrogen and phosphorus, entering waterways.

What is your say residents?