Beach go-ers along the ECR this past weekend were shocked to see many dead fish along the shoreline. There were a variety of fish, ranging from eels to the local nethili and a few keluthi (cat fish) as well. The stretch of dead fish covered a distance of a few kilometers right from Injambakkam to Panaiyur and many fish were washed up ashore along the several beaches that can be accessed along the many roads that lead to usually pristine beaches. Over the past few months, drying lakes have caused large numbers of dead fish in other parts of the city and coast as well.
What could cause this on ECR beaches and what can we as responsible beach go-ers do; when we encounter such a situation? The first likely suspect in such an incident is a fishing boat accident. If a fishing boat carrying its catch were to have an accident and many of the fish caught fell overboard, they will all eventually wash up to the shores. In these cases, there is not much to worry about — it is just that it is an inconvenience on the beaches as there is a foul smell of putrid fish as they decompose on the shoreline.
They will eventually biodegrade and become part of the beach sand. Changes in tides may also wash them back into the ocean. I also spotted many sea birds and crows which can carry these dead fish into the city and drop them in homes many kilometers from the beach! So if there is a suspicious fish in your yard or garden this is probably the cause for it. The other possible reason for such a large number of dead fish along the beaches could be if there is a contamination in the ocean. Effluents from shoreside industries, untreated sewage or even chemical spills from smaller boats could be the cause. It is possible that the fish are contaminated with toxins and it is best to avoid touching them or consuming them. Due to lacking awareness, some fishermen turn these into dried fish and resell them, which could prove dangerous. Keep your pets away as well — they may be tempted to pick up the fish in their mouths if they encounter them while on a leisurely stroll on the beach.
The final and most deadly possible cause for this is what is known as ‘fish kill’ or ‘fish die off ’ This refers to a localized dying of a large fish population most commonly caused by reduced oxygen levels. A reduction in oxygen in water could be due to algae overpopulation or even a sustained increase in water temperature. Fish kills are often the first visible signs of environmental stress and require to be urgently investigated by environmental agencies to determine the root cause. Many fish species have a relatively low tolerance of variations in environmental conditions and their death is often a potent indicator of problems in their environment.
These same stresses could affect other animals and plants and may have a direct impact on the quality of desalinated water. In these cases, it is best to launch a complaint to the local authorities when you encounter fish kill on a local beach. Don’t turn a blind eye the next time you experience something unusual on your beaches as we are all connected on this planet and each step we take matters.