I was in Lal Bagh last weekend with an old friend, reliving our ancient tradition of going for a walk in the morning and then frequenting one of Basavanagudi's fine breakfast establishments. 

We walked around the Lal Bagh lake - perhaps one of Bangalore's healthiest lakes, with a thriving ecosystem that includes several species of fish; a sizeable population of birds such as cormorants, herons and even a couple of pelicans. This doesn't include, of course, the large number of black kites and parakeets that frequent every part of the botanical garden. 

On the western edge of the Lal Bagh lake is a lotus pond - one of many Tavarekeres that used to be ubiquitous in Bangalore and its surrounds. It was here that I came across a most curious spectacle: a lot of fish swimming close to the surface, mouths open. 

It was fairly obvious that what we were seeing was not normal behaviour - every patch of clear water in the lotus pond was teeming with fish, doing their best to gulp down some air. The pond surface was a constant shimmer, with sunlight glinting off the feverishly working fish. 

I am not aware of precedent here, but the lotus pond seemed to be teeming with too much vegetation, with lotus plants and hydrangea covering far too much of the pond, leaving precious little breathing space for the fish. 

October is a time when Bangalore has already received much of its summer and monsoon rainfall, a time when lakes should be full and teeming with life. Just not quite this way. 

I'm far from an expert on this, but one can piece together what has likely happened here without too much difficulty. Along with what little rain that drained into the pond from its surrounds, a good amount of sewage (and perhaps fertilizers used in Lal Bagh?) would have entered in. Plant growth would have accelerated thanks to the availability of fresh nutrients, some of which might have also promoted the excessive spawning of fish in the pond. This seems to have inevitably led to very low oxygen availability in the pond, resulting in the slow asphyxiation of its aquatic inhabitants. The dissolved oxygen available fails miserably in keeping up with the biological oxygen demand. 

Bangalore has had a dismal record of taking care of its lakes, with thousands of fish dying in other lakes in the past, either due to contamination with toxic substances, or due to very low oxyen levels. Public officials who claim that this is a problem of the past are lying through their teeth. As recent as a month ago, around 40,000 thousand fish were feared dead in a pond in Ramamurthy Nagar in the city. While it might be true that some action has been taken regarding the safe-guarding of our lake habitats (I for one am glad that the Bangalore Lake Development Authority at least lists all the lakes in Greater Bangalore,) I'm afraid that it is woefully insufficient. 

Bangalore now has several Sewage Treatment Plants in the city, designed to treat waste water before it is allowed into lakes, but there are serious concerns about how many of these are currently operational and at what capacity. Lal Bagh has a sewage treatment plant within their premises, you can see it just below the lake. Its functioning is probably responsible for keeping the main lake reasonably clean and thriving, so I do not wish to cast undue aspersions on the officials running the show there.

However, it would be deeply regrettable if we allow another mass-death of fish in Bangalore, especially in what is the heart of conservation in the city. Surely there must be some remedial measures that can be taken to prevent this from happening. 

I feel guilty for having taken nine days to write this up - I hope that it isn't already too late.