The Mystery of the Malaga Embalse

One of the great benefits of Fish and Fly going global is that we can pool advice and experiences from every country in the world. And some of the fly fishermen down on Spain’s south coast need a bit of help, more than most at the moment. We have plenty of friends who fish an exquisite reservoir down there and they are in deep trouble.

This reservoir – or Embalse – is some half an hour north of Malaga on Spain’s famous Costa del Sol. The water is some six miles long and averages a mile across. It’s festooned with bays and long arms that probe into the surrounding countryside. The dam was built some decades ago and the reservoir has played an important role in providing both Malaga and neighbouring Marbella with water. Bass evidently got into the water many years ago and, until recently it was one of Spain’s best waters. Fish were plentiful and many topped the four pound mark – pretty sensational by European standards. Because access to the water is so fiendishly difficult, fishing pressure was kept to a minimum and this, obviously, helped the bass considerably.

So where is the problem? Two things happened during 2004 and 2005 which combined perhaps to produce disaster. Firstly, of course, the building trade down on the Costa del Sol never sleeps. Water demand rises daily and the amount taken out of the Malaga Embalse just continued to rocket during this period. Further, disastrously, the rainfall in this part of Spain also collapsed for long periods of time. The south of Andalucia saw droughts like never before and the Embalse was never nearly full again after May 2004. In fact, by the late summer of 2005, the water had shrunk to perhaps ten percent of its normal volume. In fact, the bed for at least two thirds of the way down the Embalse was dry and completely exposed, as were the coves and arms. As a result, all fish stocks were congregated in the last, albeit large, puddle, close to the dam.

Our friends down there kept a close watched on the water but fished less and less as the water receded. Never once did they see dead bass or, come to that, dead carp or barbel, the two other main species in the lake. Rain in the winter of 2005 – 2006 began to fill the Embalse once again and loud sighs of relief could be heard all round.

However, throughout the summer and autumn of 2006, fishing has been dire. The water is back, the carp and barbel populations are buoyant but the bass catches have been depressed in the extreme. On a water where twenty fish in a day was once the norm, one or two fish is now a good return. Where you could once fish poppers and have bass inspect all day long, it’s now rare to see a single, mature fish inspect a surface lure in a week. Evidently, some mature bass have survived. The odd three and four- pounder is still taken and there are fractionally more fish caught in the one to two pound category. There are also huge numbers of bass fry in the margins – more than anybody can ever remember seeing before. This, too, is surely a good sign.

The big questions are these. Whilst the carp and barbel were able to survive the low water conditions, did something happen to kill off a larger percentage of the bass population? Perhaps chemicals or minerals in the water? Did the shallow water become too warm? Did oxygen levels just fall too low? Do dead bass float so that the tragedy could be recorded? Or do they sink so that no-one guessed the truth?

Or – and this could be clutching at straws – is there another explanation? Could it just be that when the rains came and the Embalse filled again, the ground that had lain exposed for so long became a huge, natural larder? During those long months had so many insects and small creatures colonised the very fertile Embalse bed that, once the water returned, the bass found fantastic feeding, forty, sixty, even eighty feet beneath the surface? Could it just be that the lower zones of the Embalse have been so enriched, that the bass have had no need whatsoever to come to the surface or even to mid-water in order to feed? Have the bass, then, simply adapted to a new and prolific food source? When this is depleted, is it possible that once again, fishing on the Embalse will return to its turn of the century levels?