ARCHIVED - VIDEO: Lack of oxygen kills thousands of fish and shellfish in the Mar Menor

Lack of oxygen in the water is believed to be the cause of the incident

The red flag for no bathing has been hoisted on the beach of Villananitos in Los Pagán, san Pedro del Pinatar, following the appearance of thousands of dead and dying fish and crustaceans, gasping for air and dying on the shores of the beach on Saturday morning.

Passers by videoed what was happening, posting it on social media, and before long Protección Civíl and environmental officers from the Ministry of Agriculture had arrived at the scene, joining the crowd of shocked onlookers who could do nothing but watch the fish die.

During the week Antonio Luengo, the minister for the environment in the Murcia government, confirmed that the water quality in the lagoon is currently much worse than before the gota fría, and that unfortunately “the patient is back in intensive care”.

Water quality results released this week showed that on the one hand the amount of chlorophyll in the water has dropped back to around 3 or 4 micrograms per litre, having shot up to over 30 immediately after the heavy rain, but on the other hand the oxygen level in the water is still worryingly low.

Following the first meeting of the Inter-administration Mar Menor Co-ordination Forum which has been set up in order to oversee a co-ordinated effort by all bodies involved in the administration of the Mar Menor to resolve the problems exacerbated by the recent Gota Fría, Sr Luengo commented that the consequences of this shortage of oxygen for marine flora and fauna have not yet been evaluated, but the appearance of so many dead fish this morning are symptomatic of a lack of oxygen in the water.

What appears to have happened is that the massive volumes of water and debris which washed into the Mar Menor during the Gota Fría, increasing the water level in the 170 square kilometre lagoon by nearly half a metre, have brought non-salinated water into the salinated and concentrated waters contained within the largest body of non-tidal saltwater in Europe.

The clean-up teams have removed 4,200 cubic metres of debris including 25 rubbish containers, several cars, trees and furniture from the water since the storms, and although the sweet water is slowly mixing with the saltwater, two layers of water have been temporarily formed, with the oxygenated saltwater sinking to the bottom and the non-saline water sitting in a pocket on the top.

The lack of oxygen has been exacerbated by the proliferation of algae in the water following the storm, although the algal bloom experienced three years ago has been held at bay by the turbidity of the water due to the high volume of silt washed into the water by the storms which is keeping visibility low and preventing the sunlight from piercing into the depths of the water,  and fuelling an algal bloom.

On Thursday the wind direction changed and pushed the non-saline water towards the northern end of the Mar Menor, the marine life in this area moving towards the surface of the water in search of oxygenated water as the layer of non-saline water moved towards the shore, thousands of them washing up on the beaches as they moved to the surface in search of oxygen.

A member of our own team was windsurfing in these same winds on the Mar Menor during Friday evening and observed several larger fish floating on the surface of the water near to this point, and on Saturday morning, as the videos clearly show, thousands of fish of all sizes ended up on the beach, gasping for oxygen.

Miriam Pérez Albaladejo, Director General of the Mar Menor was amongst those who attended the incident on the beach this morning.

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