A combination of factors causes the death of thousands of fish in the Mar Menor

Scientific experts in the field point to a series of circumstances that provoked this environmental disaster and suggest possible solutions.

CARTAGENA, Spain, Aug. 31, 2021 /PRNewswire/ -- Thousands of dead fish have been washing up on the shores of the Mar Menor for days. Something similar already happened in 2019, and although solutions are on the table, corresponding authorities have not yet taken the necessary measures. On top of this is the problem of a lack of information, or rather, the misinformation with which the problem is addressed from many fronts, which leads some environmental groups to point to modern agriculture as the main culprit, an accusation denied by leading experts in the field.

The first indications seem to show that there is an evident correlation between the death of these fish and extreme temperatures that took place in the recent heat wave (during which, the ambient temperature reached 40 °C and more than 30 °C in water). This was in addition to a massive arrival of tourists, with more than 200,000 in the areas surrounding the Mar Menor (where many houses and urbanizations still pour their waters into the sea), in some coastal towns that do not dispose of the necessary infrastructure to purify and channel water and urban waste. These circumstances have come to enhance a problem that has been damaging the area for a long time, and which it is urgent to take effective measures against.

In addition, there are several other factors that affect the pollution of the Mar Menor. The marinas and artificial beaches, the narrowing of the gullies, the lack of infrastructure to stop the increasingly frequent torrential storms, the slurry from livestock and the toxic remains from mining in nearby mountains are some activities that undoubtedly affect the lagoon.

But there is more. Currently entering the Mar Menor through the groundwater (called Quaternary aquifer) is a high concentration of fresh water mixed with nutrients, due to historical accumulation and derived from agricultural practices dating back three decades and permeating into the subsoil. These practices are by and large not comparable with those developed by modern agriculture, which uses localized irrigation techniques (fertigation), and which some erroneously blame as responsible without understanding the true origin.

Indeed, some experts maintain that agriculture could actually be a substantial part of the solution by extracting and using groundwater for irrigation, which would contribute to generating a sustainable model and solving the aquifer problem.

Framed in this context is the need to execute on the infrastructure provided for in the Zero Dumping Plan, which has so far not been triggered, and to implement the Environmental Protection Ring (Spanish acronym APA), a comprehensive solution designed by Fundación Ingenio, an entity that unites more than 10,000 farmers and 45 cooperatives from Campo de Cartagena. Prepared by academics of national and international prestige, the Environmental Protection Ring presents a "real, definitive, comprehensive and short-term solution to the problems of spills into the Mar Menor, as well as those produced by the overload of the sanitation network during the summer season," according to Natalia Corbalán, Director, Fundación Ingenio.

Fundación Ingenio has been studying the causes of the serious environmental problems seen in the Mar Menor for some time, and they have observed urban discharges, underground water discharges, sewage and pipe breaks leading to the Mar Menor and its surrounding beaches. For this reason, as Corbalán explains, "The APA includes a series of measures that would prevent the entry of water from heavy rains and torrential storms, which are increasingly frequent, and from all the other factors previously mentioned." She also envisions efforts to extract underground water that is polluted by urban discharges, nutrients, slurry and other sources of contamination which originate from different outside the quaternary aquifer, and which produce harmful discharge by the minute, and flow into the Mar Menor without any type of control.