In the south of Spain, the Minor Sea has been the scene of a horrible spectacle in recent days. What was a tourist paradise a short time ago has become a dying area due to heavy nitrate pollution. Tons of dead fish have recently been found on the beaches.
The most serious mortality of fauna in the Minor Sea
The Minor Sea is a saltwater lagoon of 17,000 hectares (135 km²) located in the south-east of the region of Murcia (Spain) and separated by a coastal barrier with a length of 21 km. This tourist region recently made headlines in Spain due to a large-scale ecological disaster. Many fish died, dying on the beach and in the water trying to suck in some air.
The massacre began on August 17 and seven days later, local authorities estimated the amount of lifeless fish recovered to be between 4.5 and 5 tonnes. Since then, dead fish have continued to appear regularly, a sign that the disaster is not yet over. According to the World Wide Fund for Nature (WWF), this is the most serious mortality of fauna in the known history of the Minor Sea.
Credits: YouTube / El Mundo capture
Why such a disaster?
Associations are naturally indignant, also pointing to a massive flight of tourists. On public television, a local resident said she had not been able to swim for three years because of the foul odor invading the beach on a regular basis. The reason for this situation is none other than the lack of oxygen in the water, caused by massive releases of nitrates. We are talking here about hundreds of tons of fertilizers used in intensive agriculture.
The point is, nitrates stimulate the growth of algae, phytoplankton that form a green or brown layer on the surface of the water as it proliferates. This layer then prevents light from reaching the bottom, the maximum depth of the Minor Sea being seven meters. As a result, the seabed vegetation dies and the amount of oxygen in the water is reduced, causing the asphyxiation of the aquatic ecosystem of which the fish are a part. This is a phenomenon known as eutrophication which should develop even more due to the current climate change.
In addition, the heat wave of mid-August in the region was one of the components of this massacre. However, other reasons play their role in general, besides nitrate pollution. Indeed, the nautical ports would be too numerous, in addition to the construction of housing estates destroying the coast and large quantities of mineral sediments. In 2019, the Minor Sea had already suffered a similar hecatomb although less significant, because “only” three tonnes of dead fish had been recovered.