The drop in salinity levels in the Mar Menor is encouraging the entry into the lagoon of fauna that lives in the Mediterranean, which could endanger the survival of species such as the nacre, the seahorse or the marlin. The experts are confident that the situation is temporary, that the high summer temperatures will increase evaporation and that this will serve to rebalance the salt concentration, returning it to the usual levels of around 45 grams of salt per litre.
The high level of salinity of the waters of the Mar Menor is one of the factors that make this area a unique ecosystem, with a clearly differentiated population of fauna and flora. It has sheltered species that in the Mediterranean would be highly threatened by natural predators, and it is also home to molluscs such as the nacre, which the salinity protects because it deactivates the parasite that kills it. For this reason, experts are extremely concerned that the decrease in salt concentration will open the door to the Mar Menor to species such as the loggerhead turtle, which may feed on nacra. Emilio Cortés, who is curator of the aquarium at the University of Murcia, says the situation is especially serious in the case of these molluscs because in recent months they have been showing serious problems in reproducing successfully.
Turtles are not the only species alien to the Mar Menor that has been observed in the lagoon in recent months. Divers have been able to identify octopuses and groupers, predators that have not been recorded in the lagoon’s recent history and which represent a serious threat to seahorses, marlin and foxes.
The experts hope that this drop in salinity is temporary and does not last too long, as this would allow the lagoon’s own fauna to increase their populations naturally again.