ARCHIVED - Regional government wants to dredge water channel between Mar Menor and the Mediterranean

The regional government has put out a video showing the “pocket of anoxia” which it says has caused the death of five tons of fishes in the last week

On Friday evening the regional government of Murcia announced its intention to dredge the Gola de Marchamalo”, a channel which runs between the Mar Menor, cutting through La Manga del Mar Menor and linking to the Mediterranean.

La bolsa de agua sin oxígeno que está provocando la muerte de peces en el Mar Menor está intentando salir al Mediterráneo a través de la gola de Marchamalo. Es urgente recuperar el calado y facilitar de forma puntual el intercambio de agua. pic.twitter.com/guQ6K5LRyH

— Paco Abril (@PacoAbrilR) August 23, 2021

This channel becomes silted up and has been dredged on previous occasions to deepen the channel between the two bodies of water and was first constructed in 1878 in order to install encañizadas fishing installations ( a system of catching fish first used in this area a thousand years ago in which fish are driven into an enclosure via a caracol of canes and nets).

At the time the decision to break through the 20 kilometre long strip of sandy land dividing the two water bodies prompted a significant reduction in salinity levels which the Mar Menor has never recovered, although it has always maintained a higher level of salinity until recently, but since then other channels including the Gola del Estacio, which permits shipping to transit have been cut, permitting water from the Mediterranean to flow into the Mar Menor and vice versa.

The Marchamalo Gola has a tendency to silt up, and since the first episode of eutrophication in 2016, scientists have argued about whether opening the Gola to increase an interchange of water would do more harm than good, although all are in agreement that it would change the balance of the eco-system in the Mar Menor, altering the salinity of the lagoon and permitting the entry of not only invasive species, such as the blue Atlantic Crab which entered last year, but also of organisms which could adversely affect the population of the Nacra, the giant fan mussel which exist within the Mar Menor.

The regional government claims this video shows the “ball” of water containing the Hydrogen sulphide which is killing the fish being drawn towards the Gola, but finding it difficult to exit due to the shallow conditions within the channel, and is adamant that dredging the gola will permit the toxic gases to leave the Mar Menor.

Threads of the gases can be clearly seen in other areas of the water body, and it is also noteworthy how black the water of the lagoon appears compared to the Mediterranean in this video.

In 2019 when the previous episode of anoxia killed 300,000 kilos of fish, researchers concluded that dredging the Gola would do more harm than good and rejected the proposal at that point.

There is still significant disagreement about the benefits of dredging the gola and the Minister for Ecological Transition of the national government, Teresa Ribera, said that dredging the Marchamalo Gola would be "sacrificing the lagoon, perhaps irreversibly."

The regional government says it is prepared to take that risk, and is prepared to go ahead with the dredging without waiting for the Minsitry to prepare an environmental impact report, knowing full well that the government would not permit it to do so without one, causing inevitable confrontation.

The regional president said that if the Ministry does not give the go-ahead, he is prepared to take them to court.

Ecologists en Acción have in turn said that they will take the regional government to court if it does dredge the gola without the appropriate documentation.

We spoke to Pedro García, Director of ANSE, on Sunday morning and asked if he considered that dredging the gola would help to prevent the current level of marine life deaths, but he maintained that dredging would be totally ineffectual and would do nothing to alleviate the current situation, explaining that there were other points of interchange between the two bodies of water and the solution lay with preventing the leaching of nitrates and entry of millions of litres of fresh water every day into the lagoon.

Political inaction and the blame game, he said, was killing the Mar Menor.

Could anything be done in the short-term to quickly improve the situation he was asked, to which the answer was a simple no.

On Monday the regional president confirmed that five million litres of agricultural water run-off was continuing to enter the lagoon every single day.