Although the introduction of exotic species is one of the main causes of the loss of native biodiversity in aquatic ecosystems, Governor Enrique Alfaro Ramírez contributed to this practice on June 15 by releasing some of the 250,000 fish he said would be sown in Lake Chapala as carp, catfish, and tilapia, which correspond to invasive species of the most distributed in the bodies of water of the Central Plateau of Mexico.
Although Chapala is one of the lakes richest in aquatic fauna endemism, with 79 percent of the fish exclusive to this ecosystem, according to the National Commission for the Knowledge and Use of Biodiversity (Conabio), at least 10 are critical danger of extinction, or perhaps already disappeared, by pollution, overexploitation of fisheries and the introduction of exotic species that displace them.
Some endemic representatives of Chapala are whitefish, which includes several species of the genus before Chirostoma , today Menidia , which comprises medium-sized fish and shrimp, highly exploited during the last century, and a species of lamprey, a primitive fish parasite of fish white that, because of its decline, also has not been seen for years.
According to the scientific article Invasive fish in the Center of Mexico, of the Conabio, the introduction of Asian carp and African tilapia for commercial aquaculture purposes, as well as another thirty invasive species, has meant an increasing problem due to its promotion by the federal and state governments that do not weigh the environmental impact of it, so it calls to practice also the breeding and planting of native species so as not to lose biodiversity, especially if it is endemic that is being displaced.
“The introduction of exotic species is among the most important, least controlled and least reversible impacts that occur in ecosystems and that greatly affect their biodiversity, biogeochemistry and economic uses,” said the publication.
“A good example of this situation is the largest lake in Mexico, Chapala, which has an area of one thousand 100 square kilometers and which houses six species of charales, three of white fish, as well as other endemic species such as Ictalurus ochoterenai , I. dugesii , Yuriria chapalae , Algansea popoche andTetrapleurodon spadiceus (lamprey), many of which are at risk of extinction, but which, despite this situation, due to social pressures are planted with exotic species, mainly tilapia and carps “, adds .
On June 15, Enrique Alfaro visited Chapala to announce the implementation of a master plan for the economic and environmental recovery of the lake “without occurrences”, however, he posted a video on his social networks where he is seen introducing exotic specimens, which damage the ecological balance of the declared aquatic ecosystem Ramsar Site.
Chapala The introduction of exotic species is among the most important, least controlled and least reversible impacts that occur in ecosystems.
Biodiversity of Chapala
48 species of fish
30 species are endemic
10 could be close to disappearing
Importance of the lamprey
The lamprey of Chapala ( Tetrapleurodon spadiceus ) is an endemic species of primitive fish that instead of jaw and teeth has a circular suctor apparatus that allows it to adhere to the body of the host fish, that is to say, they are parasitized, and feeds on its blood
Parasites almost exclusively white fish that is probably extinct, the lamprey is also about to disappear, and although it is a parasite is beneficial to the ecosystem, it controls populations and its presence is an indicator of wildlife abundance
The Mazatlan Post