Invasive fish and their impacts gain strength as the planet warms

Tilapa is one of the fish that accumulates impacts aonwaramis / iNaturalist Invasive fish are modifying the functioning of aquatic ecosystems in different regions of the planet, and the effects could become even more intense as the climate warms. The conclusion is from a study published in the scientific journal Global Change Biology, one of the main international publications in the field of Ecology. ? Also follow Terra da Gente on Instagram Led by the Federal University of São Carlos (UFSCar), the research gathered data from 636,980 fish, distributed in 667 communities in 402 lakes located in Brazil, Canada, France and Spain. According to the researchers, communities under greater pressure from invasive species present important changes in the size structure of fish and the biomass of native species, modifying ecological processes that are fundamental to the functioning of aquatic environments. According to the authors, "the study strengthens our ability to anticipate the impact of biological invasions on freshwater communities and their ecosystem services in a scenario of global change." See more news from Terra da Gente, on g1: CUTE: Six endangered marmoset babies are born in a unique center in the world DISCOVERY: After 12 years of mystery, scientists identify a new plant in Brazil FLAGRAM: Video records the song of the Guianan marmoset in a preserved area in Pará Invaders change the way lakes work A carp swims on the surface of a pond in the Palmengarten park in Frankfurt, Germany Michael Probst/AP The researchers analyzed data collected between 2001 and 2024 in natural lakes and reservoirs. In total, 404 fish species were evaluated, allowing us to analyze communities where native and non-native species coexist under different levels of invasion. The work shows that the greater the presence of invasive species, the greater the change in the structure of aquatic communities. This means that the distribution between small and large fish no longer follows the pattern normally expected by Ecology, affecting the flow of energy within the ecosystem. The authors explain that invasive fish occupy different ecological roles and can profoundly alter the organization of communities through predation, competition for food and space and, indirectly, through changes in habitat conditions. The effect changes depending on the temperature One of the main results of the research is that the impact of invasions depends on the temperature of the environment. In warmer lakes, predatory invasive fish exert greater pressure on small individuals and juveniles. According to the study, higher temperatures increase the metabolic demand and feeding activity of these predators, favoring the capture of smaller prey and altering the structure of native communities. In colder environments, the dominant effect is different. Invasive species that occupy lower trophic levels compete for resources such as food, shelter and areas used by native species, mainly reducing their biomass. As the researchers summarize, "non-native species at lower trophic levels may have even greater impacts than piscivorous fish by reshaping community structure and reducing the biomass of native species." See what's highlighted in g1: