The aquatic environment is highly complex and diverse, consisting of several types of ecosystems that are dynamic products of complex interactions between biotic and abiotic components. Changes in the physical and chemical properties of these ecosystems can significantly affect the balance of life forms present, especially in their microbiota. Among the main pollutants present in these environments are heavy metals. Several studies demonstrate the effects of these minerals on the structure and function of microbial communities, which may develop adaptation mechanisms for survival and permanence in these sites. In addition, the resistance to heavy metals may contribute to the evolution of resistance genes to the different types of antimicrobials due to the increase of the selective pressure in the environment, becoming a public health problem. One of the adaptive mechanisms present in bacteria from impacted environments that has been frequently investigated is the formation of biofilms. Recent studies have reported significant changes in the structure and amount of biofilm formed in the presence of different metals, and consequently, an increase in the tolerance to these pollutants and antimicrobials. This review will discuss the effects of some metals on bacterial biofilms and their consequences for the marine environment.
Part of the book: Bacterial Biofilms
The present review addresses the impacts of pesticides used in crops on non-target organisms in aquatic ecosystems. In recent decades, these ecosystems have received large amounts of these compounds, which are released by urban communities, rural and industrial properties. Pesticides reach the aquatic environment through different routes (leaching, irrigation, drainage, and surface runoff) and can easily reach non-target organisms, such as fish, mollusks, as well as other benthic organisms. Usually, these animals tend to undergo bioaccumulation. Exposure to these pesticides can cause numerous physiological changes by direct influence on certain cellular structures, such as on the lysosomal membrane, which can be degraded. Also, they can even react with nucleic acids resulting in several genetic injuries, thus causing adverse reactions to the body. There is a need for more incentives for the adoption of sustainable agroecological practices, as well as a ban on active ingredients harmful to the environment, in addition to strict inspection by competent environmental agencies.
Part of the book: Emerging Contaminants