Combined effects of the insecticide Fipronil (REGENT® 800WG) and climate change factors on the metabolism of the benthic fish Solea senegalensis

Abstract

Human activities have been considered the main causes of climate change (CC) observed in the world and effects of increases temperature, acidification and salinity in marine water bodies have been reported in benthonic fish. In the fish Solea senegalensis, for example, the water temperature is a basic abiotic factor that regulates its physiology and metabolism, since it inhabits coastal and estuarine areas under severe changes of temperature and salinity, and is exposed to many substances derived from wastewaters that reach the sea. Besides that, changes in physical parameters may modify the interaction potential of chemical compounds and significantly change their disposal and action in the aquatic environment, increasing the consequences of exposures to marine organisms, being therefore, necessary to understand the risks of the interaction of environmental stressors in humans and wildlife health. Fipronil is one of the insecticides most used in crops of maize, rice and in the treatment of seeds for the planting of sunflower in Europe and is classified as highly toxic. Although banned from the European Union, Spain continues to use the product. Some studies have demonstrated the potential action of Fipronil as an endocrine disrupter in various organisms such as fish, crustaceans, mammals. For fish, alterations in the endocrine system by environmental estrogens cause great concern, since the mechanisms of action in the reproductive function involve disruption in the production and action of natural hormones, because they bind to the estrogen receptor and alter the reproductive function in exposed organisms. Thus, exposure to environmental estrogens may impair the adaptability of the benthic species to adequately respond to variables influenced by CC, such as changes in temperature and pH. This study aims to identify the sensitivity of the species S. senegalensis in terms of energy needs as consequence of climate changes (changes in temperature and pH), including the additional effect of another stress factor, such as exposure to Fipronil. For this, parameters involved in xenobiotic biotransformation, endocrine disruption, antioxidant defenses and others energy related metabolic processes will be analyzed. (AU)