A research team in Bergin has reported finding plastics in the livers of European anchovies (Collard et al. 2017).
Since the 1950s, we have been producing massive amounts of plastic and keep polluting the ocean, beach, river, lake and aquatic ecosystems. Plastics have been found even in uninhabitable polar regions (Lusher et al. 2015).
Plastic materials are broken up by waves and sunlight and form microplastics and nanoplastics (Andrady et al. 2003, Barnes et al. 2009), which are less than 5mm and 1µm in diameter, respectively (Cole & Galloway 2015).
By 2017, microplastics were found in the stomachs of marine life (Anastasopoulou et al. 2013, Foekema et al. 2013, Lusher et al. 2015, Romeo et al. 2015, Romeo et al. 2016, Neves et al. 2015). Recent research indicates that anchovies identify plastics as food, because microplastics absorb the scent of plankton (Savoca et al. 2017).
We are not clear about to what extent microplastics have a negative impact on marine life; in actual fact, however, we are very worried about ingesting such particles via fish.
The shocking thing is that plastics have somehow ended up in organs through the alimentary canal. Researchers have stated that in experiments, polyethylene fragments (approximately 125-440µm) ended up in the livers of European anchovies (Collard et al. 2017).
Microplastics have been detected in the livers of European pilchard and Atlantic herring (Collard et al. 2017).
Plastic particles ranging from 0.1mm to 1mm were exposed to mullets, wearing away to 0.2 to 0.6 mm in size and ending up in their livers (Avio et al. 2015).
The reason plastics are carried to livers may be because microplastics become extremely tiny nanoplastics and can thus pass through the gut wall, after which they flocculate to become microplastics again in the liver (Collard et al. 2017).
In the case of a similar experiment, where medaka (Japanese rice fish) were exposed to nanoplastics (40 nm polystyrene), scientists detected plastic fragments in their intestines, testis and livers (Kashiwada 2006). It is supposed that these plastic particles enter the blood through their alimentary canal epithelia and their gills and are carried further from there (Kashiwada 2006).