Microplastic Trophic Transfer in Marine Top Predators
Microplastics are less than 5mm diameter particles that came from different sources including cosmetics, clothing and industrial processes. This synthetic particle also originates from shipping spills, polystyrene beads and fishing gear. It is widely distributed in the environment particularly in aquatic and marine ecosystems. Microplastics classify in two, first it came from direct result of human material and product used. Second it derives from the breakdown of larger plastic debris. Because microplastics do not break down for many years, it is then ingested to aquatic and marine mammals in particular. Hence, the interest of this research study is to understand the impacts of this vast microplastic on marine ecosystem. As well as on the effects of organisms health that live on it.
Ingestion of Microplastics by large Mammals
The investigation of microplastics shows an empirical evidence of the trophic transfer from fish to marine top predator. There were 12 polymer types have been detected in fish and seals wherein ethylene propylene is the most common. And the polymer found in seals varies into almost ten types maybe because of the diversity of the marine environment. The study also indicates the variations of color and sizes of microplastics detected in fish and seals. Wherein blue, red and black colors are more prominent. As a result significant range of microplastics abundance, type, size, color and polymer types are not observed only among fishes. But within the marine environment in general wherein different kinds of species thrives in.
In addition detection of microplastics depends on the process of extraction as well as coloration. Since transparent particles are less obvious because of its translucent substrate. It also indicates that harbor seal contains more plastics in stomach suggesting that non-food items trap inside especially microplastics. Indeed, the research reveals strong correlation between polymer type in both fishes and seals. Thus, signifying that the microplastics found in seals is a consequence of ingestion rather than inhalation. Also it attributes the presence of microplastics particles in seals to the amount of trophic transfer from prey to marine top predator.
Therefore, the current study presents an empirical evidence of microplastics transfers across trophic levels from fish to top marine predator mammals. It is also found out that trophic transfer represents an indirect yet a major pathway of microplastics ingestion to any species. By which the feeding mechanism is through the consumption of the whole prey including humans.
Source: Prepared by Joan Tura from Environmental Pollution
22 February 2018