The Blue Shark and Ocean Pollution

Additional studies were done on another endangered species, blue sharks. The blue shark is a oceanic and pelagic species found in the mediterranean sea. The blue shark migrates vast distances of water for feeding and reproduction, therefore, it faces various areas with distinct species. The aim of this study was to also examine plastic ingestion in blue sharks from the north western mediterranean through analyzing the stomach contents and quantifying the litter ingested. The study was done by collecting 139 blue sharks from the year 1999 to 2015 in the offshore area of the mediterranean sea. The total length, weight and sex of the sharks were then measured and recorded. After necropsy, a microscope was used to identify the collected stomach content. The dried plastic items were then analyzed using the spectroscopy technique to find the poly composition of the plastic and grouped. The ingested plastics collected were grouped according to characteristics of total plastics items, plastic size and lastly plastic color. The experiment resulted in polyethylene and polypropylene being the most abundant. Regarding size, mesoplastics were predominant in both juvenile and adult sharks. Lastley, the plastic debris color tended to vary due to sharks opportunistic feeding strategy (3).

A further study was done on ingestion of polystyrene microplastics in marine life brine shrimp, artemia parthenogenica. The study demonstrated the toxic effects of microplastic ingestion specifically in filter feeders. The purpose of the study was to quantify the lowest concentration of polystyrene microsphere where ingestion could be seen at the two time periods of 24 hours and 14 days as well as examine the effects of microsphere exposure on the intestinal epithelial cells (2). Subsequently, when the artemia were exposed to the microspheres, regarding concentration, it was concluded that it was environmentally relevant as well as needed further research to be determined specifically. However, the pollutant lead to change in morphological appearance of digestive tract epithelial cells as wells as disordered microvilli in intestine.

The last study was conducted on the effects of microplastic exposure on growth and development of crepidula onyx. In this experiment the purpose was to expose the C. onyx larvae to different concentrations of microplastic and measure the effects it has on the development. It was shown that at high concentration, larvae that were fed micro-PS resulted in slower growth compared to the control group (4). All in all, the multiple studies discussed, provide enough evidence to illustrate the significant impact of plastic within our ecosystem among different trophic levels. Unfortunately, as the population grows, the demand for the use of plastic increases as well. However, there are many ways to decrease the usage of plastics by starting with reduce, reuse and recycle as well as using reusable straws, cloth bags instead of plastic and decreasing littering. As a population, it is in our hands to make a difference by making small changes within our daily lifestyle.

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