The development of ecosystems is affected by various physical, biological, and chemical agents, and these effects can be both positive and negative. It is noteworthy that in the majority of cases this is an adverse impact. For instance, such physical agents as oil spills or surface plastic debris can be harmful to marine mammals due to the risks of ingestion and entanglement (Law et al., 2014). These hazards are also associated with the impact of various biological agents as plastic debris can transport new species. Spilled oil prevents marine mammals from breathing properly, which may cause many animals’ deaths. Such chemical agents as pathogens (transported with plastic debris) often affect marine mammals who die or have to leave the contaminated areas. Finally, pharmaceuticals release various chemicals that can affect the development of marine mammals (Gaw, Thomas, & Hutchinson, 2014). For instance, it has been found that many marine mammals have developed high antibiotic resistance. Importantly, pharmaceuticals in many parts of the world often release dangerous chemicals that contaminate water and cause the death of marine mammals or their migration to other areas.
References
Gaw, S., Thomas, K., & Hutchinson, T. (2014). Sources, impacts, and trends of pharmaceuticals in the marine and coastal environment. Philosophical Transactions of the Royal Society B: Biological sciences, 369(1656), 1-11.
Law, K., Morét-Ferguson, S., Goodwin, D., Zettler, E., DeForce, E., Kukulka, T., & Proskurowski, G. (2014). Distribution of surface plastic debris in the Eastern Pacific Ocean from an 11-year data set. Environmental Science & Technology, 48(9), 4732-4738.