To define the measurable pollution footprint that mankind has on the natural environment and its corresponding biogeochemical cycles for the past 3 centuries, Paul Crutzen and Eugene Stoermer conceptualised the term ‘Anthropocene’ to define this epoch. Apart from plastic pollution, chemical pollution which is defined as the contamination of marine environment with anthrop0genic and harmful pollutants also has deleterious implications on ocean health.

Chemical pollutants are especially insidious as they exacerbate chemical bioaccumulation in marine food webs through the introduction of excessive metals, toxins and nutrients into marine environments. This can often take the form of illegal dumping which generates releases of hazardous chemicals to land, air and water. According to Big Blue Ocean Cleanup (undated), the most ubiquitous form of chemical contamination is via estuary and river systems. Chemical pollutants often leak into nearby estuaries, streams and rivers by rainwater which are then transferred into oceans as its vastness allows for easy contaminant entry, facilitating greater visibility in coastal and marine environments and for more meaningful sediment core analysis (Logemann et al., 2022).

These chemical pollutants mostly originate from non-ocean sources – 80% of chemical pollution is from land! In fact, agricultural and urban activities are largely responsible for a majority of the commercial, industrial and recreational contaminates that are deposited in our oceans from poor water treatment works and sewage leaks. Other non-oceanic sources include the atmosphere where chemical pollutants such as CFCs, acid rain eventually culminates in ocean acidification. These stem from industrial activities such as coal-fired power stations and fossil fuel production that emit hazardous pollutants into the atmosphere yearly. According to OceanProtect.org (2019), other anthropogenic activity such as the fuel combustion in automobiles and factories launch heavy metals and hydrocarbons into the atmosphere. Once airborne, these pollutants are washed out by snow/rain events and eventually fall back into the oceans.

However. this does not mean that ocean-based pollution does not exist. Oil spills, one of the most common forms of marine pollution occurs when spills and urban-based runoff discharges fuel from passing ships or port disruptions. Lloyd-Smith and Imig (2018) elucidate how oil discharge from boats makes up 24% of the total oil in the ocean, of which 8% of overall oil production is generated from spills during production/transportation. Edmond (2021) highlights how oil spills are one of the most harmful forms of chemical pollution as toxic chemicals leached from the disaster can remain in the ocean for years after the catastrophe. Not only does this disaster have fatal implications for the animals it engulfs, it also poisons the sediment. Hence, this increases the toxic levels of the ocean and causes irreparable damage to marine environment.

Stay around for the next few posts where more examples of chemical pollution in the marine environment will be discussed 🙂

 

References

Logemann, A., Reininghaus, M., Schmidt, M., Ebeling, A., Zimmermann, T., Wolschke, H., Friedrich, J., Brockmeyer, B., Pröfrock, D. and Witt, G., 2022. Assessing the chemical anthropocene – Development of the legacy pollution fingerprint in the North Sea during the last century. Environmental Pollution, 302, p.119040.