Occurence of polycyclic aromatic hydrocarbons in a ‘pristine' estuary of the Amazon coast (Oyapock estuary, Brazil) /

The Amazon coastal zone has been increasingly influenced by pollutants produced as a consequence of human activities over the past decades. One of these pollutants are Polycyclic Aromatic Hydrocarbons (PAHs), deriving from combustion or by direct input of oil and its byproducts. However, information about their distribution in this area is scarce, although large oil fields have been found along the Amazon coast. The aim of this study therefore was to identify the levels of PAHs in a ‘pristine' estuary of the Amazon Rainforest (Oyapock estuary) for the first time. For this purpose, 23 surface sediment samples each were taken in May 2018 and October 2018 along the estuarine gradient and analyzed in terms of their PAH concentration, short term-temporal and spatial distribution as well as their potential sources. Levels of PAHs were low, so the estuary cannot be classified as contaminated by PAHs. However, compounds classified as priority pollutants were found in all samples and future monitoring is recommended. Diagnostic ratios suggest, that most of these PAHs derived from combustion processes, but also punctual input of oil and byproducts were identified. Results of this study can now serve as a baseline in case of future contamination events.Master of Science in Marine Biological Resources (IMBRSea)The Amazon coastal zone has been increasingly influenced by pollutants produced as a consequence of human activities over the past decades. One of these pollutants are Polycyclic Aromatic Hydrocarbons (PAHs), deriving from combustion or by direct input of oil and its byproducts. However, information about their distribution in this area is scarce, although large oil fields have been found along the Amazon coast. The aim of this study therefore was to identify the levels of PAHs in a ‘pristine' estuary of the Amazon Rainforest (Oyapock estuary) for the first time. For this purpose, 23 surface sediment samples each were taken in May 2018 and October 2018 along the estuarine gradient and analyzed in terms of their PAH concentration, short term-temporal and spatial distribution as well as their potential sources. Levels of PAHs were low, so the estuary cannot be classified as contaminated by PAHs. However, compounds classified as priority pollutants were found in all samples and future monitoring is recommended. Diagnostic ratios suggest, that most of these PAHs derived from combustion processes, but also punctual input of oil and byproducts were identified. Results of this study can now serve as a baseline in case of future contamination events