Amazon aquatic biodiversity imperiled by oil spills

Abstract

Oil exploitation poses a significant threat to freshwater biodiversity, and future plans to develop petroleum leases in the Amazon Basin should be seem with caution. A series of oil spills have significantly affected biodiversity and human activities in some Amazonian basins, indicating that disturbances by petroleum activities will increase in the region, particularly in upper basins and river headwaters. Measures are needed to reduce the risk of spills and to minimize their impacts. More fundamentally, changes in decision making are needed that give proper weight to these impacts.

Energy development reveals blind spots for ecosystem conservation in the Amazon Basin

“…Conversely, while dams disrupt Amazonian hydrologic connectivity, this same property amplifies oil spill impacts, as rivers transport pollutants and thermally altered water far from the source point (Azevedo‐Santos et al . ). With increasing petroleum development, oil spills have become more common in the Amazon, as evidenced by disturbances along the Marañón River in 2014 and 2016 (Fraser , ; Mega ) and numerous spills in the Ecuadorian Amazon over the past 30 years (Kimerling ).…”

“…These episodes have resulted in massive fish kills, with cascading effects on other organisms through disruptions to food webs and community structure (Kingston ; Fraser ; Azevedo‐Santos et al . ). Given the possibility of toxin bioaccumulation in food webs, oil spills may have long‐lasting (>30 years) effects.…”

“…Oil development operations have had major impacts in protected areas and Indigenous territories throughout the Amazon (Figure 4; Harfoot et al 2018). The extraction of oil is associated with spills and wastewater discharge, which are damaging to terrestrial and aquatic systems (Azevedo-Santos et al 2016), often for many years after operations have ceased or following a spill (Fraser 2016(Fraser , 2018. The flaring of natural gas, which frequently rises to the surface during the oil extraction process, is intended to relieve pressure on drilling equipment but can contaminate air locally and cause forest fires (San Sebastián and Hurtig 2004).…”

“…In the Andean Amazon (the regions of Colombia, Ecuador, Peru, and Bolivia that fall within the Amazon Basin), dams are disrupting critical geomorphological processes such as river meandering and floodplain formation for thousands of kilometers downstream (Latrubesse et al 2017;Anderson et al 2018), with detrimental consequences for floodplain agriculture and fisheries (Coomes et al 2010(Coomes et al , 2016. Conversely, while dams disrupt Amazonian hydrologic connectivity, this same property amplifies oil spill impacts, as rivers transport pollutants and thermally altered water far from the source point (Azevedo-Santos et al 2016). With increasing petroleum development, oil spills have become more common in the Amazon, as evidenced by disturbances along the Marañón River in 2014 and 2016 (Fraser 2014(Fraser , 2016Mega 2016) and numerous spills in the Ecuadorian Amazon over the past 30 years (Kimerling 2013).…”

Freshwater megafauna diversity: Patterns, status and threats

“…Although the THPI shows that human impact in both the Amazon and Congo basins has not noticeably increased between 1990 and 2010 (i.e., most subcatchments within the basin have THPI values <5), threats to freshwater megafauna species are likely to be underestimated in these basins, due to a dearth of pressure data (Geldmann et al, 2014;Joppa et al, 2016). For example, 44.2% of the Amazon river basin is already protected (Abell, Lehner, Thieme, & Linke, 2016), yet freshwater megafauna species are still subject to habitat destruction, pollutants released from agriculture, mining and oil spills; particularly in the Andean Amazon region (Azevedo-Santos et al, 2016;Castello et al, 2013). In the Congo river basin, the situation is possibly worse, as the protected area coverage is lower (Abell et al, 2016), and the basin is experiencing ongoing habitat conversion due to deforestation and expansion of agricultural activities (Ernst et al, 2013;Zhou et al, 2014).…”