Patricia Yager, associate professor of marine sciences in the Franklin College of Arts and Sciences, shared results from a recent research trip on the Amazon River with Live Science.
The Amazon River basin is the largest in the world and contains many known and unknown species and ecosystems. In order to study some of these ecosystems, research groups have to take a trip down the river and see them for themselves.
Yager specifically went to the Amazon to study the river reefs, a thriving ecosystem that was discovered in the river’s plume, meaning the area where the river meets the ocean. Plumes can impact salinity levels, pH, sedimentation, temperature, light penetration and nutrient availability for species at the mouth of the river.
“The coolest thing about these reefs is that there are corals living at least part of their year in the dark, below the turbid Amazon plume,” Yager said. “We didn’t expect that, and we are still trying to understand how their metabolism works.”
But as is the case for all ecosystems on Earth, the river plume is feeling the pressure from human interaction and degradation.
“In terms of human threats, the most immediate are oil drilling, phosphate mining and fishing pressure,” said Yager.
Even though they are part of a freshwater system, Yager says that the plume ecosystem is still subject to the changes the ocean is seeing from climate change.
“These reefs are well within the tropical surface layer, so they are also likely to be experiencing ocean warming and acidification from human-driven combustion of fossil CO2 (oil and gas). We also know that climate change is impacting the tropical water cycle and therefore the Amazon River, but we are still investigating those connections,” she said.
