Scientists recently discovered an ‘underwater rainforest’ off the coast of Brazil, near where the Amazon enters the Atlantic, and its existence has already started facing threats.
“Currently, up to 20 percent of human greenhouse gas emissions are being caused by deforestation in tropical Brazil and Indonesia, making those countries two of the highest carbon emitters in the world. It is estimated that halting forest destruction would save the same amount of carbon over the next century as stopping all fossil-fuel emissions for ten years.” These are the words of Sylvia Earle, a National Geographic oceanographer, from her 2009 book The World is Blue. Eight years down the line, while scientists are trying to understand the fate of our seas, Brazil has an opportunity to help, but it comes with a difficult choice.
Nearly 90% of the Great Barrier Reef off the western coast of Australia has undergone bleaching, a process in which the algae living symbiotically with the coral polyps are expelled. This happens because ocean waters are becoming more acidic, which in turn is happening because they’re absorbing more carbon dioxide from the atmosphere. As a result, the polyps struggle to form their calcium-rich protective structures and become vulnerable to disease. Additionally, since the polyps get most of their nutrition from their algal companions, they also begin to starve when the algae depart.
The Great Barrier Reef is a world treasure, and oceanographers are fearful about what its loss could mean for its rich and invaluable local ecosystem. In this time, the discovery of a reef system off the coast of Brazil last year has offered some hope.
The team that discovered this reef hadn’t actually been looking for corals. Patricia Yager, one of the team and a professor of oceanography and climate change from the University of Georgia, had wanted to study how the Amazon river’s plume deposits affected the ocean’s capacity to absorb carbon dioxide. They decided to go on an expedition after Rodriguo Moura, a biologist in the team, hinted at the existence of a coral reef based on a 1977 journal article.
Their findings, published in April 2016 in the journal Science Advances, were astonishing. Until this discovery, coral reefs were thought to be shoreline communities living in clearwater. This was because the algae associated with corals were believed to produce food through photosynthesis, which means they’d need sunlight wherever they were. In contrast, the corals of the Amazon reefs live in murky water thanks to sedimentary deposits carried by the river.
The team identified the reef’s lifeforms using radiocarbon dating and petrographic characterisation. The latter helps identify the composition of materials based on the minerals it contains. To identify reef-associated microorganisms, the team used metagenomic analysis, a method of collectively analysing the genomes of organisms within an environmental sample.
Yager and co. found nearly 60 species of sponges and 70 wide-ranging reef fish, along with several species of red, green and blue algae. Because sunlight doesn’t penetrate through reefs as well as it does through clearwater, the many species of algae had switched to a process called chemosynthesis. It generates energy from the chemical reactions of ammonia, nitrogen and sulphur, which the algae absorb from the environment. These findings were so unique that National Geographic called them “one of the most surprising finds in modern sea research”.
Rebecca Albright, an oceanographer and coral reef expert from the Carnegie Institution for Science, Washington DC, had told The Atlantic that the discovery of the site by itself was a big deal. “Traditionally, our understanding of reefs has focused on tropical shallow coral reefs which harbour biodiversity that rivals tropical rainforests. The new Amazonian reef system described in this paper is another example of a marginal reef that we didn’t previously know existed.”
With support from Greenpeace, the research team released the first pictures of this underwater habitat in January 2017. “Not only is the reef known all over the world, but now scientists estimate it to be five times larger than thought before.” Thiago Almeida, a campaigner affiliated with the NGO, told The Wire.
Research has clearly established how climate-change events like ocean warming and acidification affect corals. Yet there is little knowledge of how reefs influence weather and climate patterns – another reason to consider preserving them. However, there is cause for concern now. Only 10% of this unique biome has been understood yet, and scientists are already sensing a threat by companies like Total, BP, Shell, Petrobras and Brasoil, which are drilling nearby for oil. “In the past decade, a total of 80 exploratory blocks have been acquired for oil drilling in the study region, 20 of which are already producing,” Yager’s paper notes.
It added that the environmental baseline compiled by the companies and the Brazilian government is largely based on “sparse museum specimens”. Adding to concerns, one of the exploratory wells is set to operate at a depth similar to that of Deepwater Horizon, one of the world’s worst oil spills.
Moreover, these companies had submitted their risk analyses before the reef was discovered; many environmentalists are now demanding that the Brazilian government reconsider the rules of operation in these blocks. But that seems difficult. Faced with a harrowing recession and unemployment levels crossing 12%, Brazil has been soliciting foreign investment. The government of Michel Temer, the country’s president, has proposed plans to simplify environmental licensing and make it easier for companies to conduct business without the threat of lengthy delays. Where does the middle ground lie?
While a speculative estimate by the Brazilian government claims that the Foz do Amazonas basin, where the Amazon meets the Atlantic, holds up to 14 billion barrels of oil, protecting the coral reefs from drilling mishaps also offers crucial economic advantages. This is because the reefs help sequester carbon dioxide in the ocean. Reefs are to the oceans what rainforests are to land. And as biodiversity hotspots, the world’s reefs house nearly a quarter of the oceanic species; so the one off Brazil helps support fishing communities in the country’s northeast.
So how much threat does oil exploration pose? A document released by Total in June 2016 discusses the potential environmental impacts of drilling in the basin. In the text, Total acknowledges the presence of biogenic reefs in an area liable to be reached by oil under the event of a spill. However, it also claims that only a small area of the sea substrate will be exposed to even the worst leak.
Meanwhile, the Brazilian Institute of the Environment and Renewable and Natural Resources (IBAMA) has been scrutinising plans from Total for exploring near the reefs. The federal public prosecutor’s office in Amapá has recommended to IBAMA – the administrative arm of the country’s environment ministry – that it suspend oil exploration at the river’s mouth until potential impacts on the ecosystem have been fully clarified. IBAMA hasn’t ruled yet.
Samantha Joye, an oceanographer and part of Yager’s team, is also wary about biological magnification – where toxic substances from a spill could be carried by aquatic creatures through the food chain to nearby regions – and if its effects will remain in the oil cos’ blindspot. “It will not only impact corals but any animal that find home in the benthos,” she told The Wire. Total has not discussed the potential risk of this scenario, given that one of its drilling sites is only 28 km away, nor did it respond to a request for comment.
So like many developing countries in the race to become global powers, Brazil too faces a difficult road ahead: to formulate rewarding economic development plans without blowing its environmental riches. And the world watches intently.
Vishwam Sankaran is a freelance science writer.