Number of species described on the Brazilian coast could reach 13,000

2013 BIOTA-FAPESP Education Cycle of Conferences discusses coastal and marine biodiversity.

By Karina Toledo

Agência FAPESP – The most recent review of South America’s coastal and marine biodiversity, published in 2011 in the journal PLoS One, reported that 9,103 species of animals, plants and algae are present in Brazilian waters. However, this number could reach nearly 13,000, according to Maria de los Angeles Gasalla, a faculty member at the Universidade de São Paulo’s Oceanography Institute (IOS/USP).

Gasalla made this claim during the penultimate meeting of the 2013 BIOTA-FAPESP Education Cycle of Conferences, organized by the Research Program for Characterization, Conservation, Recovery and Sustainable Usage of Biodiversity in São Paulo (BIOTA), held on October 24. Gasalla compared species numbers from recent reviews conducted by Brazilian researchers with the data from the PLoS One article, by Patricia Miloslavich, a researcher at Venezuela’s Simón Bolívar University, and her colleagues.

The study coordinated by Miloslavich covered both the Atlantic and the Pacific coasts of South America and was conducted under the auspices of the international project known as the Marine Life Census, which began in 2000 and took nearly ten years to complete.

In studying the Brazilian maritime region, the project highlighted crustaceans, with 1,966 known species, as having the greatest diversity in the region, followed by mollusks (1,833 species), fish (1,294 species) and polychaetes (987 species). Together, according to the article, these groups make up 66.79% of the known marine biota in Brazil.

“These numbers initially seemed higher than previous estimates. But upon in-depth analysis of the article, we realized that they are underestimates. Adding the data from studies recently conducted by Brazilian researchers, we reached 10,804 different species solely related to marine fauna. If we also consider the flora, the number could reach somewhere near 13,000 species,” affirmed Gasalla.

According to the literature review compiled by Gasalla, the number of crustacean species described on the Brazilian coast could reach 3,335. Additionally, there are 1,886 known species of mollusks, 1,420 known species of fish and 987 known species of polychaetes.

Scientists are unsure what percentage of the marine biota in Brazil is still unknown. It is thought, however, that the percentage is very high and that many species could disappear before ever being discovered. Anthropic pressures—the consequences of human activities, such as pollution, degradation of habitats by economic developments, uncontrolled expansion of tourism, the introduction of exotic species and unregulated fisheries—are considered to be among the main threats to biodiversity on the so-called Blue Amazonia (the Brazilian coast).

The country’s marine zone originally covered an area of 3.5 million square kilometers. With the extension of the continental platform, as requested by the United Nations in the past decade, the Blue Amazonia now spans 4.5 million km2.

A study presented by the Environment Ministry in 2010 indicated that 40% of this territory corresponds to regions that have been deemed priority areas for conservation of biodiversity. Still, according to Gasalla, only 1.87% of the Brazilian marine zone is protected in Conservation Units, and some 10% have been licensed for natural gas and oil exploration.

“If only the original 3.5 million km2 of the marine zone is considered, the percentage of protected areas reaches 1.87%; if the new span is considered, the number is even smaller. Furthermore, some studies show that several conservation units were not carefully demarcated during implementation, and some exist only on paper but in practice do not function,” explained the researcher.

One of the targets established during the Conference of Parties (COP 10) to the Convention on Biological Diversity (CBD), held in the Aichi, Japan, is that by 2020, at least half of the marine and coastal areas considered of special importance for biodiversity and ecosystem services will be included in systems of protected areas.

“It’s useless, therefore, to create protected areas by decree to supposedly meet the established targets. Part of the conservation policy should work hand in hand with scientific fundamentals and social context. The process should be based on scientific knowledge, in addition to effectively involving local communities that utilize the sea as a means of survival, because, on the contrary, in addition to not working, it [implementing the process] could create bigger problems,” warns Gasalla.

Gasalla also mentioned the sustainable use of natural marine resources to meet human food needs and income through fishing and aquaculture. The professor emphasized the importance of management with clear objectives for fish and aquaculture to guarantee a sustainable level of marine life, to mitigate collateral impacts, and to ensure economic feasibility and social equality.

Climate change

Another topic debated by participants of the penultimate meeting of the BIOTA-FAPESP Education 2013 Cycle of Conferences was the fact that the priority conservation areas could change in the next few years because of climate change.

“With the heating of marine waters, some species could migrate to colder regions, for example. We are currently discussing the possibility of creating mobile protection areas in the oceans,” affirmed Mariana Cabral de Oliveira, a researcher at USP’s Biosciences Institute.

Furthermore, Oliveira emphasized, the acidification of waters—which is also a result of increases in carbon dioxide emissions (CO2)—could sharply impact calcareous algae species, known as rhodoliths, that are found mainly in the region around Espírito Santo and the Abrolhos Platform on the coast of Bahia.

According to an article published by Brazilian researchers in PLoS One in 2012, the banks of rhodoliths in Abrolhos cover an area of more than 20,000 square kilometers, which is comparable to the area of the state of Sergipe or the area of the Great Barrier Reef in Australia.

Each rhodolith functions as a mini-reef, serving as a home for small invertebrates. “Some deposits of rhodoliths are dozens of meters in depth. Some algae have a tough wall with calcium carbonate deposition, which grows layer upon layer. In this process, the alga capture CO2 from the atmosphere,” explained Oliveira.

The acidification of the oceans has not only impeded the process of calcification of algae but could dissolve the existing calcareous walls, causing the trapped CO2 to be released into the atmosphere once again, warns Oliveira. “There is an estimated 200 billion tons of calcium carbonate in these rhodolith deposits in Brazil, which corresponds to 88 billion tons of CO2. Clearly this will not be released all at once since some deposits are very deep, and the action occurs from the bottom up,” she explained.

The third speaker was Roberto Berlinck, a faculty member at USP’s São Carlos Chemistry Institute (IQSC/USP), who described several molecules with pharmacological activity that have been isolated from marine organisms. Among the examples mentioned was squalimine, isolated from the shark species Squalus acanthias, which has antifungal and antitumor activity. Berlinck also discussed pseudopterosine, an anti-inflammatory molecule produced by corals of the species Pseudopterogorgia elisabethae, which is used in a cosmetics line.

Berlinck also stressed the great lack of knowledge of marine microbiota around the world. According to Berlinck, it was only in 2002 that the first portrayals of microbial marine diversity began to appear because bacteria in marine environments are extremely hard to grow using traditional techniques.

“American researchers developed special methods to isolate these microorganisms and discovered that a single taxon, the SAR11 group of bacteria, corresponds to 40% of marine bacterial cells. It’s incredible,” affirmed Berlinck.

The last meeting of the 2013 Cycle of Conferences will be held on November 21 and will focus on the theme “Biodiversity in Anthropic Environments—Urban and Rural.” The initiative has the objective of contributing to improving science learning.