The Western South Atlantic Ocean in a High-CO2 World: Current Measurement Capabilities and Perspectives

Abstract

An international multi-disciplinary group of 24 researchers met to discuss ocean acidification (OA) during the Brazilian OA Network/Surface Ocean-Lower Atmosphere Study (BrOA/SOLAS) Workshop. Fifteen members of the BrOA Network (www.broa.furg.br) authored this review. The group concluded that identifying and evaluating the regional effects of OA is impossible without understanding the natural variability of seawater carbonate systems in marine ecosystems through a series of long-term observations. Here, we show that the western South Atlantic Ocean (WSAO) lacks appropriate observations for determining regional OA effects, including the effects of OA on key sensitive Brazilian ecosystems in this area. The impacts of OA likely affect marine life in coastal and oceanic ecosystems, with further social and economic consequences for Brazil and neighboring countries. Thus, we present (i) the diversity of coastal and open ocean ecosystems in the WSAO and emphasize their roles in the marine carbon cycle and biodiversity and their vulnerabilities to OA effects; (ii) ongoing observational, experimental, and modeling efforts that investigate OA in the WSAO; and (iii) highlights of the knowledge gaps, infrastructure deficiencies, and OA-related issues in the WSAO. Finally, this review outlines long-term actions that should be taken to manage marine ecosystems in this vast and unexplored ocean region.

Ocean acidification studies and the uncertainties relevance on measurements of marine carbonate system properties

“…scripps.ucsd.edu). A regional study in the south-southeast Brazilian continental shelf agrees with this value, which has measured an average of 396.7±2.5 ppm in the atmosphere during the spring of October 2014 (Kerr et al, 2016). This enhancement is reflected in the ocean, which has absorbed about 25% to 30% of the anthropogenic atmospheric CO 2 emissions (Sabine and Tanhua, 2010;Le Quére et al, 2016).…”

“…broa.furg.br), with studies from different research areas covering different parts of the Brazilian coastline, the open ocean areas and the western South Atlantic Ocean (e.g. Longuini et al, 2015;Cotovicz et al 2016a;Kerr et al, 2016;Ito et al, 2016;Lencina-Avila et al, 2016;Orselli et al, 2018) and the Southern Ocean (e.g. Kerr et al, 2018aKerr et al, , 2018bLencina-Avila et al, 2018) (Table 2).…”

“…Thus, not only improving the knowledge concerning the OA, but also increasing the visibility of Brazil in the international scientific community. It is evident, according to the last BrOA Network publication (Kerr et al, 2016), that the Brazilian OA community is improving the data quality and technical information, even considering the distinct approaches and ecosystems, which includes: evaluation of carbonate system parameters and/or acidification in rivers (Abril et al, 2014), estuaries (Cotovicz et al, 2015Cotovicz et al 2016b), lagoons (Peixoto et al, 2013), lakes (Marotta et al, 2014;Fontes et al, 2015) DIC 10 μmol kg -1 2 μmol kg -1 pCO 2 2.5 % 0.5 % Table 1. The uncertainties of the standard carbonate system parameters for each data quality goal, weather or climate, according to Newton et al (2015).…”

Mesophotic ecosystems: Distribution, impacts and conservation in the South Atlantic

“…Regarding global environmental stressors, little is known about their effects on MEs, mainly due to the lack of long‐term monitoring. For example, ocean acidification, which is expected to accelerate in the 21st century (Hoegh‐Guldberg et al., ), compromises carbonate production by reef‐building species (e.g., calcareous algae and corals) and is the least studied global change stressor in the SAO (Kerr et al., ). Nevertheless, coralline algae are among the most important framework builders in the South Atlantic MEs.…”

Global Changes, Anthropogenic Impacts and the Future of the Oceans

“…Este cenário ilustra a importância de estudos sobre o comportamento dos organismos sob diferentes condições de pH, 82 mais séries temporais de observação dos oceanos, 83 e o uso de modelagem matemática para diminuir a incerteza nas previsões. 84 No Brasil, Kerr e colaboradores identificaram os recifes coralinos, 85 a plataforma de rodolitos (algas calcárias) ao largo dos litorais do Espírito Santo e Bahia, e as regiões de ressurgência da costa e da plataforma como áreas mais sensíveis à acidificação, apesar dos conhecimentos atuais ainda não permitirem apontar efeitos diretos. A comunidade científica brasileira é atuante neste tema através da Rede Brasileira de Pesquisa em Acidificação dos Oceanos (BrOA) 86 e vem abordando o tema no sentido de melhorar a qualidade dos dados observacionais com protocolos adotados internacionalmente, 85,87 através de experimentos com organismos para entender a resposta à acidificação [88][89][90][91] e estudos de observação na plataforma e áreas oceânicas (e.g.…”