Early warning indicators of decadal shifts in the planktonic assemblage of the Cabo Frio upwelling ecosystem Thiago da S. Matos, Carolina S. dos Reis, Laura de A. Moura, Andressa C. de Souza, Ana Carolina N. Luz, Vanessa T. Bittar, Yuri Artioli, Guillem Chust, Patrizio Mariani, Tania O. Oda, Amanda R. Rodrigues, Maria A. Gasalla, Ricardo Coutinho, Lohengrin Fernandes Ecological Indicators, 2024 A temporal regime shift in the ecosystem is characterized by changing temperature and salinity, followed by a shift in the ratio of diatom-to-dinoflagellate and copepod-to-cladoceran. • A planktonic community change occurred associated with a decadal environmental shift. • The proportion of copepods and diatoms relative to cladocerans and dinoflagellates is being diminished in the CFUS. • Long temporal trends of temperature and salinity are likely promoting dinoflagellates and cladocerans. • A cascade effect is expected in the local food web in the next years. Long-term monitoring of coupled environmental and biological components in upwelling ecosystems is critical for early warning under the global warming context. Temperature, salinity, nutrients, and plankton populations are promising indicators of the ecosystem state that help us to address the current status of the oceans and construct better predictions for the future. The Cabo Frio Upwelling System (CFUS) is a regionally productive wind-driven coastal upwelling ecosystem on the northern boundary of the South Brazilian Shelf sustaining diverse marine life including large stocks of fish and squid. Like other cold marine ecosystems, most of its functioning is likely threatened by ocean warming which emphasizes the need for ecological indicators. This study aimed to analyze the causal relationships between the temporal changes in the physical and chemical properties and the dominant planktonic communities leveraging long-term observations (20 years). The results suggested a link between the temporal changes in the ecosystem conditions and the composition of the plankton assemblage, notably an increasing proportion of dinoflagellates relative to diatoms and cladocerans relative to copepods. This increase in the proportional abundance of dinoflagellates and cladocerans over time suggests a regime shift in the plankton assemblages during the 2000s, highlighting some large phytoplankton and zooplankton groups as early indicators of productivity shifts in upwelling ecosystems.
Carbonate system in the Cabo Frio upwelling Carlos Augusto Ramos e Silva, Livia Viana de Godoy Fernandes, Flavo Elano Soares de Souza, Humberto Marotta, Flavio da Costa Fernandes, Thaise Machado Senez Mello, Nicole Silva Caliman Monteiro, Anderson Araújo Rocha, Ricardo Coutinho, Lohengrin Dias de Almeida Fernandes, Raimundo Nonato Damasceno, Ludmila Caetano dos Santos Scientific Reports, 2023 The quantitative assessment of the carbonate system represents one of the biggest challenges toward the "Sustainable Development Goals" defined by the United Nations in 2015. In this sense, the present study investigated the Spatio-temporal dynamics of the carbonate system and the effects of the El Niño and La Niña phenomena over the Cabo Frio upwelling area. The physical characterization of the site was carried out through data on wind speed and sea surface temperature. Water samples were also collected during the oceanographic cruise onboard the Diadorim R/V (Research Vessel). From these samples, the parameters of absolute and practical salinity, density, pH, total alkalinity, carbonate, calcite, aragonite, bicarbonate dissolved inorganic carbon, carbon dioxide, partial pressure of carbon, calcium, and total boron were obtained. The highest average concentration of bicarbonate in S1 (2018 µmol/kg) seems to contribute to the dissolved inorganic carbon values (2203 µmol/kg). The values of calcite saturation state, aragonite saturation state, and carbonate were higher on the surface of each station (calcite saturation state = 4.80–5.48; aragonite saturation state = 3.10–3.63, and carbonate = 189–216 µmol/kg). The mean values of pH were similar in the day/night samples (7.96/7.97). The whole carbonate system was calculated through thermodynamic modeling with the Marine Chemical Analysis (AQM) program loaded with the results of the following parameters: temperature, salinity, total alkalinity, and pH parameters. This manuscript presents original data on the carbonate system and the "acidification" process influenced by the Cabo Frio upwelling, which directly depends on the El Niño and La Niña phenomena oscillations in the sea surface temperature.
Seasonal Changes in the Size Distribution of Copepods Is Affected by Coastal Upwelling Judson Rosa, Thiago Matos, Débora da Silva, Carolina Reis, Cristina Dias, Tatiana Konno, Lohengrin Fernandes Diversity, 2023 Water temperature controls the physiology, growth rate, distribution, and behavior of most plankton populations in the sea and thus affects the energy transfer in marine ecosystems. The present study focuses on the influence of seasonal changes in sea surface temperature on phytoplankton and the size distribution of copepods in the Arraial do Cabo Upwelling System (Brazil), where a wind-driven coastal upwelling can lead to multiple distinct bottom-up cascade effects on the food web. To address the potential effect of the seasonal changes, environmental data were obtained and the abundance of plankton determined from monthly samples collected in triplicate from 2010 to 2014. The samples were analyzed on a Benchtop FlowCAM (FC), and copepods (<1000 µm) were classified according to their Ellipses Equivalent Major Axis using image analysis software ImageJ (IJ). For IJ analysis, a batch-processing macro was built to open all FC raw images and then crop each copepod individually into a single picture. Using these images, prosome and urosome lengths were manually measured with the straight-line tool in IJ. With the combinations of measurements obtained in the IJ adjusted as FC measurements, we established a new, faster, and more effective way to measure copepods. With the copepod size classification, we found that there is a cycle in copepod size combined with the upwelling cycle that is related to temperature rather than to phytoplankton growth. Copepod abundance as a whole peaked during the autumn, winter, and spring seasons. The method performed here proved that FC is an effective tool for classifying copepod sizes and detecting seasonal variation.
Effects of dredging activities and seasonal variation on coastal plankton assemblages: results from 10 years of environmental monitoring Lohengrin D. A. Fernandes, Guilherme N. Corte, Laura Moura, Carolina Reis, Thiago Matos, Danubia Moreno, Pedro Sant’ Anna Cortez, Wanderson Fernandes de Carvalho, Wanda Monteiro-Ribas, José Eduardo A. Gonçalves, Fernando Ribeiro, Fernanda Thomazelli, Nafisa Rizzini-Ansari, Eduardo Barros Fagundes Neto, Luiz Ricardo Gaelzer, Elizabeth de Souza Martins, Márcio Martins Lobão, Maria Helena Baeta-Neves, Ricardo Coutinho Environmental Monitoring and Assessment, 2023
Long-term monitoring projects of Brazilian marine and coastal ecosystems Cesar A.M.M. Cordeiro, Anaide W. Aued, Francisco Barros, Alex C. Bastos, Mariana Bender, Thiago C. Mendes, Joel C. Creed, Igor C.S. Cruz, Murilo S. Dias, Lohengrin D.A. Fernandes, Ricardo Coutinho, José E.A. Gonçalves, Sergio R. Floeter, Juliana Mello-Fonseca, Andrea S. Freire, Douglas F.M. Gherardi, Luiz E.O. Gomes, Fabíola Lacerda, Rodrigo L. Martins, Guilherme O. Longo, Ana Carolina Mazzuco, Rafael Menezes, José H. Muelbert, Rodolfo Paranhos, Juan P. Quimbayo, Jean L. Valentin, Carlos E.L. Ferreira Peerj, 2022 Biodiversity assessment is a mandatory task for sustainable and adaptive management for the next decade, and long-term ecological monitoring programs are a cornerstone for understanding changes in ecosystems. The Brazilian Long-Term Ecological Research Program (PELD) is an integrated effort model supported by public funds that finance ecological studies at 34 locations. By interviewing and compiling data from project coordinators, we assessed monitoring efforts, targeting biological groups and scientific production from nine PELD projects encompassing coastal lagoons to mesophotic reefs and oceanic islands. Reef environments and fish groups were the most often studied within the long-term projects. PELD projects covered priority areas for conservation but missed sensitive areas close to large cities, as well as underrepresenting ecosystems on the North and Northeast Brazilian coast. Long-term monitoring projects in marine and coastal environments in Brazil are recent (<5 years), not yet integrated as a network, but scientifically productive with considerable relevance for academic and human resources training. Scientific production increased exponentially with project age, despite interruption and shortage of funding during their history. From our diagnosis, we recommend some actions to fill in observed gaps, such as: enhancing projects’ collaboration and integration; focusing on priority regions for new projects; broadening the scope of monitored variables; and, maintenance of funding for existing projects.
Multi-scale temporal variation of marine femtoplankton and picophytoplankton: the role of size and environment Carolina Reis, Guilherme Corte, Lohengrin Fernandes Ocean and Coastal Research, 2022 Femtoplankton and picophytoplankton organisms exert a major role in the balance between producers and consumers and are responsible for a large part of net primary production in the ocean. However, despite their ecological importance, the magnitude and drivers of their temporal dynamics remain largely unexplored. To address this significant knowledge gap, we performed weekly sampling over ten months in a wind-driven coastal upwelling area in the subtropical South Atlantic Ocean. We combined this intensive feldwork with multi-color fow cytometry and statistical modeling to investigate the temporal changes of both femto- and picophytoplankton at multiple temporal scales. We found that femtoplanktonic organisms (including virus-like particles) responded faster (i.e., without a temporal lag) to environmental changes, mainly related to chlorophyll-a (chl-a) and phaeopigment variations. On the other hand, picophytoplanktonic organisms showed a slower response to environmental changes, with positive responses to variation in pH and NH4 concentrations after a one-week lag. Overall, our results demonstrate that the speed of response of planktonic organisms to environmental changes may be dependent on their size, which highlights the importance of environmental variables and biological interactions as drivers of their temporal dynamics.
Inter-annual cascade effect on marine food web: A benthic pathway lagging nutrient supply to pelagic fish stock Lohengrin Dias de Almeida Fernandes, Eduardo Barros Fagundes Netto, Ricardo Coutinho, and Plos One, 2017 Currently, spatial and temporal changes in nutrients availability, marine planktonic, and fish communities are best described on a shorter than inter-annual (seasonal) scale, primarily because the simultaneous year-to-year variations in physical, chemical, and biological parameters are very complex. The limited availability of time series datasets furnishing simultaneous evaluations of temperature, nutrients, plankton, and fish have limited our ability to describe and to predict variability related to short-term process, as species-specific phenology and environmental seasonality. In the present study, we combine a computational time series analysis on a 15-year (1995–2009) weekly-sampled time series (high-resolution long-term time series, 780 weeks) with an Autoregressive Distributed Lag Model to track non-seasonal changes in 10 potentially related parameters: sea surface temperature, nutrient concentrations (NO2, NO3, NH4 and PO4), phytoplankton biomass (as in situ chlorophyll a biomass), meroplankton (barnacle and mussel larvae), and fish abundance (Mugil liza and Caranx latus). Our data demonstrate for the first time that highly intense and frequent upwelling years initiate a huge energy flux that is not fully transmitted through classical size-structured food web by bottom-up stimulus but through additional ontogenetic steps. A delayed inter-annual sequential effect from phytoplankton up to top predators as carnivorous fishes is expected if most of energy is trapped into benthic filter feeding organisms and their larval forms. These sequential events can explain major changes in ecosystem food web that were not predicted in previous short-term models.