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276 results on '"Costa, Rauquírio"'

17. Effects of Climate Events on the Trophic Status of an Amazonian Estuary.

Author

Monteiro, Marcela Cunha, Perreira, Luci Cajueiro Carneiro, and da Costa, Rauquírio Marinho

Subjects
RAINFALL anomalies, EL Nino, LA Nina, CLIMATE extremes, HYDROLOGY
Abstract

In recent years, climate events such as Drought, El Niño, and La Niña have become increasingly frequent and more intense. Oceanographic monitoring was used to collect hydrological data in the middle and lower sectors of the Caeté estuary in different years. Negative rainfall anomalies of up to 45% were recorded during periods marked by drought and El Niño events, which make the water in the Caeté estuary more saline and alkaline. During these events, the retention of dissolved inorganic nutrients in the middle sector appears to support increased eutrophication and more productive waters, whereas moderate eutrophication and lower productivity were observed in the lower sector. During La Niña events, by contrast, positive rainfall anomalies may reach 60%, resulting in more oxygenated water in the estuary. In addition, the lower sector tends to be more eutrophic during periods of high rainfall and freshwater discharge, as observed in this study during a La Niña event. The paucity of data on the effects of extreme climate events in Amazonian environments means that the findings of the present study may provide a useful model for the assessment of the effects of these events on other natural environments in the Amazon region. [ABSTRACT FROM AUTHOR]

Published
2024
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33. Understanding allochthonous marine litter in a protected area in the Amazon coast

Author

Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental, Universitat Politècnica de Catalunya. LIM/UPC - Laboratori d'Enginyeria Marítima, Ferreira da Silva Assis, Luciane, Cajueiro Carneiro Pereira, Luci, Jiménez Quintana, José Antonio, Ribeiro Padilha da Silva, Brenda, da Costa Pereira, Remo Marinho, da Costa, Rauquírio Marinho, Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental, Universitat Politècnica de Catalunya. LIM/UPC - Laboratori d'Enginyeria Marítima, Ferreira da Silva Assis, Luciane, Cajueiro Carneiro Pereira, Luci, Jiménez Quintana, José Antonio, Ribeiro Padilha da Silva, Brenda, da Costa Pereira, Remo Marinho, and da Costa, Rauquírio Marinho

Abstract

Studies on international waste on the Amazon coast are lacking, leaving a substantial knowledge gap concerning the socioeconomic, cultural, and environmental repercussion of this issue. In this context, the objective of this study is to comprehensively characterize and trace the origins of allochthonous litter discovered on a beach situated within a Protected Area. Given this, the hypothesis of this study is that the international litters comes from vessels operating in the region. A total of 384 containers were collected, originating from 36 countries, with those located in Asia and Africa showing the highest prevalence. Among the bottles with identified expiration dates, 76 % are newly arrived, confirming our hypothesis. The presence of older waste may result from a combination of the absence of beach cleaning public services and local dynamic processes. While international engagement is necessary, local communities, along with the scientific community, have taken proactive measures to address the problem., Peer Reviewed, Objectius de Desenvolupament Sostenible::14 - Vida Submarina, Postprint (author's final draft)

Published
2023

34. Replacement of Artemia franciscana Nauplii by Moina minuta Neonates as Live Food on the Larviculture of Angelfish (Pterophyllum scalare -Schultze, 1823) and Severum (Heros severus - Heckel, 1840)

Author

Eiras, Bruno José Corecha Fernandes, Campelo, Daniel Abreu Vasconcelos, de Moura, Lorena Batista, de Oliveira, Leonnan Carlos Carvalho, de Sousa, Liliane Marques, and da Costa, Rauquírio Marinho

Abstract

The present study aimed to assess the potential substitution of Artemia franciscana nauplii with Moina minuta neonates as the initial feed for angelfish (Pterophyllum scalare) and severum (Heros severus), evaluating the fish growth performance, live food cost, and intestinal histomorphometry. To achieve this goal, two separate experiments were carried out for each species during 20 days, using 200 postlarvae. Both experimental designs consisted of five treatments, namely, 100% A. franciscana nauplii (A100-M0); 75% A. franciscana nauplii and 25% M. minuta neonates (A75-M25); 50% A. franciscana nauplii and 50% M. minuta neonates (A50-M50); 25% A. franciscana nauplii and 75% M. minuta neonates (A25-M75); and 100% M. minuta neonates (A0-M100), with four replications (10 postlarvae per repetition). Angelfish postlarvae fed with A100-M0, A75-M25, A50-M50, and A25-M75 had better values of final length (13.31 mm, 14.15 mm, 13.32 mm, and 13.32 mm), gain in length (7.91 mm, 8.75 mm, 7.92 mm, and 7.92 mm), and length-specific growth rate (4.51% day−1, 4.82% day−1, 4.51% day−1, and 4.51% day−1). In the case of severum postlarvae, the highest length growth performance occurred in those fed with A100-M0 (15.86 mm, 8.90 mm, and 4.12% day−1), A75-M25 (15.45 mm, 8.49 mm, and 3.99% day−1), and A50-M50 (14.78 mm, 7.82 mm, and 3.76% day−1). Both species (angelfish and severum postlarvae) fed with A100-M0 and A75-M25 presented higher values of final weight (28.88 mg and 34.49 mg; 55.84 mg and 53.95 mg), gain in weight (27.56 mg and 33.08 mg; 51.03 mg and 49.14 mg), and weight-specific growth rate (15.42% day−1 and 16.30% day−1; 12.26% day−1 and 12.09% day−1). Live food cost for angelfish and severum postlarvae was higher in A100-M0 (US$ 0.92 and US$ 1.08) and lower for the ones in A0-M100 (US$ 0.36 and US$ 0.35). Severum postlarvae fed with A100-M0 (57.20 µm), A75-M25 (55.66 µm), and A50-M50 (54.27 µm) presented the highest intestinal villi heights. Thus, partial replacement of A. franciscana nauplii by M. minuta neonates in the proportion of A75-M25 or 100A-0M is viable and effective during the first feed of these fish species.

Published
2023
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