cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.5667424.v1
title: Marine substrate response from the analysis of seismic attributes in CHIRP sub-bottom profiles

description: Abstract This paper presents an evaluation of the response of seismic reflection attributes in different types of marine substrate (rock, shallow gas, sediments) using seafloor samples for ground-truth statistical comparisons. The data analyzed include seismic reflection profiles collected using two CHIRP subbottom profilers (Edgetech Model 3100 SB-216S), with frequency ranging between 2 and 16 kHz, and a number (38) of sediment samples collected from the seafloor. The statistical method used to discriminate between different substratum responses was the non-parametric Kruskal-Wallis analysis, carried out in two steps: 1) comparison of Seismic Attributes between different marine substrates (unconsolidated sediments, rock and shallow gas); 2) comparison of Seismic Attributes between different sediment classes in seafloors characterized by unconsolidated sediments (subdivided according to sorting). These analyses suggest that amplitude-related attributes were effective in discriminating between sediment and gassy/rocky substratum, but did not differentiate between rocks and shallow gas. On the other hand, the Instantaneous Frequency attribute was effective in differentiating sediments, rocks and shallow gas, with sediment showing higher frequency range, rock an intermediate range, and shallow gas the lowest response. Regarding grain-size classes and sorting, statistical analysis discriminated between two distinct groups of samples, the SVFS (silt and very fine sand) and the SFMC (fine, medium and coarse sand) groups. Using a Spearman coefficient, it was found that the Instantaneous Amplitude was more efficient in distinguishing between the two groups. None of the attributes was able to distinguish between the closest grain size classes such as those of silt and very fine sand.
DOI: 10.6084/m9.figshare.5667145
title: Spatial and seasonal variation of microphytoplankton community and the correlation with environmental parameters in a hypereutrophic tropical estuary - Maranhão - Brazil

description: Abstract The Bacanga River Estuary has a hydrodynamic behavior and its tidal flow is limited by a dam. It is considered as a hypertrophic environment that receives daily high loads of domestic sewage without treatment. This study aimed to evaluate the spatial and temporal variation of phytoplankton community and its relationship with environmental parameters. Bi-monthly sampling campaigns were carried out at six fixed sites between 2012 and 2013. Physical-chemical and biological parameters were collected (chlorophyll a, phytoplankton composition and abundance) to perform the statistical correlations. The results indicate that phytoplankton community is mostly represented by diatoms, with Skeletonema costatum being the dominant species responsible for bloom in April and June of 2012. The dominance of this species is related to the high silicate concentrations, pH and turbidity. Other blooms events as well as the Euglena gracilis and Chlamydomonas sp. were recorded in February 2013, when the total phosphorus concentrations were high and the dissolved oxygen concentrations were higher. Dinoflagellates, cyanobacteria and diatom Thallassiosira sp. were widely distributed in the dry period and highly correlated with salinity, water transparency and nutrients. Hence, the distribution of phytoplankton community is more defined seasonally, rather than spatially.
DOI: 10.6084/m9.figshare.5667145.v1
title: Spatial and seasonal variation of microphytoplankton community and the correlation with environmental parameters in a hypereutrophic tropical estuary - Maranhão - Brazil

description: Abstract The Bacanga River Estuary has a hydrodynamic behavior and its tidal flow is limited by a dam. It is considered as a hypertrophic environment that receives daily high loads of domestic sewage without treatment. This study aimed to evaluate the spatial and temporal variation of phytoplankton community and its relationship with environmental parameters. Bi-monthly sampling campaigns were carried out at six fixed sites between 2012 and 2013. Physical-chemical and biological parameters were collected (chlorophyll a, phytoplankton composition and abundance) to perform the statistical correlations. The results indicate that phytoplankton community is mostly represented by diatoms, with Skeletonema costatum being the dominant species responsible for bloom in April and June of 2012. The dominance of this species is related to the high silicate concentrations, pH and turbidity. Other blooms events as well as the Euglena gracilis and Chlamydomonas sp. were recorded in February 2013, when the total phosphorus concentrations were high and the dissolved oxygen concentrations were higher. Dinoflagellates, cyanobacteria and diatom Thallassiosira sp. were widely distributed in the dry period and highly correlated with salinity, water transparency and nutrients. Hence, the distribution of phytoplankton community is more defined seasonally, rather than spatially.
DOI: 10.6084/m9.figshare.5667502
title: High bacterial carbon demand and low growth efficiency at a tropical hypereutrophic estuary: importance of dissolved organic matter remineralization

description: Abstract Simultaneous measurements of bacterioplankton production (BP) and respiration (BR) are imperative to understand the magnitude of carbon cycle in the lower trophic levels of the aquatic systems, but are still scarce in the tropics. The present study was performed in a highly productive estuary (Recife harbor, 08°03'S; 34°52'W, NE Brazil) where bacterial carbon demand (BCD=BP+BR) and growth efficiency (BGE=BP/BCD) were evaluated in order to estimate the major role of bacterioplankton: source or sink of organic carbon. In spite of the high BP rates (0.03-0.4 µMC h-1), the extremely high BR rates (0.5-4.1 µMC h-1) led to low BGE (0.02-0.29), possibly due to the high temperatures (&gt;25ºC) and strong inorganic nitrogen limitation (N:P ratios) The high BCD and low BGE indicate the major role of bacterioplankton as dissolved organic matter remineralizers, fueling the primary productivity of the system. These findings contradict what could be expected from studies in highly productive temperate estuaries (where BGE is usually &gt; 0.30) and highlight the importance of increasing in situ BP and BR estimates in tropical estuarine systems in order to better understand the role of these systems in global carbon cycling.
DOI: 10.6084/m9.figshare.5667502.v1
title: High bacterial carbon demand and low growth efficiency at a tropical hypereutrophic estuary: importance of dissolved organic matter remineralization

description: Abstract Simultaneous measurements of bacterioplankton production (BP) and respiration (BR) are imperative to understand the magnitude of carbon cycle in the lower trophic levels of the aquatic systems, but are still scarce in the tropics. The present study was performed in a highly productive estuary (Recife harbor, 08°03'S; 34°52'W, NE Brazil) where bacterial carbon demand (BCD=BP+BR) and growth efficiency (BGE=BP/BCD) were evaluated in order to estimate the major role of bacterioplankton: source or sink of organic carbon. In spite of the high BP rates (0.03-0.4 µMC h-1), the extremely high BR rates (0.5-4.1 µMC h-1) led to low BGE (0.02-0.29), possibly due to the high temperatures (&gt;25ºC) and strong inorganic nitrogen limitation (N:P ratios) The high BCD and low BGE indicate the major role of bacterioplankton as dissolved organic matter remineralizers, fueling the primary productivity of the system. These findings contradict what could be expected from studies in highly productive temperate estuaries (where BGE is usually &gt; 0.30) and highlight the importance of increasing in situ BP and BR estimates in tropical estuarine systems in order to better understand the role of these systems in global carbon cycling.
DOI: 10.6084/m9.figshare.5666947
title: Investigation of phagotrophy in natural assemblages of the benthic dinoflagellates Ostreopsis, Prorocentrum and Coolia

description: Abstract Mixotrophy has been shown to be a common trait among dinoflagellates and its importance in the nutritional ecology of harmful algae has been hypothesized. Benthic harmful species have not been extensively investigated as their planktonic counterparts and there are major gaps in the knowledge of their nutritional strategies. In this study the occurrence of phagotrophy was investigated in natural assemblages of benthic dinoflagellates using epi-fluorescence microscopy with DAPI and LysoSensor staining. The study was conducted at five sites along the coast of Rio de Janeiro that were visited in January, August and December 2010. In total, 1659 dinoflagellate cells were observed. From these, only 0.4% of 1195 Ostreopsis cf. ovata and 2.2% of 134 Coolia spp. cells presented evidence of phagotrophy with vacuoles stained by LysoSensor or a DAPI (4',6-diamidino-2-phenylindole) stained inclusion. Stained vacuoles were not registered in the 330 Prorocentrum spp. cells observed. Few O. cf. ovata cells contained round red inclusions ("red spots") that were not stained either by DAPI or LysoSensor, suggesting that these structures are not ingested prey. The results showed that phagotrophy was not a frequent nutritional strategy in benthic dinoflagellates during the study period.
DOI: 10.6084/m9.figshare.5666947.v1
title: Investigation of phagotrophy in natural assemblages of the benthic dinoflagellates Ostreopsis, Prorocentrum and Coolia

description: Abstract Mixotrophy has been shown to be a common trait among dinoflagellates and its importance in the nutritional ecology of harmful algae has been hypothesized. Benthic harmful species have not been extensively investigated as their planktonic counterparts and there are major gaps in the knowledge of their nutritional strategies. In this study the occurrence of phagotrophy was investigated in natural assemblages of benthic dinoflagellates using epi-fluorescence microscopy with DAPI and LysoSensor staining. The study was conducted at five sites along the coast of Rio de Janeiro that were visited in January, August and December 2010. In total, 1659 dinoflagellate cells were observed. From these, only 0.4% of 1195 Ostreopsis cf. ovata and 2.2% of 134 Coolia spp. cells presented evidence of phagotrophy with vacuoles stained by LysoSensor or a DAPI (4',6-diamidino-2-phenylindole) stained inclusion. Stained vacuoles were not registered in the 330 Prorocentrum spp. cells observed. Few O. cf. ovata cells contained round red inclusions ("red spots") that were not stained either by DAPI or LysoSensor, suggesting that these structures are not ingested prey. The results showed that phagotrophy was not a frequent nutritional strategy in benthic dinoflagellates during the study period.
DOI: 10.6084/m9.figshare.5667619
title: Plankton and water quality variability in an estuary before and after the shrimp farming effluents: possible impacts and regeneration

description: Abstract Water quality, chlorophyll a, phytoplankton, proto and mezo-zooplankton abundance were spatiotemporally evaluated in an estuary receiving effluents from a Pacific white shrimp Litopenaeus vannamei farm in Patos Lagoon estuary, Southern Brazil. Samples were taken before (BD) and; 1 day (1 PD) 5 days (5 PD), 10 days (10 PD), 20 days (20 PD) and 30 days (30 PD) after the effluents discharge. Some water quality parameters were affected by the effluents discharge; however, these changes were restricted to a distance of 20 m from the effluent discharge channel for a period of 5 days. The microbial community was dominated by chlorophyceae, followed by diatoms, cyanobacteria and ciliates. There was an increase in the abundance of different groups on the 1 PD sampling compared to BD. The zooplankton abundance was low in practically all sites, except for 30 PD sampling. The meso-zooplanktonic organisms were represented by copepods, mostly Acartia tonsa. Despite some effects on water quality and phytoplankton and protozooplankton abundance until 5 PD sampling, these alterations dissipated in a short period of time. We conclude that the environment quickly assimilated the effluents discharge, and the water quality parameters remained within the limits stipulated by standard guidelines.
DOI: 10.6084/m9.figshare.5667619.v1
title: Plankton and water quality variability in an estuary before and after the shrimp farming effluents: possible impacts and regeneration

description: Abstract Water quality, chlorophyll a, phytoplankton, proto and mezo-zooplankton abundance were spatiotemporally evaluated in an estuary receiving effluents from a Pacific white shrimp Litopenaeus vannamei farm in Patos Lagoon estuary, Southern Brazil. Samples were taken before (BD) and; 1 day (1 PD) 5 days (5 PD), 10 days (10 PD), 20 days (20 PD) and 30 days (30 PD) after the effluents discharge. Some water quality parameters were affected by the effluents discharge; however, these changes were restricted to a distance of 20 m from the effluent discharge channel for a period of 5 days. The microbial community was dominated by chlorophyceae, followed by diatoms, cyanobacteria and ciliates. There was an increase in the abundance of different groups on the 1 PD sampling compared to BD. The zooplankton abundance was low in practically all sites, except for 30 PD sampling. The meso-zooplanktonic organisms were represented by copepods, mostly Acartia tonsa. Despite some effects on water quality and phytoplankton and protozooplankton abundance until 5 PD sampling, these alterations dissipated in a short period of time. We conclude that the environment quickly assimilated the effluents discharge, and the water quality parameters remained within the limits stipulated by standard guidelines.
DOI: 10.6084/m9.figshare.14325707.v1
title: Assessing legacy contaminants in sediments from marine protected areas of the central coast of São Paulo (Brazil)

description: Abstract The presence of legacy contaminants in sediments from three Marine Protected Areas (MPAs) of the coast of São Paulo State was evaluated. Four sampling surveys were conducted between 2013 and 2015 in 10 sites, distributed along the Laje de Santos Marine and Xixova-Japui State Parks (PEMLS and XJSP, respectively) and Central Coast Marine Protection Area (APAMLC). Samples were analyzed for sediment texture, total organic carbon, CaCO3, metals (Al, Fe, Hg, Cd, Co, Cr, Cu, Ni, Pb and Zn), aliphatic and polycyclic aromatic hydrocarbons (AH and PAH). Sediments were generally sandy (excepting muddy samples from APAMLC), with variable amounts of TOC, OM and CaCO3. Most of the sediments exhibited low to moderate concentrations of metals, except APAMLC. Low contamination of sediments by hydrocarbons was found but samples from XLSP and APAMLC exhibited the highest concentrations of biogenic AH and PAH from pyrogenic sources. In APAMLC and PEMLS, the levels of metals can be considered as background levels according to geochemical indices (Igeo and EF). In XJSP and especially in APAMLC data indicated poor sediment quality, probably due to the effect of anthropic activities.
DOI: 10.6084/m9.figshare.14325707
title: Assessing legacy contaminants in sediments from marine protected areas of the central coast of São Paulo (Brazil)

description: Abstract The presence of legacy contaminants in sediments from three Marine Protected Areas (MPAs) of the coast of São Paulo State was evaluated. Four sampling surveys were conducted between 2013 and 2015 in 10 sites, distributed along the Laje de Santos Marine and Xixova-Japui State Parks (PEMLS and XJSP, respectively) and Central Coast Marine Protection Area (APAMLC). Samples were analyzed for sediment texture, total organic carbon, CaCO3, metals (Al, Fe, Hg, Cd, Co, Cr, Cu, Ni, Pb and Zn), aliphatic and polycyclic aromatic hydrocarbons (AH and PAH). Sediments were generally sandy (excepting muddy samples from APAMLC), with variable amounts of TOC, OM and CaCO3. Most of the sediments exhibited low to moderate concentrations of metals, except APAMLC. Low contamination of sediments by hydrocarbons was found but samples from XLSP and APAMLC exhibited the highest concentrations of biogenic AH and PAH from pyrogenic sources. In APAMLC and PEMLS, the levels of metals can be considered as background levels according to geochemical indices (Igeo and EF). In XJSP and especially in APAMLC data indicated poor sediment quality, probably due to the effect of anthropic activities.
DOI: 10.6084/m9.figshare.14325708
title: Assessing the sediment quality of the Laje de Santos marine state park and other marine protected areas of the central coast of São Paulo (Brazil)

description: Abstract In this study, the quality of sediments from three Marine Protected Areas (MPAs) located on the coast of São Paulo (Laje de Santos Marine State Park - PEMLS; Xixova-Japui State Park - XJSP; and Central Coast Marine Protection Area - APAMLC) was assessed. Four sampling surveys were conducted (September/October 2013; January 2014; July 2014; January 2015). Sediment samples were collected at10 sites, distributed along the 3 MPAs. Samples were analyzed for sediment texture, total organic carbon, CaCO3, metals, aliphatic and polycyclic aromatic hydrocarbons, and for whole-sediment and sediment-water interface toxicities. Principal component analysis (PCA) was used to integrate data. Most of the sediments exhibited low concentrations of chemicals, with the exception of those from P2 (APAMLC) where moderate levels of contaminants were detected. Sediments from P7 and P9 (PEMLS) occasionally showed signs of petroleum hydrocarbons. The other sediments showed no relevant contamination but presented variable toxicity, especially those of bioclastic composition. The PCA indicated a contribution of the sediment properties to the toxicities, especially the CaCO3. In bioclastic sediments, toxicity might be due to physical causes by or any indirect factor such as the presence of ammonia. It was concluded that both natural and anthropic factors are causing toxicity in sediments from the MPAs studied.
DOI: 10.6084/m9.figshare.14325708.v1
title: Assessing the sediment quality of the Laje de Santos marine state park and other marine protected areas of the central coast of São Paulo (Brazil)

description: Abstract In this study, the quality of sediments from three Marine Protected Areas (MPAs) located on the coast of São Paulo (Laje de Santos Marine State Park - PEMLS; Xixova-Japui State Park - XJSP; and Central Coast Marine Protection Area - APAMLC) was assessed. Four sampling surveys were conducted (September/October 2013; January 2014; July 2014; January 2015). Sediment samples were collected at10 sites, distributed along the 3 MPAs. Samples were analyzed for sediment texture, total organic carbon, CaCO3, metals, aliphatic and polycyclic aromatic hydrocarbons, and for whole-sediment and sediment-water interface toxicities. Principal component analysis (PCA) was used to integrate data. Most of the sediments exhibited low concentrations of chemicals, with the exception of those from P2 (APAMLC) where moderate levels of contaminants were detected. Sediments from P7 and P9 (PEMLS) occasionally showed signs of petroleum hydrocarbons. The other sediments showed no relevant contamination but presented variable toxicity, especially those of bioclastic composition. The PCA indicated a contribution of the sediment properties to the toxicities, especially the CaCO3. In bioclastic sediments, toxicity might be due to physical causes by or any indirect factor such as the presence of ammonia. It was concluded that both natural and anthropic factors are causing toxicity in sediments from the MPAs studied.
DOI: 10.6084/m9.figshare.14325711
title: Plankton in waters adjacent to the Laje de Santos state marine conservation park, Brazil: spatio-temporal distribution surveys

description: Abstract The coastal marine plankton plays a major role in ecosystem functioning by linking pelagic and benthonic environments through energy fluxes. Understanding the dynamic of planktonic organisms is also crucial for conservation and management purposes. Plankton was sampled at ten sites in the waters of the PEMLS and the adjacent area, on four different occasions through 2013 and 2015 in order to identify key planktonic groups and protocols for long-term monitoring. Ninety taxa of zooplanktonic organisms were found with holoplanktonic copepods and cladocerans dominating samples. Zooplankton biomass, mortality and taxonomic composition varied both in space and time. Surface chlorophyll-a concentrations varied spatio-temporally. A protocol for monitoring the plankton of the waters in and adjacent to the PEMLS is suggested based on biomass and mortality of zooplankton and biomass of phytoplankton using periodically in situ calibrated ocean color satellite imagery.
DOI: 10.6084/m9.figshare.14325711.v1
title: Plankton in waters adjacent to the Laje de Santos state marine conservation park, Brazil: spatio-temporal distribution surveys

description: Abstract The coastal marine plankton plays a major role in ecosystem functioning by linking pelagic and benthonic environments through energy fluxes. Understanding the dynamic of planktonic organisms is also crucial for conservation and management purposes. Plankton was sampled at ten sites in the waters of the PEMLS and the adjacent area, on four different occasions through 2013 and 2015 in order to identify key planktonic groups and protocols for long-term monitoring. Ninety taxa of zooplanktonic organisms were found with holoplanktonic copepods and cladocerans dominating samples. Zooplankton biomass, mortality and taxonomic composition varied both in space and time. Surface chlorophyll-a concentrations varied spatio-temporally. A protocol for monitoring the plankton of the waters in and adjacent to the PEMLS is suggested based on biomass and mortality of zooplankton and biomass of phytoplankton using periodically in situ calibrated ocean color satellite imagery.
DOI: 10.6084/m9.figshare.14325713
title: A preliminary analysis of the distribution and spatial/temporal patterns of seabirds in the Laje de Santos Marine State Park (Santos, Brazil) and surrounding waters

description: Abstract This study investigates the temporal taxonomic variation of the seabird community, and the spatial distributions of seabirds in the Laje de Santos Marine State Park (PEMLS) and surrounding waters, based on shipboard surveys. The increase in the number of seabird taxa during winter is associated to the presence of migratory birds from the south. During summer, only resident species were observed within the park. Analysis of the spatial distributions of taxa using geographic information systems (GIS) identified three different regions within the study area. The first was close to the coast, where birds interact with fishing activities in search for food; the second was the nesting area that provides shelter for the breeding colonies; and the third, which is farther offshore and more exposed, where a higher number of migratory birds were observed during winter surveys. The PEMLS and surrounding waters have characteristics that are important for the study and preservation of seabirds in Brazil and for the South Atlantic Ocean.