Manuel de Jesus Flores Montes

Chlorophyll a and nutrient distribution around seamounts and islands of the tropical south-western Atlantic

Data collected on two large-scale surveys around the seamounts and islands off north-eastern Brazil during 1997 and 1998 provided information on the distribution of Chlorophyll a and inorganic nutrients. During both surveys, the concentrations of Chlorophyll a and nutrients were highly patchy. The highest measurement of Chlorophyll a was 3.91 µg L–1 during 1997. A wide range of nutrient concentrations were found, from undetectable values to a maximum of 17.52 µm L–1 (Si), 1.37 µm L–1 (PO4), 10.02 µm L–1 (NO3) and 0.72 µm L–1 (NO2). In 1998, concentrations of Chlorophyll a and nutrients (nitrite and nitrate) were far more uniform, with Chlorophyll a concentrations lower and phosphate concentrations generally higher than in 1997. Topography–flow interaction on thermohaline structures was observed around Saint Peter and Saint Paul Archipelago and in the Fernando de Noronha Chain, creating a patchy pattern around the island and seamounts. Nutrients exhibited an inverse linear relationship with temperature and salinity and an exponential decay relationship with Chlorophyll a.

N:Si:P atomic ratio in the Santa Cruz Channel, Itamaracá-PE (Northeast Brazil): a nyctemeral variation

Estudos nas Barras Orange e Catuama do Canal de Santa Cruz, Itamaraca-PE, foram realizados durante os periodos chuvoso e seco, num ciclo nictemeral, com intervalo de 3 horas entre as coletas, numa seccao transversal. O objetivo foi a determinacao da variacao espacial e temporal da relacao N:Si:P, suas possiveis inter-relacoes e dependencias, bem como a influencia das condicoes hidrodinamicas locais, influenciadas pela variacao das mares em diferentes periodos do ano. Nitrito-N e nitrato-N, foram mais elevados no periodo chuvoso, enquanto que amonia-N, fosfato-P e silicato-Si, foram no periodo seco, sendo este resultado diferente de pesquisas anteriores. A relacao N:P foi menor que 16:1, nos diferentes periodos e estacoes, sendo porem, mais elevada no periodo chuvoso e na barra Orange, enquanto que a relacao Si:P esteve sempre superior a 15:1. Neste estudo, o nitrogenio foi o nutriente limitante para o fitoplâncton nesta area. Durante os ciclos nictemerais observados, os principais fatores que influenciaram a composicao dos parâmetros fisicos, quimicos e biologicos foi o ciclo de mares e parâmetros meteorologicos.

Impact of predicted climate change scenarios on a coral reef meiofauna community

&NA; Changes in marine communities in response to elevated CO2 have been reported but information on how representatives of the benthic lower trophic levels will be impacted remains scarce. A laboratory experiment was conducted to evaluate the impact of different climate change scenarios on a coral reef meiofauna community. Samples of the meiofauna community were collected from the coral reef subtidal zone of Serrambi beach (Ipojuca, Pernambuco, Brazil), using artificial substrate units. The units were exposed to control treatments and to three climate change scenarios, and collected after 15 and 29 d. Important changes in the meiofauna community structure were observed after 15 d of exposure. The major meiofauna groups exhibited divergent responses to the various scenarios. Although polychaetes were negatively affected after 29 d in the most severe scenario (Scenario III), harpacticoid copepods were negatively affected in Scenarios II and III after 15 and 29 d. Harpacticoid nauplii were strongly and negatively affected in all scenarios. In contrast, Nematoda exhibited higher densities in all scenarios. To the best of our knowledge, this community‐based study was the first to observe how meiofauna organisms from a coral reef environment react to the synergetic effects of reductions in seawater pH and increased temperature.

Spatial-Temporal Variability of the Thermohaline Properties in the Coastal Region of Fernando de Noronha Archipelago, Brazil

ABSTRACT Assunção, R.V.; Silva, A.C.; Martins, J., and Flores Montes, M., 2016. Spatial-Temporal variability of the thermohaline properties in the coastal region of Fernando de Noronha Archipelago, Brazil. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and Mc Carroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 512–516. Coconut Creek (Florida), ISSN 0749-0208. Brazilian oceanic islands are areas of great environmental, scientific, economic and strategic interest for the country. A better understanding of the thermohaline and hydrodynamic properties is fundamental to complement studies of chemical and biological processes active on the Fernando de Noronha archipelago, located between 03° 52′S and 32° 25′W. The aim of this work was to verify the coastal thermohaline behavior of the most inhabited part of the island, on a seasonal and spatial scale and how it is associated with the nutrient distribution data. Four campaigns were conducted in 2013 and 2014, two during the wet season and two during the dry season. For each period, data were collect at five stations. The results show that during the rainy season temperature increases and salinity decreases in the surface layer. Spatially no large differences are observed. Regarding to nutrient concentration, seasonal concentrations are quite homogeneous in the waters of the archipelago region. The coastal region was characterized by tropical mass water.

The instantaneous transport of inorganic and organic material in a highly polluted tropical estuary

The contribution of the estuarine channel of Recife harbour to the eutrophication of the Recife coastal area was evaluated by quantifying the instantaneous transport of salt, dissolved inorganic nutrients (PO4–, SiOH4, NO3–, NO2– and, NH4+), material in suspension, Chlorophyll-a, pico–nanoplankton and microplankton during the rainy (June 2007) and dry (November 2007) seasons. The results showed that all of the dissolved nitrogenated nutrients, the silicate and the material in suspension had higher concentrations during the rainy season, whereas the phosphate and Chlorophyll-a (both the total and the pico–nanoplankton and microplankton fractions) showed greater concentrations during the dry season. All of the materials considered were exported to the sea except for Chlorophyll-a (pico–nanoplankton and microplankton fractions) during the dry season, when these materials were imported into the area. The total liquid transport in the rainy season was three times higher than that found for the dry season. Silicate represented nearly 85% of the total exported material during the rainy period, whereas during the dry season, phosphate and silicate represented 79% of the total exported material. The stratification and circulation processes indicated a well mixed environment. The water-renewal rate was low, as demonstrated by the input of phytoplankton biomass during November. The area was characterised as eutrophic during the months investigated.

The Influence of Urban Effluents on the Elemental C/N Ratio in a Tropical Coastal Area of Northeastern Brazil

ABSTRACT Travassos, R.K.; Flores Montes, M.J.; Costa, B.V. M., and Silva Junior, J.M., 2016. The influence of urban effluents on the elemental C/N ratio in a tropical coastal area of northeastern Brazil. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 168-172. Coconut Creek (Florida), ISSN 0749-0208. The present study was performed in a tropical and highly eutrophic estuarine system in the urban coastal area of Greater Recife, Pernambuco, northeastern Brazil. Organic carbon is introduced into these urban estuaries through domestic and industrial sewage waste. One indicator of anthropogenic influence is the concentration of organic matter, including the suspended elemental forms of carbon and total nitrogen and the C/N ratio. The distribution of the concentrations of both particulate organic carbon and total nitrogen (POC and TN, respectively) were studied in two parallel transects in the estuarine plumes of Pernambucos major rivers, the Capibaribe (CP) and the Jaboatão (JP), from 2010 to 2011. The archipelago of Fernando de Noronha, with relatively little human influence, was selected as the control area. The particulate organic matter exported via estuarine flow was defined by elemental carbon median values of 2.04% and 0.97%. The C/N ratio of the Capibaribe and Jaboatão plumes featured median values of 6.60 and 9.30, respectively. The principal components analysis (PCA) results suggest that the percentage of POC was influenced by rainfall and that the percentage of TN was influenced by the transport of suspended particulate matter. These differences may result from different loads of human activities and estuary transport dynamics, and the coastal region highlights the complexity of the distribution of organic matter in these environments.

Quantification and classification of the main environmental impacts on a Halodule wrightii seagrass meadow on a tropical island in northeastern Brazil

Multiple stress mechanisms have caused a worldwide decrease in seagrasses, which are vulnerable to environmental and/or anthropogenic pressure. The loss of seagrass meadows of Halodule wrightii is reported for the littoral of Itamaracá Island (Northeastern Brazil). The present study identified the main anthropogenic factors that negatively influenced over the abundance and distribution of seagrass meadows between July and September 2007 at the Jaguaribe and Pilar Beaches, Eastern littoral of Itamaracá. Anthropogenic impact included the discharge of untreated sewage through fluvial channels, urban and commercial development along the coast, the anchoring of motorized and non-motorized boats, diverse fishing techniques and the dumping of solid waste. The data indicates that the Pilar is an environment with a higher impact index (71.43%) when compared with the Jaguaribe (57.14%), standing out the number of boats with a central motor, the total number of boats, the presence of shellfish gatherers and coastal urban development. The present study reinforces the need for defining management and conservation measures for this ecosystem, which has high ecological and economic value.

New records of the larval forms Cerataspis monstrosa and Amphionides reynaudii (Crustacea: Decapoda) from the western tropical Atlantic

The current biogeographic and taxonomic knowledge on decapod larvae in tropical oceans is still very incomplete, in spite of their huge ecological and socio-economic importance. The present study reports two new records for decapod larval forms in pelagic environments off oceanic islands in the western tropical Atlantic, and provides detailed diagnoses and images of these larvae. Samples were taken from July 2010 to November 2014 using neuston, bongo and WP-2 nets at three localities: St. Peter and St. Pauls Archipelago (SPSP), Rocas Atoll (RA) and Fernando de Noronha Archipelago (FN). The larval forms Cerataspis monstrosa (Gray, 1828) and Amphionides reynaudii (H. Milne Edwards, 1832) were recorded around these areas, constituting the first record for these oceanic islands. Out of 121 samples analyzed, one specimen of C. monstrosa (Mysis II) was found off FN, and 20 specimens of A. reynaudii in nine distinct stages (Mysis II, IV, VI, VII, VIII, IX, X, XI, XII) were found off SPSP, RA and FN.

Net Heterotrophy in the Amazon Continental Shelf Changes Rapidly to a Sink of CO2 in the Outer Amazon Plume

The Amazon continental shelf and adjacent oceanic area were sampled for inorganic and organic carbon parameters in order to improve data coverage and understanding of carbon cycling dynamics within this important region. Seasonal coverage of the Amazon plume on the French Guiana continental shelf further north, was provided by CO2 monitoring using a merchant ship sailing from France to French Guiana (2006-2016). Salinity ranged from 1 to 36 (transects in April 2013, and May 2014). At salinity below 10, strong outgassing was observed with fugacity of CO2 (fCO2) over 2000 atm. This region displayed net heterotrophy, fueled by organic matter with terrestrial origin, as shown by 13C and 15N values of suspended particles. A 13C cross shelf average of -31‰ was measured during May 2014, contrasting with oceanic values in excess of -20‰. The reactivity of this terrestrial material resulted in the local production of dissolved inorganic and organic carbon as well as fluorescent humic compounds. Further offshore, the dilution of freshwater by ocean waters created a sink for CO2, enhanced by biological activity. The strongest CO2 drawdowns, associated with high chlorophyll a concentrations, were observed on the French Guiana continental shelf in the outer Amazon plume, with fCO2 values below 150 uatm. Here, a CO2 sink was present almost throughout the year, with a seasonal maximum of -9.2 mmol CO2 m-2d-1 observed in June 2015. However, both the CO2 and salinity distributions could vary significantly within a few days, confirming the presence of many eddies in this region. The Amazon continental shelf hence behaved as a transition zone between an inshore source of CO2 to the atmosphere and an offshore sink. Some marine phytoplankton production was detected but occurred mainly close to the French Guiana shelf. A mean net CO2 outgassing of 44 ± 43.6 mmol m-2d-1 was estimated for the area. Quantifying the CO2 flux for the entire Amazon shelf area led to a revised annual estimate of the net ocean carbon export of 2.86 1012 mol C from the region.

Caracterización de los flujos de CO2 y los parámetros asociados con el sistema de carbonato en el estuario Río Formoso, Brasil

Nine surface water surveys were performed in the Formoso estuary (Brazil) during 2012-2013 mainly in summer and winter periods and during spring tide. Temporal variations of temperature, salinity, phosphate, silicate, total alkalinity, dissolved inorganic carbon, partial pressure of CO2 (pCO2) and water-air CO2 fluxes were analyzed. Low rates of water-air CO2 fluxes (4.7 ± 8.0 mmol C m-2 d-1) were estimated despite the different climate conditions. pCO2 values ranged from 190 to 988 matm. These values are lower than those observed in other tropical estuaries. CO2 fluxes presented in this study contribute to the characterization of humid tropical estuarine systems, thus filling an important geographical information gap.