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

2013 ◽  
Vol 64 (2) ◽  
pp. 168 ◽  
Author(s):  
Christiane Sampaio de Souza ◽  
Joana Angélica Guimarães da Luz ◽  
Silvio Macedo ◽  
Manuel de Jesus Flores Montes ◽  
Paulo Mafalda
Keyword(s):  
Chlorophyll A ◽  
Large Scale ◽  
Saint Paul ◽  
Nutrient Concentrations ◽  
Nutrient Distribution ◽  
Western Atlantic ◽  
Eastern Brazil ◽  
Wide Range ◽  
North Eastern ◽  
Fernando De Noronha

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.

Taxonomy of Plakortis and Plakinastrella (Demospongiae: Plakinidae) from oceanic islands off north-eastern Brazil, with description of three new species

2003 ◽  
Vol 83 (2) ◽  
pp. 385-397 ◽  
Author(s):  
Fernando C. Moraes ◽  
Guilherme Muricy
Keyword(s):  
New Species ◽  
Morphological Characters ◽  
Oceanic Islands ◽  
Western Atlantic ◽  
Eastern Brazil ◽  
North Eastern ◽  
Fernando De Noronha ◽  
Plakortis Angulospiculatus ◽  
Three New Species ◽  
Shape And Size

Three species of Plakortis and one of Plakinastrella (Demospongiae: Homosclerophorida) collected mostly at oceanic islands off north-eastern Brazil (Atol das Rocas, Fernando de Noronha and São Pedro e São Paulo Archipelago) are described, three of which are new to science: Plakortis angulospiculatus, P. insularis sp. nov., P. microrhabdifera sp. nov, and Plakinastrella microspiculifera sp. nov. External morphological characters such as colour, oscules, and consistency are sufficient to discriminate all the four species in the field, except Plakortis angulospiculatus from P. microrhabdifera. Internal features such as skeletal arrangement, shape and size of diods, and presence of microrhabds and calthrops are also important taxonomic characters for western Atlantic Plakortis and Plakinastrella. We consider as valid only five species of Plakortis in the western Atlantic: the three species described here plus P. halichondrioides and P. zyggompha. All these species except P. zyggompha have been recorded from Brazil. Plakinastrella has now two species in the western Atlantic, P. onkodes and P. microspiculifera sp. nov. The generic distinction between Plakortis and Plakinastrella is tenuous, based only on the presence of spicule size-classes and of deformed vs normal calthrops, and both genera need detailed revision.

A new species of Stoeba (Demospongiae: Astrophorida) from oceanic islands off north-eastern Brazil

2007 ◽  
Vol 87 (6) ◽  
pp. 1387-1393 ◽  
Author(s):  
Fernando Moraes ◽  
Guilherme Muricy
Keyword(s):  
New Species ◽  
First Record ◽  
Oceanic Islands ◽  
Sao Paulo ◽  
Valid Species ◽  
Western Atlantic ◽  
Eastern Brazil ◽  
North Eastern ◽  
Fernando De Noronha ◽  
A New Species

The genus Stoeba has 11 recognized species. Herein we describe a new species of Stoeba endemic from two oceanic archipelagoes off north-eastern Brazil (Fernando de Noronha and São Pedro e São Paulo), constituting the first record of this genus for the western Atlantic. Stoeba latex sp. nov. is characterized by its thickly encrusting to massive shape, stretched surface, brownish-red colour, and spiculation of calthrops and sanidasters with well developed spines; dichotriaenes and oxeas are absent. Stoeba and Dercitus are very closely related genera, and should probably be merged. The genus Stoeba now contains the following valid species: S. dissimilis, S. exostotica, S. extensa, S. lesinensis, S. natalensis, S. occulta, S. pauper, S. plicata, S. reptans, S. simplex, S. syrmatita and S. latex sp. nov. Several other species still await description. A key to the valid species of Stoeba is given.

Taxonomy of Nystiellidae (Caenogastropoda, Epitonioidea) from Brazil, with description of three new species from the South-western Atlantic

2017 ◽  
Vol 98 (7) ◽  
pp. 1619-1644 ◽  
Author(s):  
Alexandre Dias Pimenta ◽  
Bruno Garcia Andrade ◽  
Ricardo Silva Absalão
Keyword(s):  
Rio Grande ◽  
Taxonomic Revision ◽  
South Atlantic ◽  
Shell Morphology ◽  
The South ◽  
Western Atlantic ◽  
North East ◽  
The North ◽  
Eastern Brazil ◽  
North Eastern

A taxonomic revision of the Nystiellidae from Brazil, including samples from the Rio Grande Rise, South Atlantic, was performed based on shell morphology. Five genera and 17 species were recognized. For the richest genus,Eccliseogyra, the three species previously recorded from Brazil were revised:E. brasiliensisandE. maracatu, previously known only from their respective type series, were re-examined. Newly available material ofE. maracatuexpanded the known geographic range of this species to off south-east Brazil.Eccliseogyra nitidais now recorded from north-eastern to south-eastern Brazil, as well as from the Rio Grande Rise. Three species ofEccliseogyraare newly recorded from the South Atlantic:E. monnioti, previously known from the north-eastern Atlantic, occurs off eastern Brazil and on the Rio Grande Rise; its protoconch is described for the first time, confirming its family allocation.Eccliseogyra pyrrhiasoccurs off eastern Brazil and on the Rio Grande Rise, andE. folinioff eastern Brazil. The genusIphitusis newly recorded from the South Atlantic.Iphitus robertsiwas found off northern Brazil, although the shells show some differences from the type material, with less-pronounced spiral keels. Additional new finds showed thatIphitus cancellatusranges from eastern Brazil to the Rio Grande Rise, and Iphitusnotiossp. nov. is restricted to the Rio Grande Rise.Narrimania, previously recorded from Brazil based on dubious records, is confirmed, including the only two living species described for the genus:N. azelotes, previously only known from the type locality in Florida, andN. concinna, previously known from the Mediterranean. A third species,Narrimania raquelaesp. nov. is described from eastern Brazil, diagnosed by its numerous and thinner cancellate sculpture. To the three species ofOpaliopsispreviously known from Brazil, a fourth species,O. arnaldoisp. nov., is added from eastern Brazil, and diagnosed by its very thin spiral sculpture, absence of a varix, and thinner microscopic parallel axial striae.Papuliscala nordestina, originally described from north-east Brazil, is recorded off eastern Brazil and synonymized withP. elongata, a species previously known only from the North Atlantic.

Nutrient distribution in the Bosphorus and surrounding areas

2002 ◽  
Vol 46 (8) ◽  
pp. 59-66 ◽  
Author(s):  
E. Okuş ◽  
A. Aslan-Yilmaz ◽  
A. Yüksek ◽  
S. Taş ◽  
V. Tüfekçi
Keyword(s):  
Chlorophyll A ◽  
Black Sea ◽  
Nutrient Dynamics ◽  
Lower Layer ◽  
Water Quality Monitoring ◽  
Nutrient Concentrations ◽  
The Black Sea ◽  
Sea Of Marmara ◽  
Nutrient Distribution ◽  
Northwestern Shelf

As part of a five years monitoring project “Water Quality Monitoring of the Strait of Istanbul”, February-December 1999 nutrient dynamics of the Black Sea-the Sea of Marmara transect are studied to evaluate the effect of discharges given by deep disposals. Through a one-year study, upper layer nutrient concentrations were generally under the effect of northwestern-shelf Black Sea originated waters. This effect was strictly observed in July, when the upper layer flow was the thickest. On the other hand, partly in November but especially in December the northwestern-shelf Black Sea originated water flow was a minimum resulting in similar concentrations in both layers. Nutrient fluctuations also affected the chlorophyll a and POC concentrations as parameters of productivity. The nutrient concentrations decreased with the effect of spring bloom and highest chlorophyll a values were detected in November at Strait stations that did not match to the Sea of Marmara values. This fact represents the time-scale difference between the Black Sea and the Sea of Marmara. On the contrary, high nutrient concentrations in the lower layer (especially inorganic phosphate), and therefore low N:P ratios reflect the effect of deep discharge. Vertical mixing caused by meteorological conditions of the shallow station (M3) under the effect of surface discharges resulted in homogenous distribution of nutrients. Nutrient concentrations of the stations affected by deep discharge showed that the two-layer stratification of the system did not permit the discharge mix to the upper layer.

Two new shallow-water species ofHaliclonafrom north-eastern Brazil (Demospongiae: Haplosclerida: Chalinidae)

2014 ◽  
Vol 96 (2) ◽  
pp. 237-249 ◽  
Author(s):  
André Bispo ◽  
Monica Dorigo Correia ◽  
Eduardo Hajdu
Keyword(s):  
Shallow Water ◽  
Ex Situ ◽  
Eastern Brazil ◽  
Wide Range ◽  
North Eastern ◽  
The World ◽  
Dark Green ◽  
Scientific Collections ◽  
Shallow Water Species ◽  
Water Species

Haliclonais an unusually species-rich genus in Porifera, with more than 400 species described. In spite of many subgenera used in the taxonomic housekeeping of these sponges, over half of them remain unassigned to a subgenus, thus encouraging a wide range of redescriptions and taxonomic revisions of materials from all around the world. In this paper, we describe two newHaliclonaspp. collected at Pernambuco, Alagoas and Bahia States (north-eastern Brazil, between 08°46′S and 13°56′S).Haliclona(Reniera)chlorillasp. nov. is a dark green or black coloured, delicately-branched species; andHaliclona(Soestella)peixinhoaesp. nov., a beige-coloured, tubular species, where tubes frequently bear large thorns and possess a conspicuous sub-superficial meandering reticulation. These species highlight the importance of includingex-situcollections in compiling baseline data, as both were already present in scientific collections by the 1980s and 1990s.

scholarly journals Whalesuckers and a spinner dolphin bonded for weeks: does host fidelity pay off?

2003 ◽  
Vol 3 (2) ◽  
pp. 1-5 ◽  
Author(s):  
José Martins Silva-Jr ◽  
Ivan Sazima
Keyword(s):  
First Record ◽  
Host Fidelity ◽  
Social Nature ◽  
Eastern Brazil ◽  
Individual Host ◽  
North Eastern ◽  
Fernando De Noronha ◽  
In The Wild ◽  
Spinner Dolphins ◽  
First Time

The whalesucker Remora australis (Echeneidae) is an oceanic diskfish found attached to cetaceans only and its habits are therefore poorly known. At the Fernando de Noronha Archipelago, off North-eastern Brazil, spinner dolphins Stenella longirostris (Delphinidae) regularly congregate in large groups in a shallow bay, which allows for underwater observations of their behaviour and their fish associates. In the course of a broader study of this elusive diskfish, we had the opportunity to made multiple records of two whalesucker couples (three of the fish naturally marked) attached to the same individual dolphin in two different years, over periods of 47 and 87 days respectively. In all the sightings the whalesucker individuals of a couple were recorded side-by-side and positioned on their host’s belly. We surmise that at least one of the couples was a reproductive pair, as the belly of the larger fish was noticeably swollen in the last sighting, and the bulge on its belly was bilateral and extended almost uniformly to the vent, a strong indication of fully mature gonads. Moreover, its size matched those of the mature females of this diskfish species. To our knowledge, this is the first time that attachment fidelity of the whalesucker to any cetacean host is documented in the wild. We hypothesize that attachment fidelity to the same individual host increases the whalesucker’s chance to mate, and suggest further that the highly social nature of the spinner dolphins facilitates encounters between potential mating partners. Our study indicates that host fidelity possibly is not an uncommon feature of the whalesucker behaviour, albeit difficult to recognise. In one of the above recorded whalesuckers the natural marking was a crescentic scar characteristic of the wounds inflicted by the cookiecutter Isistius brasiliensis (Dalatiidae), a first record of the attack of this shark to any diskfish species.

Development of cyanobacterial application methods for soil protection and restoration: case studies in Australian drylands

2020 ◽  
Author(s):  
Marco A. Jiménez-González ◽  
Jose Raul Roman ◽  
Yolanda Canton ◽  
Gonzalo Almendros ◽  
Angela M. Chilton ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Large Scale ◽  
Soil Stabilization ◽  
Weight Ratio ◽  
Soil Protection ◽  
Adaptation Period ◽  
Degraded Soil ◽  
North West ◽  
Wide Range ◽  
Direct Inoculation

<p>Land degradation, as a result of increased soil erosion and loss of fertility among other factors, is currently one of the most serious environmental problems. In recent years, the role of cyanobacteria from soil biocrusts in re-establishing soil function of degraded areas is gaining interest due to the potential of these organisms for soil stabilization and increase of soil fertility. In order to fully exploit the use of cyanobacteria in large-scale restoration of degraded lands, new approaches that facilitate their application must be explored in order to face with the harsh abiotic conditions of these environments. In this presentation, we showcase two different methods for the inoculation of cyanobacteria from soil biocrust in degraded soils of Australian dryland ecosystems: i) direct inoculation of cyanobacteria cultures and ii) incorporation of cyanobacteria within extruded pellets. Three soil native cyanobacterial strains from two representative N-fixing genera (Nostoc and Scytonema) and a non-heterocystous filamentous genus (Leptolyngbya) previously collected from the Pilbara region (north-west Western Australia), were used as inoculum. Then, in a multifactorial microcosm experiment under laboratory conditions, we evaluated the survival and establishment of the cyanobacteria for both methods. For the direct inoculation, cultures of isolated cyanobacteria and a mixture of them were applied as a liquid inoculum directly into a degraded soil from the Pilbara. In the case of application using extruded pellets, fresh cultures of each strain alone and an equal mixed of them were added into a substrate composed of commercial bentonite powder and sand (1:10 weight ratio). The composed solution was extruded through a jerky gun with an extruder nozzle into pellets (1 cm diameter x 2 cm length) and dried at 30<sup>o</sup>C for 24h. Pellets were then placed on the surface of three different degraded soils representative of Australian drylands: a mine waste from an active mine site in the Pilbara, a degraded soil from the Cobar Peneplain (New South Wales), and a soil from the Simpson Strzelecki Dunefields (South Australia). In both experiments, cyanobacteria growth and establishment were monitored. Our results showed that in both treatments cyanobacteria colonize almost the entire Petri dish surface in all treatments. Furthermore, the levels of chlorophyll a (a proxy for cyanobacterial biomass) remained constant on inoculated samples during the study period, suggesting that cyanobacteria survived the pelleting process. In the case of direct inoculation, a decrease of chlorophyll a was observed in the beginning but then it stabilized and started to increase at the final stage of the experiment. This process may be due to the adaptation period of the cyanobacteria in the new environment, which is most progressive in the case of pellets application. Overall, our results showed that cyanobacteria can be successfully applied as a liquid inoculum and incorporated into extruded pellets, quickly colonizing degraded soi substrates. These technologies are ready for further testing and refining through field trials, opening a wide range of opportunities to face with large scale restoration programs.</p>

The effect of the Fernando de Noronha plume on the mantle lithosphere in north-eastern Brazil

Lithos ◽  
2007 ◽  
Vol 94 (1-4) ◽  
pp. 111-131 ◽  
Author(s):  
Giorgio Rivalenti ◽  
Alberto Zanetti ◽  
Vicente A.V. Girardi ◽  
Maurizio Mazzucchelli ◽  
Colombo C.G. Tassinari ◽  
...  
Keyword(s):  
Mantle Lithosphere ◽  
Eastern Brazil ◽  
North Eastern ◽  
Fernando De Noronha

scholarly journals Inverse-model estimates of the ocean's coupled phosphorus, silicon, and iron cycles

2017 ◽  
Vol 14 (18) ◽  
pp. 4125-4159 ◽  
Author(s):  
Benoît Pasquier ◽  
Mark Holzer
Keyword(s):  
Steady State ◽  
Ocean Circulation ◽  
Large Scale ◽  
The Other ◽  
Global Ocean ◽  
Nutrient Concentrations ◽  
Iron Source ◽  
Fractional Contribution ◽  
Wide Range ◽  
Phosphorus Export

Abstract. The ocean's nutrient cycles are important for the carbon balance of the climate system and for shaping the ocean's distribution of dissolved elements. Dissolved iron (dFe) is a key limiting micronutrient, but iron scavenging is observationally poorly constrained, leading to large uncertainties in the external sources of iron and hence in the state of the marine iron cycle. Here we build a steady-state model of the ocean's coupled phosphorus, silicon, and iron cycles embedded in a data-assimilated steady-state global ocean circulation. The model includes the redissolution of scavenged iron, parameterization of subgrid topography, and small, large, and diatom phytoplankton functional classes. Phytoplankton concentrations are implicitly represented in the parameterization of biological nutrient utilization through an equilibrium logistic model. Our formulation thus has only three coupled nutrient tracers, the three-dimensional distributions of which are found using a Newton solver. The very efficient numerics allow us to use the model in inverse mode to objectively constrain many biogeochemical parameters by minimizing the mismatch between modeled and observed nutrient and phytoplankton concentrations. Iron source and sink parameters cannot jointly be optimized because of local compensation between regeneration, recycling, and scavenging. We therefore consider a family of possible state estimates corresponding to a wide range of external iron source strengths. All state estimates have a similar mismatch with the observed nutrient concentrations and very similar large-scale dFe distributions. However, the relative contributions of aeolian, sedimentary, and hydrothermal iron to the total dFe concentration differ widely depending on the sources. Both the magnitude and pattern of the phosphorus and opal exports are well constrained, with global values of 8. 1  ±  0. 3 Tmol P yr−1 (or, in carbon units, 10. 3  ±  0. 4 Pg C yr−1) and 171.   ±  3.  Tmol Si yr−1. We diagnose the phosphorus and opal exports supported by aeolian, sedimentary, and hydrothermal iron. The geographic patterns of the export supported by each iron type are well constrained across the family of state estimates. Sedimentary-iron-supported export is important in shelf and large-scale upwelling regions, while hydrothermal iron contributes to export mostly in the Southern Ocean. The fraction of the global export supported by a given iron type varies systematically with its fractional contribution to the total iron source. Aeolian iron is most efficient in supporting export in the sense that its fractional contribution to export exceeds its fractional contribution to the total source. Per source-injected molecule, aeolian iron supports 3. 1  ±  0. 8 times more phosphorus export and 2. 0  ±  0. 5 times more opal export than the other iron types. Conversely, per injected molecule, sedimentary and hydrothermal iron support 2. 3  ±  0. 6 and 4.   ±  2.  times less phosphorus export, and 1. 9  ±  0. 5 and 2.   ±  1.  times less opal export than the other iron types.

scholarly journals Taxonomic revision of the genus Hyperaulax Pilsbry, 1897 (Gastropoda, Stylommatophora, Odontostomidae)

2019 ◽  
Vol 95 (2) ◽  
pp. 453-463 ◽  
Author(s):  
Rodrigo Brincalepe Salvador ◽  
Daniel C. Cavallari
Keyword(s):  
Dna Sequences ◽  
Taxonomic Revision ◽  
Junior Synonym ◽  
Valid Species ◽  
Eastern Brazil ◽  
The Family ◽  
North Eastern ◽  
Fernando De Noronha ◽  
Living Species

The genus Hyperaulax Pilsbry, 1897 comprises two living species endemic to the oceanic Fernando de Noronha Archipelago, off north-eastern Brazil. They are currently allocated in two subgenera, Hyperaulax s. str. and Bonnanius Jousseaume, 1900, belonging to the family Odontostomidae. Herein we present a taxonomic revision of these species, assessing their familiar allocation within Orthalicoidea, offering updated diagnoses and descriptions, figuring the type materials and further relevant specimens, and providing barcoding DNA sequences. We conclude that Bonnanius is a junior synonym of Hyperaulax, which is classified in Odontostomidae. The genus contains two valid species, H. ridleyi and H. ramagei, both endemic to Fernando de Noronha.

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