Larval fish of the Campos Basin, southeastern Brazil

Studies on the vertical distribution of larval fish in water masses along the Brazilian coast are very rare. The present study aimed to identify larval fish occurring in the surface (1 m) layer and at depth in four water masses of the Campos Basin, southeastern Brazil: South Atlantic Central Water (SACW) (250 m), Antarctic Intermediate Water (AAIW) (800 m), Upper Circumpolar Deep Water (UCDW) (1,200 m) and North Atlantic Deep Water (NADW) (2,300 m). Material used in this study was obtained in 2009 through nocturnal horizontal stratified hauls using a Multinet (500 μm mesh size) during both rainy (February to April) and dry periods (August to September). A total of 10,978 fish larvae comprising 169 taxa were identified during the rainy (n = 6,015) and dry (n = 4,963) periods. The number of taxa decreased as the sampling depth increased. Larvae of Clupeidae, Engraulidae and Scombridae dominated in samples collected in the surface layer, while Sternoptychidae and Myctophidae were the most representative families in SACW. The other three water masses were dominated by Gonostomatidae larvae.

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Four new species of Polycirrus Grube, 1850 (Polychaeta: Terebellidae) from Campos Basin, southeastern Brazil

Zootaxa ◽

10.11646/zootaxa.3626.1.6 ◽

2013 ◽

Vol 3626 (1) ◽

pp. 146-172

Author(s):

ORLEMIR CARRERETTE ◽

JOÃO MIGUEL DE MATOS NOGUEIRA

Keyword(s):

New Species ◽

Rio De Janeiro ◽

Environmental Heterogeneity ◽

Southeastern Brazil ◽

Brazilian Coast ◽

Campos Basin

Four new species of Polycirrus were collected at the Campos Basin, state of Rio de Janeiro, during a survey coordinated by CENPES/PETROBRAS under the scope of the project, "Environmental Heterogeneity in the Campos Basin". These species are P. nonatoi sp. nov., P. papillosus sp. nov., P. breviuncinatus sp. nov., and P. habitats sp. nov. All these species are herein described and compared with the morphologically most similar congeners. In addition, a key is provided for the identification of the species of Polycirrus which have been originally described for the Brazilian coast.

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DISTRIBUCIÓN Y DENSIDAD DE ICTIOPLANCTON EN EL ESTUARIO DE BAHÍA MÁLAGA, PACÍFICO COLOMBIANO (SEPTIEMBRE DE 2009-FEBRERO DE 2010)

Bulletin of Marine and Coastal Research ◽

10.25268/bimc.invemar.2014.43.1.34 ◽

2016 ◽

Vol 43 (1) ◽

Author(s):

Diana Medina Contreras ◽

Jaime Cantera ◽

Eugenia Escarria ◽

Luz M Mejía Ladino

Keyword(s):

Fish Assemblages ◽

Larval Fish ◽

Fish Larvae ◽

Larval Density ◽

Temporal Distribution ◽

Mesh Size ◽

Temporal Variations ◽

Taxonomic Composition ◽

Total Density ◽

The Relationship

The density, taxonomic composition, and spatial and temporal distribution of the estuarine ichthyoplankton of Bahía Málaga (Pacific coast of Colombia) are described, as well as the relationship between biological parameters and some physicochemical variables. Samples were collected at 12 stations along the principal navigation canal; these samples were taken in four areas following the design of Barletta-Bergan. Surface sweeps were carried out with a conical-cylindrical net (mesh size 500 µm, mouth diameter 0.6 m, length 3.5 m). Salinity and temperature were measured before each sweep. A total of 69019 larvae/1000 m³, representing 23 families, 36 genera and 40 species were collected during monthly sampling from September, 2009 to February, 2010. Carangidae (39.0%) was the most abundant family, followed by Sciaenidae (27.1%) and Engraulidae (20.1%). The most frequent families were Sciaenidae (26.6%), followed by Carangidae (22.8%) and Engraulidae (14.7%) which are important families in larval fish assemblages in tropical estuaries. Eighty percent of total density was provided by six species, of which Seriola morphotype 1 (Carangidae) and Cetengraulis mysticetus (Engraulidae) were the most abundant and dominant. No correlation was found between density and salinity (Spearman, R = 0.23) or temperature (Spearman, R = 0.51). Analysis of spatial and temporal variations of larval density shows significant differences among the months sampled (Anova, p = 0.0029; p < 0.05), but not among areas (Anova, p = 0.078), suggesting that Bahía Málaga offers adequate conditions for the presence of fish larvae.

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Silicon pool dynamics and biogenic silica export in the Southern Ocean, inferred from Si-isotopes

Ocean Science Discussions ◽

10.5194/osd-8-639-2011 ◽

2011 ◽

Vol 8 (2) ◽

pp. 639-674 ◽

Cited By ~ 3

Author(s):

F. Fripiat ◽

A.-J. Cavagna ◽

F. Dehairs ◽

S. Speich ◽

L. André ◽

...

Keyword(s):

Southern Ocean ◽

Silicic Acid ◽

Mixed Layer ◽

Deep Water ◽

Biogenic Silica ◽

Water Masses ◽

Intermediate Water ◽

Subtropical Zone ◽

Isotopic Signatures ◽

The Antarctic

Abstract. Water column silicon isotopic signatures (δ30Si) of silicic acid (Si(OH)4) in the Southern Ocean were measured along a meridional transect from South Africa (Subtropical Zone) down to 57° S (northern Weddell Gyre). These data are the first reported for a summer transect across the whole Antarctic Circumpolar Current (ACC). δ30Si variations are large in the upper 1000 m, reflecting the effect of the silica pump superimposed upon meridional transfer across the ACC: the transport of Antarctic surface waters northward by a net Ekman drift and their convergence and mixing with warmer upper-ocean Si-depleted waters to the north. Using Si isotopic signatures, we determined different mixing interfaces between ACC water masses: the Antarctic Surface Water (AASW), the Antarctic Intermediate Water (AAIW), and the thermoclines in the low latitude areas. The residual silicic acid concentrations of end-members control the δ30Si alteration of the mixing products. With the exception of AASW, all mixing interfaces have a highly Si-depleted mixed layer end-member. These processes deplete the silicic acid AASW concentration across the different interfaces northward without significantly changing the AASW δ30Si. By comparing our new results with a previous study in the Australian sector we show that during the circumpolar transport of the ACC eastward, there is a slight but significant Si-isotopic lightening of the silicic acid pools from the Atlantic to the Australian sectors. This results either from the dissolution of biogenic silica in the deeper layers and/or from an isopycnal mixing with the deep water masses in the different oceanic basins: North Atlantic Deep Water in the Atlantic, and Indian Ocean deep water in the Indo-Australian sector. This eastward lightening is further transmitted to the subsurface waters, representing mixing interfaces between the surface and deeper layers. Using the Si-isotopic constraint, we estimate for the Greenwich Meridian a net biogenic silica production which should be representative of the annual export, at 4.5 ± 1.1 and 1.5 ± 0.4 mol Si m−2 for the Antarctic Zone and Polar Front Zone, respectively, in agreement with previous estimations. The summertime Si-supply into the mixed layer via vertical mixing was also assessed at 1.5 ± 0.4 and 0.1 ± 0.5 mol Si m−2, respectively.

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Water masses in the Atlantic Ocean: characteristics and distributions

Ocean Science ◽

10.5194/os-17-463-2021 ◽

2021 ◽

Vol 17 (2) ◽

pp. 463-486

Author(s):

Mian Liu ◽

Toste Tanhua

Keyword(s):

Atlantic Ocean ◽

Deep Water ◽

Bottom Water ◽

Water Mass ◽

Sea Water ◽

Weddell Sea ◽

Water Masses ◽

Global Ocean ◽

Intermediate Water ◽

The North

Abstract. A large number of water masses are presented in the Atlantic Ocean, and knowledge of their distributions and properties is important for understanding and monitoring of a range of oceanographic phenomena. The characteristics and distributions of water masses in biogeochemical space are useful for, in particular, chemical and biological oceanography to understand the origin and mixing history of water samples. Here, we define the characteristics of the major water masses in the Atlantic Ocean as source water types (SWTs) from their formation areas, and map out their distributions. The SWTs are described by six properties taken from the biased-adjusted Global Ocean Data Analysis Project version 2 (GLODAPv2) data product, including both conservative (conservative temperature and absolute salinity) and non-conservative (oxygen, silicate, phosphate and nitrate) properties. The distributions of these water masses are investigated with the use of the optimum multi-parameter (OMP) method and mapped out. The Atlantic Ocean is divided into four vertical layers by distinct neutral densities and four zonal layers to guide the identification and characterization. The water masses in the upper layer originate from wintertime subduction and are defined as central waters. Below the upper layer, the intermediate layer consists of three main water masses: Antarctic Intermediate Water (AAIW), Subarctic Intermediate Water (SAIW) and Mediterranean Water (MW). The North Atlantic Deep Water (NADW, divided into its upper and lower components) is the dominating water mass in the deep and overflow layer. The origin of both the upper and lower NADW is the Labrador Sea Water (LSW), the Iceland–Scotland Overflow Water (ISOW) and the Denmark Strait Overflow Water (DSOW). The Antarctic Bottom Water (AABW) is the only natural water mass in the bottom layer, and this water mass is redefined as Northeast Atlantic Bottom Water (NEABW) in the north of the Equator due to the change of key properties, especially silicate. Similar with NADW, two additional water masses, Circumpolar Deep Water (CDW) and Weddell Sea Bottom Water (WSBW), are defined in the Weddell Sea region in order to understand the origin of AABW.

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Late Quaternary paleoceanography of deep and intermediate water masses off Gaspé Peninsula, Gulf of St. Lawrence: foraminiferal evidence

Canadian Journal of Earth Sciences ◽

10.1139/e93-120 ◽

1993 ◽

Vol 30 (7) ◽

pp. 1390-1403 ◽

Cited By ~ 23

Author(s):

Cyril G. Rodrigues ◽

James A. Ceman ◽

Gustavs Vilks

Keyword(s):

Deep Water ◽

Water Mass ◽

Late Quaternary ◽

Water Masses ◽

Intermediate Water ◽

Low Salinity ◽

New Information ◽

Intermediate Water Mass ◽

Gaspe Peninsula ◽

Gaspé Peninsula

Radiocarbon-dated benthonic foraminiferal zones in three cores provide new information on the evolution of the deep and intermediate water masses off Gaspé Peninsula. The deglacial phase in the deep Laurentian Channel began before 14 000 BP and was characterized by low-salinity (<20‰) or alternating low-salinity and saline (~35‰) water. This was followed by a cold saline phase, which ended ca. 13 500 BP, and a salinity minimum (30–33.5‰), which began ca. 12 100 BP. Between 8700 and 7900 BP, the temperature and salinity of the deep water mass increased, resulting in the modern deep water mass (temperature 4–6 °C, salinity 34.5–34.9‰) at the end of the Goldthwait Sea episode. The salinity of the deep water was apparently controlled by the meltwater flux from the ice front during the deglacial phase. After the deglacial phase the characteristics of the deep water mass were determined by the composition of offshore water entering the Laurentian Channel. Runoff from the Lake Agassiz – Great Lakes system does not appear to have mixed with the deep water of the Goldthwait Sea. The deglacial phase in Chaleur Trough, which is within the intermediate water mass, began before 12 200 BP. The temperature of the intermediate water mass has remained close to 0 °C after deglaciation; however, the salinity has increased from 25–30‰ at 12 200 BP to about 33.5‰ by 5900 BP.

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Vertical Distribution of Atlantic Halibut (Hippoglossus hippoglossus) Eggs

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f84-092 ◽

1984 ◽

Vol 41 (5) ◽

pp. 798-804 ◽

Cited By ~ 27

Author(s):

Tore Haug ◽

Elin Kjørsvik ◽

Per Solemdal

Keyword(s):

Vertical Distribution ◽

Water Masses ◽

Atlantic Halibut ◽

Intermediate Water ◽

Specific Density ◽

Neutral Buoyancy ◽

Hippoglossus Hippoglossus ◽

Seawater Salinity ◽

Water Layers ◽

The Vertical Distribution

It is suggested that the vertical distribution of Atlantic halibut (Hippoglossus hippoglossus) eggs is determined by their specific density and that it is closely correlated to seawater salinity. In two deep North Norwegian fjords, only one halibut egg was found near the bottom (approximately 5200 m3 seawater filtered), while 278 eggs were found floating pelagically in intermediate water layers (approximately 190 000 m3 seawater filtered). Eggs were most abundant in water masses where temperature and salinity ranged between 4.5 and 7.0 °C and 33.8 and 35 0‰. Neutral buoyancy salinity measurements of living eggs corresponded approximately with the observed capture salinities. Mean capture salinity was 34.2 ± 0.3‰ (Malangen) and 34.5 ± 0.4‰ (Sørøysund). Egg diameters ranged from 3.06 to 3.49 mm.

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Carbonate system buffering in the water masses of the Southwest Atlantic sector of the Southern Ocean during February–March 2008

Biogeosciences Discussions ◽

10.5194/bgd-8-435-2011 ◽

2011 ◽

Vol 8 (1) ◽

pp. 435-462

Author(s):

M. González-Dávila ◽

J. M. Santana-Casiano ◽

R. A. Fine ◽

J. Happell ◽

B. Delille ◽

...

Keyword(s):

Southern Ocean ◽

Deep Water ◽

Frontal Zone ◽

Water Masses ◽

Intermediate Water ◽

Carbonate System ◽

Atlantic Sector ◽

Circumpolar Deep Water ◽

The Antarctic

Abstract. Carbonate system variables were measured in the South Atlantic sector of the Southern Ocean along a transect from South Africa to the southern limit of the Antarctic Circumpolar Current (ACC) in February–March 2008. Eddies detach from retroflection of the Agulhas Current located north of the Subantarctic Front (SAF). The eddies increase the gradients observed at the fronts so that minima in fCO2 and maxima in pH in situ on either side of the frontal zone are observed, while within the frontal zone fCO2 reached maximum values and pH in situ was a minimum. Mixing at the frontal zones, in particular where cyclonic rings were located, brought up CO2-rich water (low pH and high nutrient) that spread out the fronts where recent biological production favored by the nutrient input increases the pH in situ and decreases the fCO2 levels. Vertical distributions of water masses were described by their carbonate system properties and their relationship to CFC concentrations. Upper Circumpolar Deep Water (UCDW) and Lower Circumpolar Deep Water (LCDW) had pHT,25 values of 7.56 and 7.61, respectively. UCDW also had higher concentrations of CFC-12 (>0.2 pmol kg−1) as compared to deeper waters, revealing the mixing with recently ventilated waters. Calcite and aragonite saturation states (Ω) were also affected by the presence of these two water masses with high carbonate concentration. Ωarag = 1 was observed at 1000 m in the subtropical area and north of the SAF. At the position of the Polar front and under the influence of UCDW and LCDW Ωarag = 1 deepen from 600 m to 1500 m at 50.37° S, and it reaches to 700 m south of 57.5° S. High latitudes are the most sensitive areas under future anthropogenic carbon increase. Buffer coefficients related to changes in [CO2], [H+] and Ω with changes in CT and AT showed the minimum values are found in the Antarctic Intermediate Water (AAIW), and UCDW layers. These coefficients suggest that a small increase in CT will sharply decrease the pH and the carbonate saturation states. Here we present data that are used to suggest that south of 55° S by the year 2045 surface water will be undersaturated in aragonite.

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Characteristics of Water Masses in the Atlantic Ocean based on GLODAPv2 data

10.5194/os-2018-139 ◽

2019 ◽

Cited By ~ 1

Author(s):

Mian Liu ◽

Toste Tanhua

Keyword(s):

Atlantic Ocean ◽

North Atlantic ◽

Deep Water ◽

Bottom Water ◽

South Atlantic ◽

Weddell Sea ◽

Water Masses ◽

Intermediate Water ◽

South Atlantic Central Water ◽

The North

Abstract. The characteristics of the main water masses in the Atlantic Ocean are investigated and defined as Source Water Types (SWTs) from their formation area by six key properties based on the GLODAPv2 observational data. These include both conservative (potential temperature and salinity) and non-conservative (oxygen, silicate, phosphate and nitrate) variables. For this we divided the Atlantic Ocean into four vertical layers by distinct potential densities in the shallow and intermediate water column, and additionally by concentration of silicate in the deep waters. The SWTs in the upper/central water layer originates from subduction during winter and are defined as central waters, formed in four distinct areas; East North Atlantic Central water (ENACW), West North Atlantic Central Water (WNACW), East South Atlantic Central Water (ESACW) and West South Atlantic Central Water (WSACW). Below the upper/central layer the intermediate layer consist of three main SWTs; Antarctic Intermediate Water (AAIW), Subarctic Intermediate Water (SAIW) and Mediterranean Overflow Water (MOW). The North Atlantic Deep Water (NADW) is the dominating SWT in the deep and overflow layer, and is divided into upper and lower NADW based on the different origins and properties. The origin of both the upper and lower NADW is the Labrador Sea Water (LSW), the Iceland–Scotland Overflow Water (ISOW) and Denmark Strait Overflow Water (DSOW). Antarctic Bottom Water (AABW) is the only natural SWT in the bottom layer and this SWT is redefined as North East Atlantic Bottom Water (NEABW) in the north of equator due to the change of key properties, especial silicate. Similar with NADW, two additional SWTS, Circumpolar Deep Water (CDW) and Weddell Sea Bottom Water (WSBW), are defined in the Weddell Sea in order to understand the origin of AABW. The definition of water masses in biogeochemical space is useful for, in particular, chemical and biological oceanography to understand the origin and mixing history of water samples.

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Aegean Sea Water Masses during the Early Stages of the Eastern Mediterranean Climatic Transient (1988–90)

Journal of Physical Oceanography ◽

10.1175/jpo2940.1 ◽

2006 ◽

Vol 36 (9) ◽

pp. 1841-1859 ◽

Cited By ~ 55

Author(s):

I. Gertman ◽

N. Pinardi ◽

Y. Popov ◽

A. Hecht

Keyword(s):

Surface Water ◽

Deep Water ◽

Water Mass ◽

Sea Water ◽

Eastern Mediterranean ◽

Aegean Sea ◽

Water Masses ◽

Intermediate Water ◽

Central Basin ◽

Cretan Sea

Abstract The Aegean water masses and circulation structure are studied via two large-scale surveys performed during the late winters of 1988 and 1990 by the R/V Yakov Gakkel of the former Soviet Union. The analysis of these data sheds light on the mechanisms of water mass formation in the Aegean Sea that triggered the outflow of Cretan Deep Water (CDW) from the Cretan Sea into the abyssal basins of the eastern Mediterranean Sea (the so-called Eastern Mediterranean Transient). It is found that the central Aegean Basin is the site of the formation of Aegean Intermediate Water, which slides southward and, depending on their density, renews either the intermediate or the deep water of the Cretan Sea. During the winter of 1988, the Cretan Sea waters were renewed mainly at intermediate levels, while during the winter of 1990 it was mainly the volume of CDW that increased. This Aegean water mass redistribution and formation process in 1990 differed from that in 1988 in two major aspects: (i) during the winter of 1990 the position of the front between the Black Sea Water and the Levantine Surface Water was displaced farther north than during the winter of 1988 and (ii) heavier waters were formed in 1990 as a result of enhanced lateral advection of salty Levantine Surface Water that enriched the intermediate waters with salt. In 1990 the 29.2 isopycnal rose to the surface of the central basin and a large volume of CDW filled the Cretan Basin. It is found that, already in 1988, the 29.2 isopycnal surface, which we assume is the lowest density of the CDW, was shallower than the Kassos Strait sill and thus CDW egressed into the Eastern Mediterranean.

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Tracing Water Mass Mixing From the Equatorial to the North Pacific Ocean With Dissolved Neodymium Isotopes and Concentrations

Frontiers in Marine Science ◽

10.3389/fmars.2020.603761 ◽

2021 ◽

Vol 7 ◽

Author(s):

Michael Fuhr ◽

Georgi Laukert ◽

Yang Yu ◽

Dirk Nürnberg ◽

Martin Frank

Keyword(s):

Pacific Ocean ◽

Deep Water ◽

Surface Waters ◽

North Pacific ◽

Water Mass ◽

North Pacific Ocean ◽

Water Masses ◽

Intermediate Water ◽

Nd Isotope ◽

Geochemical Tracers

The sluggish water mass transport in the deeper North Pacific Ocean complicates the assessment of formation, spreading and mixing of surface, intermediate and deep-water masses based on standard hydrographic parameters alone. Geochemical tracers sensitive to water mass provenance and mixing allow to better characterize the origin and fate of the prevailing water masses. Here, we present dissolved neodymium (Nd) isotope compositions (εNd) and concentrations ([Nd]) obtained along a longitudinal transect at ∼180°E from ∼7°S to ∼50°N. The strongest contrast in Nd isotope signatures is observed in equatorial regions between surface waters (εNd ∼0 at 4.5°N) and Lower Circumpolar Deep Water (LCDW) prevailing at 4500 m depth (εNd = −6.7 at 7.2°N). The Nd isotope compositions of equatorial surface and subsurface waters are strongly influenced by regional inputs from the volcanic rocks surrounding the Pacific, which facilitates the identification of the source regions of these waters and seasonal changes in their advection along the equator. Highly radiogenic weathering inputs from Papua-New-Guinea control the εNd signature of the equatorial surface waters and strongly alter the εNd signal of Antarctic Intermediate Water (AAIW) by sea water-particle interactions leading to an εNd shift from −5.3 to −1.7 and an increase in [Nd] from 8.5 to 11.0 pmol/kg between 7°S and 15°N. Further north in the open North Pacific, mixing calculations based on εNd, [Nd] and salinity suggest that this modification of the AAIW composition has a strong impact on intermediate water εNd signatures of the entire region allowing for improved identification of the formation regions and pathways of North Pacific Intermediate Water (NPIW). The deep-water Nd isotope signatures indicate a southern Pacific origin and subsequent changes along its trajectory resulting from a combination of water mass mixing, vertical processes and Nd release from seafloor sediments, which precludes Nd isotopes as quantitative tracers of deep-water mass mixing. Moreover, comparison with previously reported data indicates that the Nd isotope signatures and concentrations below 100 m depth essentially remained stable over the past decades, which suggests constant impacts of water mass advection and mixing as well as of non-conservative vertical exchange and bottom release.

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