Spatial and temporal changes in biomass, production and assemblage structure of mesozooplanktonic copepods in the tropical south-west Atlantic Ocean

We examined the spatial and temporal variations of coastal and oceanic epipelagic copepods (rainy–dry seasons of 2009) in a tropical area of the south-west Atlantic. Zooplankton samples were obtained at 48 stations along six transects perpendicular to the coast, in the subsurface water between the 25 and 3000 m isobaths, by horizontal hauls using a Multinet. Abundance (42–64,753 ind. m−3), biomass (0.08–113 mg C m−3) and daily copepod production (0.17–163.20 mg C m−3 d−1) showed longitudinal and latitudinal variability. The highest values were observed over the southern continental shelf during the dry season. Temoridae, Undinula vulgaris and Paracalanus quasimodo dominated the biomass and daily copepod production during the rainy season; while Calanoides carinatus, Calanopia americana, Clausocalanidae, Temoridae, Paracalanidae and Subeucalanidae dominated during the dry season. The copepod assemblages formed four different groups: rainy season–continental shelf (1), dry season–continental shelf (2), rainy season–continental slope (3) and dry season–continental slope (4). Temperature, salinity, chlorophyll-a and suspended particulate matter explained 45% of the productivity distribution of the dominant copepod species. This study is the first attempt to examine the biomass and daily copepod production in oceanic waters in the south-west Atlantic Ocean, and it showed that copepod biomass and production in a tropical region can be relatively high compared with other regions of the world's oceans.

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On the occurrence and behaviour of two little-known barnacles, Hexelasma hirsutum and Verruca recta, from the continental slope

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315400005683 ◽

1958 ◽

Vol 37 (3) ◽

pp. 633-647 ◽

Cited By ~ 2

Author(s):

A. J. ◽

Eve C. Southward ◽

L. H. N. Cooper

Keyword(s):

Continental Shelf ◽

Continental Slope ◽

British Isles ◽

The South ◽

South West

The fauna of the continental shelf and slope between Ireland and Spain has been described by Le Danois (1948), but very little faunistic work has been carried out in the area recently. Since R.V. ‘Sarsia’ was brought into service at Plymouth there have been several opportunities of investigating that part of the slope lying to the south-west of the British Isles. It has been found that, in addition to beds of coral, quite extensive exposures of rocks, stones and gravel occur between 200 and 1000 fathoms. There is a rich epifauna in this area and barnacles are one of the dominant groups.

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Presence of the telescope fish Mendosoma lineatum in Patagonian waters, a new species in the ichthyological fauna from the south-west Atlantic Ocean

Journal of Fish Biology ◽

10.1111/jfb.13397 ◽

2017 ◽

Vol 91 (4) ◽

pp. 1224-1227 ◽

Cited By ~ 1

Author(s):

N. D. Bovcon ◽

P. D. Cochia ◽

J. Ruibal Núñez ◽

M. Vucica ◽

D. E. Figueroa

Keyword(s):

New Species ◽

Atlantic Ocean ◽

The South ◽

South West ◽

A New Species

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Relationships between environmental features, distribution and abundance of the Argentine anchovy, Engraulis anchoita, on the South West Atlantic Continental Shelf

Fisheries Research ◽

10.1016/j.fishres.2015.07.008 ◽

2016 ◽

Vol 173 ◽

pp. 229-235 ◽

Cited By ~ 8

Author(s):

Paloma Lumi Costa ◽

Pedro Ramiro Castillo Valderrama ◽

Lauro Antônio Saint Pastous Madureira

Keyword(s):

Continental Shelf ◽

The South ◽

Environmental Features ◽

South West

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Comparative effects of three seasons on seed population and viability of cattle, sheep and goat dungs in South-West Nigeria

Nigerian Journal of Animal Production ◽

10.51791/njap.v32i1.1052 ◽

2021 ◽

Vol 32 (1) ◽

pp. 94-101

Author(s):

A. O. Jolaosho ◽

J. A. Olanite ◽

B. O. Oduguwa ◽

E. A. O. Adekunle

Keyword(s):

Rainy Season ◽

Dry Season ◽

Sheep And Goats ◽

South West ◽

Three Samples ◽

Seed Population ◽

Higher Weights ◽

Ruminant Animals ◽

Viable Seeds ◽

Number Of Seeds

An experiment to determine the effects of seasonal variations on population and viability of seeds in the faeces of ruminant animals was conducted between April to December 2001 using two breeds of cattle, sheep and goats. Three samples were collected per breed from three animals that were tagged for uniformity of data collection. Sampling took place weekly, in the mornings before the animals were taken out for grazing. The highest (P<0.05) total number of seeds, seeds/g dry weights and total number of viable seeds were recovered from cattle, while the least were from goats, but the reverse was the case for percentage viability. The weights of the faeces were significantly (P<0.05) higher in the rainy season than the dry season. The weights of the faeces reduced gradually as the dry season sets in. Likewise, there were more seeds in the early rain than in the late rain and early dry season, with the percentage viability higher in the late rains and early dry season than the early rainy season. There were more broadleaved weeds and sedges in the early rain than late rain and early dry season but the reverse was the case for grasses. In conclusion, although there were more faeces and consequently more seed production in the rainy season, however, but the viability was lower than in the dry season. Also, seeds of broadleaved plants were more in the rainy season while those of grasses were more in the dry season. More seeds and number of viable seeds were recovered from the faeces of cattle than sheep and goats in all the seasons due to the higher weights of faeces but the percentage viability was higher for sheep and goat than cattle.

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Spatio-Temporal Variations of Hydrochemical and Microbial Characteristics in Karst Water in Samcheok, South Korea

Water ◽

10.3390/w12123407 ◽

2020 ◽

Vol 12 (12) ◽

pp. 3407

Author(s):

Han-Sun Ryu ◽

Heejung Kim ◽

Jin-Yong Lee ◽

Jiwook Jang ◽

Sangwook Park

Keyword(s):

Water Quality ◽

Rainy Season ◽

Temporal Variations ◽

Dry Season ◽

Quality Analysis ◽

Dominant Factor ◽

Karst Water ◽

Seasonal Characteristics ◽

Microbial Characteristics ◽

Spatio Temporal

This study analyzed the hydrochemical characteristics and microbial communities of karst water in Samcheok, Korea, and compared water quality results to identify the seasonal characteristics and hydrogeological connectivity of the study areas of Hamaengbang-ri, Gyogok-ri, Yeosam-ri, and the downtown area of Samcheok. Field survey and water quality analysis were performed in July 2019, February 2020, and April 2020. Hydrochemical analysis of karst water (groundwater and surface water) showed that most samples were comprised of Ca-HCO3 and that water–rock interactions were a dominant factor compared to precipitation and evaporation (crystallization). For seasonal characteristics, water–rock interactions appeared more active in the dry season than in the rainy season. Calcite weathering was dominant in the dry season, whereas dolomite weathering dominated the rainy season. Moreover, the saturation indexes for the dry and rainy seasons were less than and greater than 0, respectively, corresponding to an unsaturation (oversaturation) state; thus, white precipitate distributed in the study areas was deposited in the rainy season. Finally, as a result of analyzing the hydraulic characteristics between regions, hydrogeological similarities were identified between Hamaengbang-ri and Yeosam-ri, and between Gyogok-ri and downtown Samcheok, which suggested hydrogeological connectivity between each of the pairs.

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New records of octocorals (Cnidaria, Anthozoa) from the south western Atlantic Ocean, with zoogeographic considerations

Zootaxa ◽

10.11646/zootaxa.630.1.1 ◽

2004 ◽

Vol 630 (1) ◽

pp. 1 ◽

Cited By ~ 3

Author(s):

CARLOS D. PÉREZ ◽

MAURICIO O. ZAMPONI

Keyword(s):

Atlantic Ocean ◽

New Records ◽

American Continent ◽

The South ◽

Western Atlantic ◽

Western Atlantic Ocean ◽

East Pacific ◽

South West ◽

First Case ◽

Present Distribution

The present study deals with six new records of octocoral species (two alcyoniid soft corals and four primnoid gorgonians) for the south western Atlantic Ocean. These new records, mainly for the gorgonians, improves the knowledge of their present distribution. The species Thouarella koellikeri and Dasystenella acanthina have their known distribution widened, showing in the first case a continuous bioceanic distribution (south east Pacific south west Atlantic). The species of the genus Primnoella, P. biserialis and P. compressa, widen their distributional range tending to a geographical continuity along the south eastern coasts of the American continent, avoiding the zoogeographic barrier constituted by the R o de la Plata.

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III.—Picrite from the Ampwihi River, Mozambique

Geological Magazine ◽

10.1017/s0016756800192398 ◽

1917 ◽

Vol 4 (4) ◽

pp. 150-157 ◽

Cited By ~ 2

Author(s):

Arthur Holmes ◽

H. F. Harwood

Keyword(s):

Narrow Channel ◽

Dry Season ◽

The Other ◽

The South ◽

Eastern Side ◽

South West ◽

Western Side ◽

The Right ◽

Sand And Gravel ◽

The Military

Almost due west of Mozambique Island, at a distance of about forty-two miles from the sea, the military road from Mosuril to Nampula crosses the Ampwihi River, an important tributary of the Monapo. During the dry season the stream is reduced to a string of stagnant pools, separated by long reaches of sand and gravel that here and there are interrupted by outcrops of the underlying formations. Throughout the greater part of its course the Ampwihi flows through a region in which gneisses persist with monotonous regularity, the only variation being that due to occasional intrusions of granite and of still later pegmatite dykes. At the point where the military road crosses the narrow channel a welcome diversion is introduced by the presence of a dark compact dyke about 10 feet in thickness. The dyke appears on the right-hand bank and crosses obliquely to the other side, taking a N.N.W.–S.S.E. course across the strike of the older rocks. Upstream, about seventy yards to the south-east, the Ampwihi bends to the south-west, so that it returns towards the dyke, which is again exposed across its sandy floor. The dyke was traced by Mr. E. J. Wayland in July, 1911, for a distance of altogether 200 yards, and was examined by Mr. D. Alex. Wray and later by myself during the same year. It is clearly the latest rock of the district, and is intruded along a line of fault, for in two cases pegmatite dykes seen on the eastern side are broken across and reappear on the western side with a well-marked northerly displacement.

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Cascading Over the Continental Slope of Water from the Celtic Sea

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315400023547 ◽

1949 ◽

Vol 28 (3) ◽

pp. 719-750 ◽

Cited By ~ 55

Author(s):

L. H. N. Cooper ◽

David Vaux

Keyword(s):

Continental Shelf ◽

Continental Slope ◽

English Channel ◽

The South ◽

Celtic Sea

In the Celtic Sea, to the south of Ireland, water in some winters becomes sufficiently cooled and heavy to flow to the edge of the continental shelf and to run down the continental slope to a depth of several hundred metres. A theory of the phenomenon, termed ‘cascading’, has been developed. Three winters have been examined in detail.In February 1927 much water, heavy enough to cascade, was present in the Celtic Sea and also in the English Channel. A probable course and speed of the cascading water over the shelf has been established. Since there were few observations of salinity and temperature over or beyond the slope, and none of oxygen anywhere, the theory cannot be completely established on the basis of the 1927 observations, full though they were.

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