Vertical Distribution of Atlantic Halibut (Hippoglossus hippoglossus) Eggs

1984 ◽  
Vol 41 (5) ◽  
pp. 798-804 ◽  
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.

Recent changes of the salinity distribution in the South Adriatic

2020 ◽  
Author(s):  
Elena Mauri ◽  
Milena Menna ◽  
Giulio Notarstefano ◽  
Riccardo Gerin ◽  
Riccardo Martellucci ◽  
...  
Keyword(s):  
Vertical Distribution ◽  
Point Of View ◽  
Intermediate Water ◽  
The South ◽  
Low Salinity ◽  
Dense Water Formation ◽  
Subsurface Layers ◽  
Spatio Temporal ◽  
Biogeochemical Parameters ◽  
The Vertical Distribution

<p>The South Adriatic is one of the dense water formation site in the Mediterranean Sea. The variations of its thermohaline properties are relevant not only from an oceanographic and climatic point of view but also for the local impact on the vertical distribution of the biogeochemical parameters.</p><p>The South Adriatic Pit has been extensively sampled during the last forty years by traditional shipboard techniques. Float and glider measurements became part of the investigation only in the last ten years, providing a more detailed and more uniform spatio-temporal dataset. From the analysis, evidences of important changes of the South Adriatic Pit salinity vertical distribution emerge in the last 5 years. In the past, the Levantine Intermediate Water (LIW) entered the South Adriatic at a depth between 100 and 300 m, highlighted by a maximum in the salinity. The recent findings suggest that the LIW is no longer characterized by the highest salinity along the vertical profiles, which is present instead in shallower subsurface layers. In addition, in most of the seasons a thick low salinity layer is evident in the top 50-100 m. Among those changes, some peculiar haline characteristics occur in 2012 and 2017; they will be analyzed in concert with auxiliary data and model outputs.</p>

scholarly journals A Net for Catching Plankton near the Bottom

1928 ◽  
Vol 15 (1) ◽  
pp. 105-108 ◽  
Author(s):  
F. S. Russell
Keyword(s):  
Vertical Distribution ◽  
Sea Floor ◽  
Sea Bottom ◽  
Water Layers ◽  
Living Organisms ◽  
The Vertical Distribution

In the course of the researches on the vertical distribution of plankton it became evident that a net was needed for sampling the water-layers very close to the sea bottom. While the net had to be efficient in capturing the plankton animals present in those layers, it was necessary that the catches should not be vitiated by the presence of bottom-living organisms which had been stirred up from the sea floor by the net itself.

scholarly journals The Vertical Distribution of Marine Macroplankton. An Observation on Diurnal Changes

1925 ◽  
Vol 13 (4) ◽  
pp. 769-809 ◽  
Author(s):  
F. S. Russell
Keyword(s):  
Vertical Distribution ◽  
Full Moon ◽  
Diurnal Changes ◽  
Fair Weather ◽  
Sea Floor ◽  
Maximum Abundance ◽  
Graphic Record ◽  
Water Layers ◽  
The Vertical Distribution ◽  
Diurnal Behaviour

INTRODUCTION.1. A series of hauls with the ring-trawl were made at five depths in water 50 metres deep, so that samples were obtained approximately in daylight, at dusk, at midnight, at dawn, and again in daylight.A depth-recorder was used with the net giving a graphic record of its path through the water.2. Examination of the catches demonstrated the diurnal changes in vertical distribution of the species caught by the ring-trawl.3. Four types of behaviour were shown:—(a) A definite migration to the surface in the dark hours of certain forms living in the deeper layers in the daytime.(b) An expanding of the distribution of other organisms, that in the daytime had a zone of maximum abundance in the deeper layers, so that they were evenly scattered from the surface downwards.(c) Certain animals showed no or very little change in their vertical distribution during the dark hours.(d) A movement up to the midwater region by those forms that during the daytime adopt either a truly benthic existence or are congregated in the water layers immediately adjacent to the sea floor.(Lists of species grouped under their respective types of behaviour are to be found on page 780.)4. Many such observations are required before conclusions can be drawn as to the normal diurnal behaviour of plankton animals: this is a definite record of what occurred in this locality in mid-July at a period of full moon in fair weather.

scholarly journals Larval fish of the Campos Basin, southeastern Brazil

Check List ◽  
2012 ◽  
Vol 8 (6) ◽  
pp. 1280 ◽  
Author(s):  
Ana Cristina Teixeira Bonecker ◽  
Mário Katsuragawa ◽  
Márcia Salustiano de Castro ◽  
Eduardo De Araújo Pinto Gomes ◽  
Cláudia Akemi Pereira Namiki ◽  
...  
Keyword(s):  
Deep Water ◽  
Larval Fish ◽  
Fish Larvae ◽  
Mesh Size ◽  
Water Masses ◽  
Southeastern Brazil ◽  
Brazilian Coast ◽  
Intermediate Water ◽  
Campos Basin ◽  
The Vertical Distribution

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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