Vertical distribution of pilchard (Sardinops sagax) eggs and larvae off Southern Australia

1999 ◽  
Vol 50 (2) ◽  
pp. 117 ◽  
Author(s):  
W. J. Fletcher
Keyword(s):  
Vertical Distribution ◽  
Accurate Estimation ◽  
Relative Depth ◽  
Sardinops Sagax ◽  
Bottom Depth ◽  
Shelf Region ◽  
Opening And Closing ◽  
Egg Stages ◽  
Eggs And Larvae ◽  
Egg Abundance

Plankton samples were obtained from four to six discrete depths at 33 stations in July 1994 by using the ‘EZ’ multiple opening and closing net during a cruise along the shelf region from Adelaide to Albany, southern Australia. At the 19 stations (88 tows) where pilchard eggs were common, recently spawned eggs were most abundant at depths of 40–60 m, or 60% of total bottom depth. Most older egg stages were found closer to, or at, the surface. During day-time, most pilchard larvae were caught at the surface. At night, pilchard larvae appeared to spread out, with lower overall rates of capture but a bigger proportion caught below the surface. The effects of these changes in relative depth with age are discussed in relation to the accurate estimation pilchard egg abundance for biomass calculations.

scholarly journals ANALYSIS OF THE VERTICAL DISTRIBUTION OF THE ABUNDANCE OF SMALL PELAGIC FISH LARVAE IN THE GULF OF CALIFORNIA USING SUBMARINE VIDEOCAMERAS

2009 ◽  
Vol 24 (2) ◽  
pp. 153
Author(s):  
G. Aceves-Medina ◽  
C. J. Robinson ◽  
R. Palomares-García ◽  
J. Gómez-Gutierrez
Keyword(s):  
Vertical Distribution ◽  
Gulf Of California ◽  
Fish Larvae ◽  
Pelagic Fish ◽  
Small Pelagic Fish ◽  
Sardinops Sagax ◽  
Etrumeus Teres ◽  
Engraulis Mordax ◽  
The Vertical Distribution

Análisis de la distribucion vertical de la abundancia de larvas de peces pelágicos menores en el Golfo de California mediante videocámaras submarinas Se utilizaron dos tipos de videocámaras submarinas para estudiar la distribución y abundancia vertical de larvas de los peces pelágicos menores Engraulis mordax, Etrumeus teres y Sardinops sagax a 1 m de resolución, en una localidad en el norte del Golfo de California con condiciones de calma y alta densidad de sardinas adultas. La mayor abundancia promedio (900 larvas m -1 min -1 ) se encontró inmediatamente arriba de la termoclina (33 m) y la picnoclina (36 m), aparentemente no asociada al máximo de clorofila detectado en superficie, ni a la mayor densidad de peces adultos (10 -20 m). Las observaciones con video permitieron determinar la distribución vertical a una resolución imposible de obtener mediante muestreos con redes; sin embargo, esta es una técnica poco útil en zonas con elevada velocidad de las corrientes.

scholarly journals Vertical distribution of eggs and larvae of Maurolicus japonicus (Sternoptychidae, Pisces) in Tosa Bay, Japan

2019 ◽  
Vol 14 (2) ◽  
pp. 80-85
Author(s):  
Liezel C. Paraboles ◽  
Donna M. Guarte ◽  
Izumi Kinoshita
Keyword(s):  
Vertical Distribution ◽  
Tosa Bay ◽  
Eggs And Larvae

scholarly journals Buoyancy and vertical distribution of Norwegian coastal cod (Gadus morhua) eggs from different areas along the coast

2008 ◽  
Vol 65 (7) ◽  
pp. 1198-1202 ◽  
Author(s):  
Erling Kåre Stenevik ◽  
Svein Sundby ◽  
Ann Lisbeth Agnalt
Keyword(s):  
Vertical Distribution ◽  
Density Gradient ◽  
Surface Waters ◽  
Gadus Morhua ◽  
Genetic Differences ◽  
Marine Science ◽  
Norwegian Coast ◽  
Spawning Areas ◽  
Subsurface Waters ◽  
Eggs And Larvae

Abstract Stenevik, E. K., Sundby, S., and Agnalt, A. L. 2008. Buoyancy and vertical distribution of Norwegian coastal cod (Gadus morhua) eggs from different areas along the coast. – ICES Journal of Marine Science, 65: 1198–1202. There are significant genetic differences in coastal cod (Gadus morhua) along the Norwegian coast, and in order to maintain these differences, there must be mechanisms that ensure local retention of eggs and larvae in the spawning areas. The buoyancy of eggs from four different areas along the Norwegian coast was measured using a density gradient column, and the results from modelling experiments showed that in three of the groups (Tysfjord, Helgeland, and Øygarden), the buoyancy in combination with local hydrography would place the eggs in subsurface waters where retention is greater than in surface waters.

Vertical distribution of cod and haddock eggs and larvae, feeding and condition in stratified and mixed waters on southern Georges Bank, May 1992

1996 ◽  
Vol 43 (7-8) ◽  
pp. 1875-1904 ◽  
Author(s):  
R.Gregory Lough ◽  
Elaine M. Caldarone ◽  
Teresa K. Rotunno ◽  
Elisabeth A. Broughton ◽  
Bruce R. Burns ◽  
...  
Keyword(s):  
Vertical Distribution ◽  
Georges Bank ◽  
Eggs And Larvae

Spatial distribution of sardine (Sardinops sagax) eggs and larvae: an application of geostatistics and resampling to survey data

1999 ◽  
Vol 56 (6) ◽  
pp. 907-914 ◽  
Author(s):  
W J Fletcher ◽  
Neil R Sumner
Keyword(s):  
Spatial Distribution ◽  
Survey Data ◽  
Ordinary Kriging ◽  
Sampling Design ◽  
Optimal Sampling ◽  
Bootstrap Resampling ◽  
Two Dimensional ◽  
Optimal Sampling Design ◽  
Sardinops Sagax ◽  
Eggs And Larvae

The abundance of eggs and larvae of sardine (pilchard) (Sardinops sagax) off the south coast of Western Australia was investigated using geostatistical and bootstrap resampling techniques. A two-dimensional correlogram showed that the patch of newly spawned pilchard eggs had dimensions of 8 nautical miles (M) in diameter in the offshore direction and 10 M in the alongshore direction. For older stages, the size of the patch tended to increase and the level of cohesion decrease. It was more difficult to determine the size of the patch from directional variograms. The abundance of 1- and 2-day-old eggs in the study area was estimated using ordinary kriging. A bootstrapping analysis suggested that the optimal sampling design for day 1 eggs should use 4 × 10 M grids, an increase in intensity on the 5 × 15 M grids used in previous surveys.

Transport, Distribution, and Abundance of Larval and Juvenile Walleye Pollock (Theragra chalcogramma) in the Western Gulf of Alaska

1991 ◽  
Vol 48 (1) ◽  
pp. 91-98 ◽  
Author(s):  
Sarah Hinckley ◽  
Kevin M. Bailey ◽  
Susan J. Picquelle ◽  
James D. Schumacher ◽  
Phyllis J. Stabeno
Keyword(s):  
Early Life ◽  
Gulf Of Alaska ◽  
Walleye Pollock ◽  
Theragra Chalcogramma ◽  
Life Stages ◽  
Early Life Stages ◽  
Early Juvenile ◽  
Walleye Pollock Theragra Chalcogramma ◽  
Eggs And Larvae ◽  
Egg Abundance

The spawning distribution of walleye pollock (Theragra chalcogramma) and subsequent southwesterly drift of eggs, larvae, and juveniles were investigated in Shelikof Strait, March–September 1987. In mid-March, a hydroacoustics survey found that spawning adults were concentrated in the deeper parts of Shelikof Strait, as were eggs collected in this area during an ichthyoplankton survey about 1 mo later. In May, a concentration of young larvae was found 100–150 km to the southwest of the spawning area. In late June and early July, the center of distribution of late larval and early juvenile walleye pollock was further to the southwest, between the Shumagin and Semidi Islands. By August and September, juveniles were mostly distributed downstream of the Shumagin Islands. The rate of drift of eggs and larvae through June was estimated at 4–6 cm/s. The trajectories of satellite-tracked buoys deployed in the region of greatest egg abundance revealed similar patterns to those of the early life stages of walleye pollock. These observations demonstrate that transport is an important factor determining the distribution of pollock larvae in downstream coastal nursery areas.

Distribution and Abundance of Haddock (Melanogrammus aeglefinus) and Atlantic Cod (Gadus morhua) Eggs and Larvae in the Waters off Southwest Nova Scotia

1989 ◽  
Vol 46 (S1) ◽  
pp. s103-s112 ◽  
Author(s):  
Peter C. F. Hurley ◽  
Steven E. Campana
Keyword(s):  
Nova Scotia ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Melanogrammus Aeglefinus ◽  
Eggs And Larvae ◽  
Haddock Melanogrammus Aeglefinus ◽  
Egg Abundance

Synoptic ichthyoplankton surveys conducted at monthly intervals during the winter–spring of 1983–85 were used to determine the location, timing, and magnitude of spawning by haddock (Melanogrammus aeglefinus) and Atlantic cod (Gadus morhua) off southwest Nova Scotia. There was a marked similarity in the spawning locations of the two species: primary spawning occurred on Browns Bank, although lower levels of spawning were observed on adjacent banks and in the inshore region. Cod egg abundance peaked in April in all years, while that of haddock varied between April–June.

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