scholarly journals Zooplankton diel vertical migration in the Corsica Channel (north-western Mediterranean Sea) detected by a moored ADCP

2018 ◽  
Author(s):  
Davide Guerra ◽  
Katrin Schroeder ◽  
Mireno Borghini ◽  
Elisa Camatti ◽  
Marco Pansera ◽  
...  
Keyword(s):  
Water Column ◽  
Vertical Migration ◽  
Diel Vertical Migration ◽  
Western Mediterranean ◽  
Late Winter ◽  
Surface Layers ◽  
Western Mediterranean Sea ◽  
Deep Layers ◽  
Migratory Patterns ◽  
Bottom Depth

Abstract. Diel vertical migration (DVM) is a survival strategy adopted by zooplankton, that was investigated in the Corsica Channel using ADCP data, from April 2014 to November 2016. The principal aim of the study is to characterize migratory patterns and biomass temporal evolution along the water column. The ADCP measured vertical velocity and echo intensity in the water column range between about 70 m and 390 m (the bottom depth is 443 m). In addition, net samples were taken during summer 2015 at the same location. During the investigated period, biomass had a well-defined daily and seasonal cycle, with peaks occurring in late winter–spring, when the stratification of water column is weaker. Biomass evolution along the whole water column is well correlated with primary production estimated with satellite data. Blooming and no-blooming periods have been identified and studied separately. During the no-blooming period biomass was most abundant in the surface and the deep layers, while during the blooming period the surface maximum disappeared and the deep layer with high biomass became thicker. These two layers are likely to correspond to two different zooplanktonic communities. Nocturnal DVM appears to be the main pattern during both periods, but also reverse and twilight migration are detected. Nocturnal DVM was more evident at mid-water than near in the deep and the surface layers. DVM occurred with different intensities in blooming and no-blooming periods, and phenomena like nocturnal sinking were found to be stronger during the blooming period. One of the main outcomes is that the principal drivers for DVM are light intensity and stratification, but also others are taken in consideration.

scholarly journals Zooplankton diel vertical migration in the Corsica Channel (north-western Mediterranean Sea) detected by a moored acoustic Doppler current profiler

Ocean Science ◽  
2019 ◽  
Vol 15 (3) ◽  
pp. 631-649 ◽  
Author(s):  
Davide Guerra ◽  
Katrin Schroeder ◽  
Mireno Borghini ◽  
Elisa Camatti ◽  
Marco Pansera ◽  
...  
Keyword(s):  
Water Column ◽  
Vertical Migration ◽  
Diel Vertical Migration ◽  
Temporal Distribution ◽  
Acoustic Doppler Current Profiler ◽  
Western Mediterranean ◽  
Late Winter ◽  
Western Mediterranean Sea ◽  
Current Profiler ◽  
Deep Layers

Abstract. Diel vertical migration (DVM) is a survival strategy adopted by zooplankton that we investigated in the Corsica Channel using acoustic Doppler current profiler (ADCP) data from April 2014 to November 2016. The principal aim of the study is to characterize migration patterns and biomass temporal evolution of zooplankton along the water column. The ADCP measured vertical velocity and echo intensity in the water column range between about 70 and 390 m (the bottom depth is 443 m). During the investigated period, zooplanktonic biomass had a well-defined daily and seasonal cycle, with peaks occurring in late winter to spring (2015 and 2016) when the stratification of the water column is weaker. Zooplanktonic biomass temporal distribution in the whole water column is well correlated with biomass of primary producers, estimated with satellite data. Zooplanktonic blooming and non-blooming periods have been identified and studied separately. During the non-blooming period zooplanktonic biomass was most abundant in the upper and the deep layers, while during the blooming period the upper-layer maximum in zooplanktonic biomass disappeared and the deep layer with high zooplanktonic biomass became thicker. These two layers are likely to correspond to two different zooplanktonic communities. The evolution of zooplanktonic biomass is well correlated with chlorophyll, with phytoplankton biomass peaks preceding the upper-layer secondary production by a lag of about 3.5 weeks. Nocturnal DVM appears to be the main pattern during both periods, but reverse and twilight migration are also detected. Nocturnal DVM was more evident at mid-water than in the deep and the upper layers. DVM occurred with different intensities during blooming and non-blooming periods. One of the main outcomes is that the principal drivers for DVM are light intensity and stratification, but other factors, like the moon cycle and primary production, are also taken in consideration.

scholarly journals Patterns of distribution and abundance of larval phosichthyidae (actinopterygii, stomiiformes) in southeastern Brazilian waters

2011 ◽  
Vol 59 (3) ◽  
pp. 213-229 ◽  
Author(s):  
Cássia Gôngora Goçalo ◽  
Mario Katsuragawa ◽  
Ilson Carlos Almeida da Silveira
Keyword(s):  
Vertical Distribution ◽  
Water Column ◽  
Vertical Migration ◽  
Diel Vertical Migration ◽  
Distribution Patterns ◽  
Southeastern Brazil ◽  
Patterns Of Distribution ◽  
Oceanic Region ◽  
Brazil Current ◽  
Horizontal And Vertical Distribution

Horizontal and vertical distribution patterns and abundance of larval phosichthyids were investigated from oblique and depth-stratified towns off Southeastern brazilian waters, from São Tomé cape (41ºW.; 22ºS.) to São Sebastião island (45ºW.; 24ºS.). The sampling was performed during two cruises (January/2002 -summer; August/2002 -winter). Overall 538 larvae of Phosichthyidae were collected during summer and 158 in the winter. Three species, Pollichthys mauli, Vinciguerria nimbaria and Ichthyioccoccus sp. occurred in the area, but Ichthyioccoccus sp. was extremely rare represented by only one specimen, caught in the oceanic region during the summer. Geographically, larval were concentrated in the oceanic region, and vertically distributed mainly between the surface and 80 m depth in the summer and winter. Larvae were more abundant during the night, performing a diel vertical migration in the water column. The results suggest that the meandering and eddies of Brazil Current play important role on the transport and distribution patterns of larval phosichthyids over the oceanic and neritic area in the Southeastern Brazil.

Diel Vertical Migration and Feeding Behavior of a Demersal Hydromedusan (Polyorchis penicillatus)

1984 ◽  
Vol 41 (12) ◽  
pp. 1837-1843 ◽  
Author(s):  
S. A. Arkett
Keyword(s):  
Feeding Behavior ◽  
Water Column ◽  
Vertical Migration ◽  
Diel Vertical Migration ◽  
Small Amplitude ◽  
Prey Density ◽  
Polyorchis Penicillatus ◽  
Emergence Traps ◽  
Invertebrate Larvae ◽  
Demersal Zooplankton

The hydromedusan Polyorchis penicillatus makes a small amplitude diel vertical migration. During the day, over 85% of the individuals were observed within 1 m of the bottom, while at night, medusae diffused several metres up into the water column. This movement occurred concomitantly with the emergence of many of the major taxa of demersal Zooplankton whose activity was quantified by emergence traps. Food boli contents collected from Polyorchis showed some selectivity for large, fast-moving demersal plankters and low capture and utilization of invertebrate larvae. Diel shifts in feeding behavior and water column position enable Polyorchis to feed efficiently on high densities of demersal plankters at all times. Medusae may be exempt from migration constraints imposed by visual predators and are thus able to move into areas of high prey density to supply energetic requirements. Hydromedusae, such as Polyorchis, are shown to utilize a variety of factors, such as tentacle position and swimming speed, in an "ambush" strategy to optimize prey encounters.

scholarly journals 228Ra/226Ra and 226Ra/Ba ratios in the Western Mediterranean Sea: Barite formation and transport in the water column

2009 ◽  
Vol 73 (16) ◽  
pp. 4720-4737 ◽  
Author(s):  
P. van Beek ◽  
E. Sternberg ◽  
J.-L. Reyss ◽  
M. Souhaut ◽  
E. Robin ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Water Column ◽  
Western Mediterranean ◽  
Western Mediterranean Sea

Acoustic Analysis of Diel Vertical Migration Behavior of Mysis relicta and Kokanee (Oncorhynchus nerka) within Okanagan Lake, British Columbia

1991 ◽  
Vol 48 (1) ◽  
pp. 67-72 ◽  
Author(s):  
David A. Levy
Keyword(s):  
Water Column ◽  
Vertical Migration ◽  
Diel Vertical Migration ◽  
Acoustic Analysis ◽  
Oncorhynchus Nerka ◽  
Target Strength ◽  
Migration Behavior ◽  
Mysis Relicta ◽  
Dual Beam ◽  
Diel Vertical Migrations

Dual-beam acoustic surveys of Okanagan Lake suggested active diel vertical migrations of Mysis relicta and kokanee (Oncorhynchus nerka) within the pelagic zone. Mysis relicta were situated between 90–150 m during the day and migrated upwards into the thermocline region of the water column at night. Two groups of kokanee targets were detected. The first undertook a diel vertical migration and coalesced at dusk with a second, shallow-oriented group of targets. Daytime target strength estimates taken while the two groups were vertically segregated in the water column suggested an 8–12 db lower target strength of the deeper group. The results provide acoustic evidence for a smaller body size in the deeper group and the occurrence of an ontogenetic shift in diel migratory behavior of kokanee within Okanagan Lake. Diel comparisons of depth distribution suggested spatial segregation of Mysis and kokanee over much of the diel cycle.

Migratory patterns, vertical distributions and diets of Abralia veranyi and Abraliopsis morisii (Cephalopoda: Enoploteuthidae) in the eastern North Atlantic

2019 ◽  
Vol 86 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Airam Guerra-Marrero ◽  
Vicente Hernández-García ◽  
Airam Sarmiento-Lezcano ◽  
David Jiménez-Alvarado ◽  
Angelo Santana-del Pino ◽  
...  
Keyword(s):  
Canary Islands ◽  
North Atlantic ◽  
Vertical Migration ◽  
Diel Vertical Migration ◽  
Mantle Length ◽  
Migration Patterns ◽  
Ontogenetic Shifts ◽  
Vertical Distributions ◽  
Migratory Patterns ◽  
Eastern North Atlantic

Abstract Abralia veranyi and Abraliopsis morisii were the most abundant cephalopods caught during epipelagic and mesopelagic surveys off the Canary Islands and accounted for 26% and 35% of the cephalopod catch, respectively. Diel vertical migration patterns were observed in both species. At night, A. veranyi was recorded at depths as shallow as 38–90 m, whereas Abraliopsis morisii occurred at depths of 98–219 m. As individuals grow in mantle length, their diet changes substantially. Abraliopsis morisii showed ontogenetic shifts at 22.9 mm and 35.3 mm dorsal mantle length (DML), while A. veranyi showed ontogenetic shifts at 20.5 mm and 30.9 mm DML. Prior to the first ontogenic shift, both species fed mainly on copepods and mysids. After this shift they fed on larger prey, such as decapods and fish; the diets of larger individuals also contained cephalopods.

Diel Vertical Migration of Pandalus borealis in Kachemak Bay, Alaska

1970 ◽  
Vol 27 (4) ◽  
pp. 669-676 ◽  
Author(s):  
Louis Barr
Keyword(s):  
Water Column ◽  
Vertical Migration ◽  
Diel Vertical Migration ◽  
Bottom Trawling ◽  
Pandalus Borealis ◽  
Apparent Length ◽  
Large Numbers

Catches of Pandalus borealis by surface-to-bottom pot fishing in Kachemak Bay, Alaska, showed that this species was distributed in large numbers throughout the water column at night and suggested a diel vertical migration. The shrimp apparently left the vicinity of the bottom about dusk and returned about dawn; the apparent length of time they were off bottom was directly related to the length of the night. Bottom trawling clearly showed lower availability of P. borealis on bottom at night than during the day. Catches of shrimp by pot fishing and trawling indicated that small P. borealis have a greater tendency to migrate vertically than the larger individuals.

Nd isotopes as tracers in water column particles: the western Mediterranean Sea

1990 ◽  
Vol 30 ◽  
pp. 389-407 ◽  
Author(s):  
F.E. Grousset ◽  
F. Henry ◽  
J.F. Minster ◽  
A. Monaco
Keyword(s):  
Mediterranean Sea ◽  
Water Column ◽  
Western Mediterranean ◽  
Nd Isotopes ◽  
Western Mediterranean Sea
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