Seasonal vertical distribution and population dynamics of the chaetognath Parasagitta elegans in the water column and hyperbenthic zone of Conception Bay, Newfoundland

2000 ◽  
Vol 137 (5-6) ◽  
pp. 847-856 ◽  
Author(s):  
N. Choe ◽  
D. Deibel
Keyword(s):  
Population Dynamics ◽  
Vertical Distribution ◽  
Water Column ◽  
Conception Bay

UV radiation effects on the embryos of anchoveta (Engraulis ringens) and common sardine (Strangomera bentincki) off central Chile

2016 ◽  
Vol 67 (2) ◽  
pp. 195 ◽  
Author(s):  
P. Vásquez ◽  
A. Llanos-Rivera ◽  
L. R. Castro ◽  
C. Fernandez
Keyword(s):  
Vertical Distribution ◽  
Water Column ◽  
Radiation Effects ◽  
Hatching Success ◽  
Sublethal Effects ◽  
Ultraviolet B ◽  
Uvb Radiation ◽  
Central Chile ◽  
Fish Embryos ◽  
Engraulis Ringens

It has been proposed that current levels of ultraviolet B (UVB) radiation could cause lethal or sublethal effects on fish embryos located in the upper layers of the water column. Observed levels of UVB off central Chile (36°S, 73°W) indicate that planktonic fish embryos could be exposed to harmful UVB radiation. From July 2011 to January 2012 embryos from anchoveta (Engraulis ringens) and common sardine (Strangomera bentincki) were used to test experimentally whether the UVB levels in central Chile produce lethal or sublethal effects in epipelagic fish embryos. Simultaneously, whether the embryos might be exposed to harmful UVB levels in the field was investigated. Our experimental results show that UVB may cause a decrease in hatching success, changes in buoyancy and embryonic malformations. These results, along with the observed vertical distribution of embryos and UVB radiation levels in the field during late spring suggest that lethal and sublethal effects may be occurring in the embryos of both species.

scholarly journals Effects of Temperature and Salinity on Vibrio vulnificus Population Dynamics as Assessed by Quantitative PCR

2004 ◽  
Vol 70 (9) ◽  
pp. 5469-5476 ◽  
Author(s):  
Mark A. Randa ◽  
Martin F. Polz ◽  
Eelin Lim
Keyword(s):  
Population Dynamics ◽  
Water Temperature ◽  
Water Column ◽  
Quantitative Pcr ◽  
Vibrio Vulnificus ◽  
Most Probable Number ◽  
Salinity Regime ◽  
Optimal Salinity ◽  
Probable Number ◽  
Barnegat Bay

ABSTRACT The abundance of Vibrio vulnificus in coastal environments has been linked to water temperature, while its relationship to salinity is less clear. We have developed a culture-independent, most-probable-number quantitative PCR approach to examine V. vulnificus population dynamics in Barnegat Bay, N.J. Based on the combined analysis of our results from Barnegat Bay and from the literature, the present data show that (i) V. vulnificus population dynamics are strongly correlated to water temperature and (ii) although the general trend is for V. vulnificus abundance to be inversely correlated with salinity, this relationship depends on salinity levels. Irrespective of temperature, high abundances of V. vulnificus are observed at 5 to 10 ppt, which thus appears to be the optimal salinity regime for their survival. At 20 to 25 ppt, V. vulnificus abundances show a positive correlation to salinity. Unsuccessful attempts to resuscitate V. vulnificus, combined with our inability to detect cells during the winter despite an assay adapted to detect viable but nonculturable (VBNC) cells, suggest that the decline and eventual disappearance of V. vulnificus from the water column during the winter months is due primarily to a significant reduction in population size and is not only the consequence of cells entering the VBNC state. These findings are in line with the hypothesis that the sediment serves as a refuge for a subpopulation of V. vulnificus over the winter and weather-driven mixing events during the spring initiate a summer bloom in the water column.

Diel vertical distribution of early marine phase juvenile pink salmon (Oncorhynchus gorbuscha) and behaviour when exposed to salmon louse (Lepeophtheirus salmonis)

2011 ◽  
Vol 89 (9) ◽  
pp. 796-807 ◽  
Author(s):  
S. Tang ◽  
A.G. Lewis ◽  
M. Sackville ◽  
L. Nendick ◽  
C. DiBacco ◽  
...  
Keyword(s):  
Vertical Distribution ◽  
Water Column ◽  
Pink Salmon ◽  
Distribution Patterns ◽  
Oncorhynchus Gorbuscha ◽  
Lepeophtheirus Salmonis ◽  
Night Time ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Salmon Louse ◽  
Seawater Acclimation

We observed diel vertical migration patterns in juvenile pink salmon ( Oncorhynchus gorbuscha (Walbaum, 1792)) and tested the hypothesis that fish behaviour is altered by exposure to sea lice copepodids. Experiments involved replicated field deployments of a large (9 m) plankton column, which provided a vertical distribution enclosure under natural light and salinity conditions. Diel vertical distributions of juvenile pink salmon were observed during the first 3 weeks of seawater acclimation in both the presence and the absence of the ectoparasitic salmon louse ( Lepeophtheirus salmonis (Krøyer, 1838)). Immediately upon entering seawater, juvenile pink salmon preferred the top 1 m of the water column, but they moved significantly deeper down the vertical water column as seawater acclimation time increased. A significant diel migration pattern was observed, which involved a preference for the surface at night-time, compared with daytime. When fish in the column were exposed to L. salmonis copepodids for 3 h, 43%–62% of fish became infected, fish expanded their vertical distribution range, and significant changes in vertical distribution patterns were observed.

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.

scholarly journals Optimal estimation of catch by the continuous underway fish egg sampler based on a model of the vertical distribution of American plaice (Hippoglossoides platessoides) eggs

2006 ◽  
Vol 64 (1) ◽  
pp. 18-30 ◽  
Author(s):  
P. Pepin ◽  
K. A. Curtis ◽  
P. V. R. Snelgrove ◽  
B. de Young ◽  
J. A. Helbig
Keyword(s):  
Vertical Distribution ◽  
Water Column ◽  
Vertical Profile ◽  
Negative Binomial ◽  
Optimal Estimation ◽  
Eddy Diffusivity ◽  
Model Parameters ◽  
Error Structure ◽  
The Vertical Distribution ◽  
Hippoglossoides Platessoides

Abstract Pepin, P., Curtis, K.A., Snelgrove, P.V.R., de Young, B., and Helbig, J.A. 2007. Optimal estimation of catch by the continous underway fish egg sampler based on a model of the vertical distribution of American plaice (Hippoglossoides platessoides) eggs – ICES Journal of Marine Science, 64, 18–30. We investigate how the vertical stratification of the water column (specifically density) affects predictions of the catch of American plaice eggs (Hipploglossoides platessoides) from a fixed-depth sampler [the continuous underway fish egg sampler (CUFES)] relative to the integrated abundance in the water column measured in bongo tows. A steady-state model of the vertical distribution of fish eggs coupled with a simple model of the vertical profile of eddy diffusivity (i.e. mixing) is applied. Key model parameters are estimated through optimization of a one-to-one relationship between predicted and observed catches fit, using a generalized linear model with a Poisson, negative binomial, or gamma error structure. The incorporation of data on the vertical structure of the water column significantly improved the ability to forecast CUFES catches when using Poisson or negative binomial error structure, but not using a gamma distribution. Optimal maximum likelihood parameter estimates for eddy diffusivity and egg buoyancy fell within the range of expected values. The degree of uncertainty in the parameterization of eddy diffusivity suggests, however, that greater understanding of the forces that determine the vertical profile of mixing is critical to achieving strong predictive capabilities. The inverse problem of predicting integrated abundance from CUFES catches did not benefit from the environmental-driven model because of the high uncertainty in the catches from the CUFES.

Population dynamics and feeding ecology of juvenile Australian salmon (Arripis trutta) in Westren Port, Victoria

1982 ◽  
Vol 33 (2) ◽  
pp. 369 ◽  
Author(s):  
AI Robertson
Keyword(s):  
Population Dynamics ◽  
Water Column ◽  
Feeding Ecology ◽  
Age Group ◽  
Gill Raker

Juveniles (0 + age group) of both subspecies of the Australian salmon were captured over eelgrass meadows in Western Port at various times between October 1974 and February 1976. The western subspecies and the eastern subspecies were present from August through April, and December through May, respectively. The western subspecies always fed on benthic-dwelling prey including fishes, crabs and shrimps, and the eastern subspecies fed on prey which inhabited the water column (crustacean larvae, insects and epitokous polychaetes) in December but switched to benthic-dwelling prey (fishes, small squid, benthic crustaceans and polychaetes) in May. The role of different gill-raker number and morphology in effecting dietary separation of the subspecies is unclear.

scholarly journals Vertical Distribution of Microplastics in the Water Column and Surficial Sediment from the Milwaukee River Basin to Lake Michigan

2019 ◽  
Vol 53 (21) ◽  
pp. 12227-12237 ◽  
Author(s):  
Peter L. Lenaker ◽  
Austin K. Baldwin ◽  
Steven R. Corsi ◽  
Sherri A. Mason ◽  
Paul C. Reneau ◽  
...  
Keyword(s):  
Vertical Distribution ◽  
Water Column ◽  
River Basin ◽  
Lake Michigan ◽  
Surficial Sediment
Sign in / Sign up

Export Citation Format

Share Document