Spatial distribution of Atlantic salmon (Salmo salar) breeders: among- and within-river variation and predicted consequences for offspring habitat availability

2010 ◽  
Vol 67 (12) ◽  
pp. 1993-2001 ◽  
Author(s):  
Anders Gravbrøt Finstad ◽  
Sigurd Einum ◽  
Leif Magnus Sættem ◽  
Bjart Are Hellen
Keyword(s):  
Spatial Distribution ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Early Life ◽  
Skewed Distribution ◽  
Habitat Availability ◽  
Life Stages ◽  
Early Life Stages ◽  
Juvenile Dispersal ◽  
Atlantic Salmon Salmo Salar

The spatial distribution of breeders within populations may have important implications for offspring habitat availability in species where mobility of early life stages is restricted. Here we address this issue using time series of spawner distributions from eight Norwegian Atlantic salmon ( Salmo salar ) populations. Whereas spawners distribute themselves uniformly along the length of the rivers in some populations, others show a heavily skewed distribution. Linear mixed models identified pronounced and temporally consistent among-population differences in spawner distributions. Using a model of limited juvenile dispersal from nests following emergence, we show that the observed spawner distributions are predicted to result in significant proportions of rivers being inaccessible for young of the year during early life stages, and the magnitude of this effect differs among populations (e.g., ranging from 27% to 59% for dispersal distance of 250 m). Thus, assuming population regulation during early but not later juvenile stages, consistent differences in spawner distributions among populations such as those observed here may translate into differences in productivity (i.e., carrying capacity) as well as egg densities required for populations to reach their spawning targets.

Distribution of Al, Cd, Cu, Fe, Mn, Pb and Zn in Liver, Gills and Muscle of Early Life Stages of Atlantic Salmon (Salmo salar)

2019 ◽  
Vol 102 (3) ◽  
pp. 419-424
Author(s):  
María Gabriela Lobos ◽  
Claudio Sáez ◽  
Alejandra Chavarría ◽  
Maritza Sepúlveda ◽  
Patricia Díaz ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Early Life ◽  
Life Stages ◽  
Early Life Stages ◽  
Atlantic Salmon Salmo Salar

Influence of environmental conditions on spatial distribution and abundance of early life stages of Antarctic silverfish,Pleuragramma antarcticum(Nototheniidae), in the Ross Sea

2010 ◽  
Vol 22 (3) ◽  
pp. 243-254 ◽  
Author(s):  
Mario La Mesa ◽  
Barbara Catalano ◽  
Aniello Russo ◽  
Silvio Greco ◽  
Marino Vacchi ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Early Life ◽  
General Circulation ◽  
Ross Sea ◽  
Life Stages ◽  
Early Life Stages ◽  
Pleuragramma Antarcticum ◽  
Antarctic Silverfish ◽  
The Antarctic ◽  
Western Ross Sea

AbstractThe Antarctic silverfishPleuragramma antarcticumBoulenger is the dominant fish species in the high Antarctic zone, playing a key role in the Ross Sea midwater shelf ecosystem. Unlike other notothenioids, it is holoplanktonic species, spending its entire life cycle in the water column. Early life stages ofP. antarcticumare generally found in the upper 200 m and their spatial distribution is largely affected by water masses and general circulation. To understand better the mechanisms involved in the geographical distribution of the Antarctic silverfish within the western Ross Sea, an analysis of abundance and distribution was carried out in relation to oceanographic conditions. Samples were collected in summer during the 1998, 2000 and 2004 Italian cruises, covering the majority of the western sector of the Ross Sea. Overall 127 stations were sampled using standard plankton nets for biological samples and CTD and XBT to record abiotic parameters. Although all surveys were in December–January, the yearly results differed in terms of relative abundance of larval developmental stages and of oceanographic characteristics. The 1997–98 samples were characterized by very low abundance overall and by the virtual absence of early larvae. In summers 1999–2000 and 2003–04 the abundance ofP. antarcticumwas one order of magnitude higher than in the earlier season. In 1999–2000 catches were mainly composed of pre-flexion larvae and late postlarvae, while in 2003–04 catches were made up of pre-flexion larvae and juveniles. In January 2000 the Ross Sea summer polynya was fully open as the pack ice was almost completely melted, whereas in January 1998 and 2004 the opening of the polynya was considerably delayed. As a consequence, a delay in phytoplankton blooms and a decrease in primary production were observed in the summer seasons 1998 and 2004 with respect to 2000. The spatial distribution of early life stages, that were confined to the continental shelf and shelf break of the Ross Sea, generally appeared to be positively influenced by transition zones (oceanographic fronts). In addition, most of catches were recorded on or in close proximity to the banks (Pennell, Mawson, Ross and Crary) that characterize the continental shelf of the Ross Sea. On the basis of present findings and literature data, a link between the general circulation in the western Ross Sea and the distribution pattern of the early life stages ofP. antarcticumhas been developed.

Early life bacterial succession under different diet regime Atlantic salmon (Salmo salar L.)

2020 ◽  
Author(s):  
Eleni Nikouli ◽  
Konstantinos Kormas ◽  
Yang Jin ◽  
Yngvar Olsen ◽  
Ingrid Bakke ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Fish Oil ◽  
Early Life ◽  
Life Stages ◽  
Early Life Stages ◽  
Bacterial Phyla ◽  
Lipid Source ◽  
First Feeding ◽  
Bacterial Succession ◽  
Dietary Treatments

Abstract Backgound: The present study investigated the effect of different lipid source in the feed on the colonization and the bacterial succession in early life stages (fertilized eggs until 93 days post first feeding) of S. salar. The two diets used in this study, FD (fish oil based diet) and VD (vegetable oil based diet), were formulated to cover the fish nutritional requirements and except the lipid source the components were identical between them.Hindgut samples collected at 0, 35, 65 and 93 days post first feeding (dpff). Moreover, fertilized eggs, yolk sac larvae, rearing water and feed were also sampled in order to assess a possible contribution of their microbiota to the colonization of the gut. To analyze the composition of the bacterial communities, the Illumina MiSeq platform was used. Results: S. salar growth variables (mean wet weight and total length) did not differ significantly during the experiment (p> 0.05) across replicate tanks and between dietary treatments. The analysis of the 16S rDNA sequencing data revealed a total of 4548 unique OTUs, affiliated in 21 bacterial phyla. Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes were the dominant bacterial phyla. 13 OTUs were shared among all S. salar samples independent of life stage and diet treatment. Similarity percentages analysis (SIMPER) based on Bray–Curtis distance, showed that the average dissimilarity among the groups of the same life stages was 76.0%, whereas the average dissimilarity within groups of the same dietary treatment was 78.5% (FD) and 83.6% (VD). Conclusion: Feeding on either fish oil or vegetable oil-based diets, did not result in significant differences in the intestinal microbiota. The composition of gut microbiota did not differ significantly between the two dietary treatments, but changed with age, and each stage was characterized by different dominant bacteria. These OTUs are related to species that provide different functions and have been isolated from a variety of environments. Finally, this study revealed the occurrence of a core microbiota independent of the studied life stages and diet during the early life stages of Atlantic salmon.

Spatial diffusion modelling of juvenile Atlantic salmon (Salmo salar) shows ontogenetic increase in movement rates

2017 ◽  
Vol 74 (2) ◽  
pp. 202-207 ◽  
Author(s):  
A. Foldvik ◽  
S. Einum ◽  
A.G. Finstad
Keyword(s):  
Spatial Distribution ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Continuous Distribution ◽  
Diffusion Models ◽  
Ontogenetic Changes ◽  
Ecological Processes ◽  
Breeding Sites ◽  
Atlantic Salmon Salmo Salar ◽  
The Individual

For organisms with extensive ontogenetic changes in phenotypes, knowledge of how movement of individuals changes throughout life is pivotal to understanding ecological processes. Here, we study the spatial distribution of a cohort of Atlantic salmon (Salmo salar) from hatching to their third summer of juvenile life, during which they go through a fourfold change in body size. The fish originated from three distinct breeding sites, and their distribution was mapped using electrofishing throughout the river at 10 sampling periods. The spatial distribution throughout ontogeny was analysed using diffusion models. The distribution changed from three distinct nonoverlapping distributions centred on the individual breeding sites at the early first summer stage to a single continuous distribution at the end of the study. The diffusion coefficient increased throughout ontogeny, and spatial distributions were well-described using diffusion models, explaining 46%–89% of the variation. This highlights the utility of diffusion models when considering spatial habitat structure both in conservation and research.

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