A Model for Simulation of the Population Biology of Pacific Salmon

1964 ◽  
Vol 21 (5) ◽  
pp. 1245-1265 ◽  
Author(s):  
P. A. Larkin ◽  
A. S. Hourston
Keyword(s):  
Population Dynamics ◽  
Population Biology ◽  
Environmental Variability ◽  
Pacific Salmon ◽  
River System ◽  
Large River ◽  
Age At Maturity ◽  
Age Composition ◽  
Age Of Maturity ◽  
History Of

A model simulating the population dynamics of the stocks of salmon spawning in a large river system is constructed, incorporating (1) a series of theoretical reproduction curves operating in successive stages during the life history of each stock producing compensatory or depensatory effects, (2) a device for simulating environmental variability (extrapensatory effects), (3) the effects of a joint fishery on mixed stocks, (4) the effects of multiple age of spawning on fluctuation in abundance of a single stock, (5) the consequences to yield of various degrees of stabilization of the fishery, and (6) the inheritance of age at maturity in salmon. Application of the model is illustrated by two examples. The first simulates the production of cyclic dominance by the inheritance of age of maturity and depensation in the freshwater stage. In the second example, five stocks differing in relative abundance; age composition, environmental variability, and rate of compensation are subjected to a common fishery which is selective for age and provides for complete stabilization of the escapement for the combined run as a whole. Comparisons between various combinations of the five stocks show the effects of these factors on the various stocks and on the run as a whole over a simulated period of 120 years.

Metrics and sampling designs for detecting trends in the distribution of spawning Pacific salmon (Oncorhynchus spp.)

2012 ◽  
Vol 69 (4) ◽  
pp. 681-694 ◽  
Author(s):  
Stephanie J. Peacock ◽  
Carrie A. Holt
Keyword(s):  
Population Dynamics ◽  
Environmental Variability ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Oncorhynchus Kisutch ◽  
Sensitivity Analyses ◽  
Observation Error ◽  
Simulated Population ◽  
Age At Maturity ◽  
Status Assessment

The distribution of individuals among populations and in space may contribute to their resilience under environmental variability. Changes in distribution may indicate the loss of genetically distinct subpopulations, the deterioration of habitat capacity, or both. The distribution of Pacific salmon ( Oncorhynchus  spp.) among spawning locations has recently been recognized as an important component of status assessment by USA and Canadian management agencies, but metrics of spawning distribution have not been rigorously evaluated. We evaluated three metrics of spawning distribution and four sampling designs for their ability to detect simulated contractions in the production of coho salmon ( Oncorhynchus kisutch ). We simulated population dynamics at 100 sites using a spawner–recruit model that incorporated natural variability in recruitment, age-at-maturity, dispersal, and measurement error in observations of abundance. Sensitivity analyses revealed that high observation error and straying of spawners from their natal streams may mask changes in distribution. Furthermore, monitoring only sites with high spawner abundance, as is often practiced, failed to capture the simulated contraction of production, emphasizing the importance of matching monitoring programs with assessment objectives.

scholarly journals Neotectonic evolution and sediment budget of the Meuse catchment in the Ardennes and the Roer Valley Rift System

2002 ◽  
Vol 81 (2) ◽  
pp. 211-215 ◽  
Author(s):  
R.T. Van Balen ◽  
R.F. Houtgast ◽  
F.M. Van der Wateren ◽  
J. Vandenberghe
Keyword(s):  
Digital Terrain Model ◽  
River System ◽  
Sediment Budget ◽  
Middle Pleistocene ◽  
Rift System ◽  
Terrain Model ◽  
Fluvial Terraces ◽  
Digital Terrain ◽  
History Of ◽  
Planation Surfaces

AbstractUsing marine planation surfaces, fluvial terraces and a digital terrain model, the amount of eroded rock volume versus time for the Meuse catchment has been computed. A comparison of the amount of eroded volume with the volume of sediment preserved in the Roer Valley Rift System shows that 12% of the eroded volume is trapped in this rift. The neotectonic uplift evolution of the Ardennes is inferred from the incision history of the Meuse River system and compared to the subsidence characteristics of the Roer Valley Rift System. Both areas are characterized by an early Middle Pleistocene uplift event.

scholarly journals The Isotope Hydrology of a Large River System Regulated for Hydropower

2014 ◽  
Vol 31 (3) ◽  
pp. 335-349 ◽  
Author(s):  
C. Soulsby ◽  
C. Birkel ◽  
J. Geris ◽  
D. Tetzlaff
Keyword(s):  
River System ◽  
Large River ◽  
Isotope Hydrology

New Zealand translocations: theory and practice

1995 ◽  
Vol 2 (1) ◽  
pp. 39 ◽  
Author(s):  
Doug P. Armstong ◽  
Ian G. McLean
Keyword(s):  
Population Dynamics ◽  
New Zealand ◽  
Experimental Tests ◽  
Theory And Practice ◽  
Habitat Requirements ◽  
Metapopulation Dynamics ◽  
Behavioural Adaptation ◽  
New Locations ◽  
History Of ◽  
Tests Of Hypotheses

One of the most common tools in New Zealand conservation is to translocate species to new locations. There have now been over 400 translocations done for conservation reasons, mainly involving terrestrial birds. Most translocations have been done strictly as management exercises, with little or no reference to theory. Nevertheless, translocations always involve some underlying theory, given that people must inevitably choose among a range of potential translocation strategies. We review theory relevant to translocations in the following areas: habitat requirements, susceptibility to predation, behavioural adaptation, population dynamics, genetics, metapopulation dynamics, and community ecology. For each area we review and evaluate the models that seem to underpin translocation strategies used in New Zealand. We report experiments testing some of these models, but note that theory underlying translocation strategies is largely untested despite a long history of translocations. We conclude by suggesting key areas for research, both theoretical and empirical. We particularly recommend that translocations be designed as experimental tests of hypotheses whenever possible.

James C. Knox (1977) Human impacts on Wisconsin stream channels. Annals of the Association of American Geographers 67: 224–244.

2013 ◽  
Vol 37 (3) ◽  
pp. 422-431 ◽  
Author(s):  
William L. Graf
Keyword(s):  
Mississippi River ◽  
Human Impacts ◽  
Professional Community ◽  
River System ◽  
Stream Channels ◽  
Early 19Th Century ◽  
Driftless Area ◽  
University Of Wisconsin ◽  
History Of ◽  
Floodplain Deposits

James C. Knox’s 1977 paper “Human Impacts on Wisconsin Stream Channels,” published in the Annals of the Association of American Geographers, was a key component of a suite of three papers by him defining the response of rivers to the introduction and management of agriculture and to climate change. In this paper he used the Driftless Area of southwest Wisconsin as a laboratory where he could define fluvial responses by their sedimentary signatures in floodplain deposits. Land-use records dating back to the early 19th century along with shorter climate records provided his understanding of the drivers of change. He found that floods increased as an outcome of land-cover change. Upstream tributaries became wider and shallower as coarse deposits limited their adjustments, while main stem channels became narrower and deeper. His paper reflected the influence of his graduate advisor and especially of prominent faculty colleagues at the University of Wisconsin from fields ranging from soils and climatology to geomorphology and history. The paper was the subject of considerable debate in the professional community, but it remains a much-cited example of Knox’s work in unraveling the Quaternary and Holocene history of rivers of the Driftless Area and by extension the upper Mississippi River system.

Population dynamics of Stenothoe valida Dana, 1852 (Amphipoda, Stenothoidae) at Cheongsapo beach of Busan, Republic of Korea

Crustaceana ◽  
2021 ◽  
Vol 94 (4) ◽  
pp. 413-429
Author(s):  
Ye Ji Lee ◽  
Won Gyu Park
Keyword(s):  
Population Dynamics ◽  
Life History ◽  
Sex Ratio ◽  
Brood Size ◽  
Ovigerous Female ◽  
Seasonal Pattern ◽  
Recruitment Rate ◽  
Republic Of Korea ◽  
Female Size ◽  
History Of

Abstract The population dynamics of Stenothoe valida Dana, 1852 were studied at Cheongsapo beach of Busan, Republic of Korea, from March 2019 to March 2020. Sampling was conducted once a month at low tide during spring tides. Specimens were grouped by the cephalic length at 0.025 mm intervals, and classified into four categories: females, ovigerous females, males and juveniles. The sex ratio, defined as females : total males + females, exceeded 0.5 during most of the study period. Brood size was significantly coupled with ovigerous female size. Two to four cohorts appeared at each study period. New cohorts occurred at almost every sampling except in the samples Jun-2, and Nov-2. Life span was estimated at 1-2 months. The juvenile ratio, the ratio of ovigerous females, and the recruitment rate estimated by FiSAT were commonly high in summer and winter. The life history of S. valida was not coupled with water temperature, but had a strong seasonal pattern.

The evolutionary history of the goby Elacatinus puncticulatus in the tropical eastern pacific: Effects of habitat discontinuities and local environmental variability

2019 ◽  
Vol 130 ◽  
pp. 269-285 ◽  
Author(s):  
E.R. Sandoval-Huerta ◽  
R.G. Beltrán-López ◽  
C.R. Pedraza-Marrón ◽  
M.A. Paz-Velásquez ◽  
A. Angulo ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Environmental Variability ◽  
Eastern Pacific ◽  
Tropical Eastern Pacific ◽  
History Of

A comparison of modeling techniques to predict juvenile 0+ fish species occurrences in a large river system

2011 ◽  
Vol 6 (5) ◽  
pp. 276-285 ◽  
Author(s):  
J. Leclere ◽  
T. Oberdorff ◽  
J. Belliard ◽  
F. Leprieur
Keyword(s):  
Fish Species ◽  
River System ◽  
Large River ◽  
Modeling Techniques ◽  
Species Occurrences

scholarly journals Effects of Weir Construction on Phytoplankton Assemblages and Water Quality in a Large River System

2018 ◽  
Vol 15 (11) ◽  
pp. 2348 ◽  
Author(s):  
Hae-Jin Lee ◽  
Hae-Kyung Park ◽  
Se-Uk Cheon
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
River System ◽  
Large River ◽  
Anthropogenic Factors ◽  
Centric Diatom ◽  
Nakdong River ◽  
Biological Variables ◽  
Physical Chemical ◽  
The Nakdong River

Flow regulation is one of the most common anthropogenic factors affecting rivers worldwide. In Korea, 16 weirs were constructed along four major rivers from 2009 to 2012. This study aimed to elucidate initial changes in physical, chemical, and biological variables after the construction of consecutive weirs on the Nakdong River, a major large river system. Water quality variables and phytoplankton cell densities were investigated at eight representative sites and compared with the data recorded before the weir construction. There were spatial and temporal changes in the hydraulic retention time (HRT), total phosphorus (TP), and chlorophyll a concentrations among the eight weir sections. HRT increased after the weir construction, while TP and chlorophyll a tended to decrease from the middle to lower section of the Nakdong River. Furthermore, differences were observed in the phytoplankton community composition between 2006–2007 and 2013. There was a marginal decrease in the duration of centric diatom (Stephanodiscus hantzschii) blooms after weir construction. However, Microcystis aeruginosa proliferated more extensively during summer and autumn than it did before the weir construction. Our results suggest that changes in hydrological factors, in response to consecutive weir construction, may contribute to greater physical, chemical, and ecological variability.

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