Simulation Model of English Sole (Parophrys vetulus) Population Dynamics in Washington and Oregon Coastal Waters

1987 ◽  
Vol 44 (11) ◽  
pp. 1870-1878 ◽  
Author(s):  
Randall M. Peterman ◽  
Michael J. Bradford ◽  
Gordon H. Kruse
Keyword(s):  
Population Dynamics ◽  
Simulation Model ◽  
Larval Mortality ◽  
Early Life History ◽  
Fish Growth ◽  
English Sole ◽  
Egg Hatching ◽  
Density Dependent ◽  
Historical Variation ◽  
Parophrys Vetulus

We constructed an empirically based simulation model of population dynamics for English sole (Parophrys vetulus) occupying waters off the Washington and Oregon coast. While the original purpose for developing this model was to provide a tool for analysis of management questions, we also found it useful in evaluating hypotheses about biological processes in the early life history of sole. By comparing the ability of alternative sets of model hypotheses to reflect historical variation in abundance of age 4 recruits, we found some combinations of hypothesized mechanisms to be better than others. Approximately 61% of the interannual variation in recruitment was accounted for by a model which included (1) the effect of ocean temperatures on spawning timing, egg hatching, and fish growth, (2) density-dependent larval mortality, (3) age-dependent mortality of fish younger than age 4 yr, and (4) density-dependent growth of age 1 fish. This model explained more variation in recruitment than previous models of this population and emphasized the importance of timing of spawning on the subsequent abundance of the cohort.

Density-Dependent Growth of Age 1 English Sole (Parophrys vetuls) in Oregon and Washington Coastal Waters

1987 ◽  
Vol 44 (1) ◽  
pp. 48-53 ◽  
Author(s):  
Randall M. Peterman ◽  
Michael J. Bradford
Keyword(s):  
Coastal Waters ◽  
Time Trends ◽  
Annual Growth Rate ◽  
English Sole ◽  
Density Dependent ◽  
Stock Assessments ◽  
Negative Effect ◽  
Dependent Growth ◽  
Parophrys Vetulus ◽  
The Impact

We tested whether English sole (Parophrys vetulus) in Oregon and Washington waters show density-dependent growth. We found that there is a significant negative effect of cohort abundance on annual growth rate of age 1 fish, but not on growth of ages 2–7. Unlike most similar studies of density dependence, this result was not confounded by time trends in abundance and growth. The multiple regression of age 1 growth on cohort abundance and temperature accounted for 91% of the interannual variation in growth, which was a significant increase in r2 over that of the previously published relation with temperature alone. However, stock assessments which take into account only the previously published temperature effect on growth for this stock will probably not seriously overestimate the impact of management regulations which increase cohort abundance.

Bioavailability of Crude Oil from Experimentally Oiled Sediments to English Sole (Parophrys vetulus), and Pathological Consequences

1978 ◽  
Vol 35 (5) ◽  
pp. 657-664 ◽  
Author(s):  
B. B. McCain ◽  
H. O. Hodgins ◽  
W. D. Gronlund ◽  
J. W. Hawkes ◽  
D. W. Brown ◽  
...  
Keyword(s):  
Aromatic Hydrocarbon ◽  
Crude Oil ◽  
Petroleum Hydrocarbons ◽  
Dry Weight ◽  
Fish Growth ◽  
Continuous Exposure ◽  
English Sole ◽  
Initial Exposure ◽  
Aryl Hydrocarbon ◽  
Parophrys Vetulus

English sole (Parophrys vetulus) were exposed to experimentally oiled (Alaskan North Slope crude oil) sediments over a 4-mo period to assess the bioavailability and tissue hydrocarbon distribution kinetics in flatfish. Data were also obtained on hydrocarbon related physiological changes and tissue pathology. Crude oil was mixed with aromatic hydrocarbon-free sediments to a concentration of 700 μg/g dry weight at the beginning of the experiment. During the 1st mo of the experiment this concentration decreased to 400 μg/g dry weight, and remained relatively stable during the remainder of the 4-mo period. Compositional changes were observed in the alkane and aromatic fractions, with a differential decrease in the substituted naphthalenes. Flatfish maintained in such oiled sediments readily took up alkane and aromatic petroleum hydrocarbons from these sediments, and accumulated these in skin, muscle, and liver; 1- and 2-methylnaphthalene and 1,2,3,4-tetramethylbenzene were accumulated to greater extent than other aromatics. Tissue hydrocarbons decreased with time, and after 27-d continuous exposure to oiled sediments only the liver contained detectable levels of hydrocarbons. After 2 mo < 2% of the initial aromatic hydrocarbon load could be detected, and only in the liver in flatfish that were continuously maintained on oiled sediments. Depuration of tissue aromatics differed for various aromatics, 1,2,3,4-tetramethylbenzene and 2-methylnaphthalene being most persistent. Depuration is thought to be due to induction of the aryl hydrocarbon hydroxylase system during initial exposure to oiled sediments. Concomitant with the high tissue hydrocarbon period were found enhanced weight loss and severe hepatocellular lipid vacuolization (HLV). Although the observations, on growth changes and liver pathology are preliminary, the data indicate the need for further detailed study of fish growth abnormalities and pathology in the presence of petroleum hydrocarbons. Key words: flatfish, crude oil, bioavailability, pathology, aromatic hydrocarbons, bottom sediments, depuration

scholarly journals Effects of phenological synchronization on caterpillar early-instar survival under a changing climate

2018 ◽  
Vol 48 (3) ◽  
pp. 247-254 ◽  
Author(s):  
Emma Despland
Keyword(s):  
Population Dynamics ◽  
Host Plants ◽  
Larval Mortality ◽  
Mortality Rates ◽  
Chemical Defenses ◽  
Population Fluctuations ◽  
Density Dependent ◽  
Early Instar ◽  
Species Specific ◽  
Very High

Early-instar caterpillars experience very high and often very variable mortality; if it is density dependent, it can be a key factor in outbreak dynamics. Plant physical and chemical defenses can be extremely effective against young caterpillars, even of specialists. Phenological asynchrony with host plants can lead to dispersal and mortality in the early instars and increased predation or poor nutrition in later instars. Predation on early-instar larvae (including cannibalism) can be extremely high, parasitism appears generally low, and pathogens acquired early in larval development can lead to high mortality in later stadia. Four well-studied species reveal very different roles of early-instar mortality in population dynamics. In spruce budworm and gypsy moth, early-instar mortality rates can be very high; they do not drive outbreak cycles because density dependence is weak, but can modulate cycles and contribute to outbreak size and duration. For the autumnal moth, early-instar survival depends on host plant synchrony, but may or may not be density dependent. For monarch butterflies, the relative importance of larval mortality rates in population dynamics remains unclear. Tritrophic interactions between herbivores, host plants, natural enemies, and microbes play complex and species-specific roles in early-instar ecology, leading to emergent dynamics in population fluctuations. The phenology of these relationships is often poorly understood, making their responses to climate change unpredictable.

Simulation of Temperature and Upwelling Effects on the English Sole (Parophrys vetulus) Spawning Season

1983 ◽  
Vol 40 (2) ◽  
pp. 230-237 ◽  
Author(s):  
Gordon H. Kruse ◽  
Albert V. Tyler
Keyword(s):  
Simulation Model ◽  
Gonadal Development ◽  
Spawning Season ◽  
English Sole ◽  
Bottom Temperature ◽  
Temperature Index ◽  
Using Data ◽  
Parophrys Vetulus ◽  
Mathematical Relationships ◽  
Shelf Temperature

Spawning times for English sole (Parophrys vetulus) in Oregon waters were estimated for 13 yr using data on adult female gonadal condition, and surveys of pelagic larvae and benthic juveniles of known ages. The spawning season for this species is extremely protracted and variable. Some spawning may occur in all months, but most occurs between September and April, with a peak lasting 1–3 mo within this period. Variations in the English sole spawning season appear to be largely accountable by variations in a continental shelf temperature index (developed from a relationship with Neah Bay sea level). The following three hypotheses about temperature control of spawning were described by mathematical relationships which were incorporated into a simulation model that was driven by the time series of the bottom temperature index: (1) the rate of gonadal development is inversely related to summer bottom temperatures; (2) spawning is inhibited by temperatures below about 7.8 °C; and (3) spawning is delayed by rapid increases in bottom temperature. The model in its present form can be used to simulate spawning activity for years void of empirical spawning records and to design laboratory experiments capable of validating cause-and-effect relationships.Key words: Oregon, English sole, spawning time, upwelling, shelf temperature, hypotheses, simulation model

scholarly journals Effect of gallic acid on the larvae of Spodoptera litura and its parasitoid Bracon hebetor

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abhay Punia ◽  
Nalini Singh Chauhan ◽  
Drishtant Singh ◽  
Anup Kumar Kesavan ◽  
Sanehdeep Kaur ◽  
...  
Keyword(s):  
Gallic Acid ◽  
Spodoptera Litura ◽  
Negative Impact ◽  
Larval Mortality ◽  
Adult Emergence ◽  
Egg Hatching ◽  
Bracon Hebetor ◽  
Total Hemocyte Count ◽  
Glutathione S Transferases ◽  
Immense Potential

AbstractThe antibiosis effect of gallic acid on Spodoptera litura F. (Lepidoptera: Noctuidae) and its parasitoid evaluated by feeding six days old larvae on artificial diet incorporated with different concentrations (5 ppm, 25 ppm, 125 ppm, 625 ppm, 3125 ppm) of the phenolic compound revealed higher concentration (LC50) of gallic acid had a negative impact on the survival and physiology of S. litura and its parasitoid Bracon hebetor (Say) (Hymenoptera:Braconidae). The mortality of S. litura larvae was increased whereas adult emergence declined with increasing concentration of gallic acid. The developmental period was delayed significantly and all the nutritional indices were reduced significantly with increase in concentration. Higher concentration (LC50) of gallic acid adversely affected egg hatching, larval mortality, adult emergence and total development period of B. hebetor. At lower concentration (LC30) the effect on B. hebetor adults and larvae was non-significant with respect to control. Gene expression for the enzymes viz., Superoxide dismutase, Glutathione peroxidase, Peroxidase, Esterases and Glutathione S transferases increased while the total hemocyte count of S. litura larvae decreased with treatment. Our findings suggest that gallic acid even at lower concentration (LC30) can impair the growth of S. litura larvae without causing any significant harm to its parasitoid B. hebetor and has immense potential to be used as biopesticides.

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