Migration patterns of barramundi, Lates calcarifer (Bloch), in Papua New Guinea

1982 ◽  
Vol 33 (4) ◽  
pp. 671 ◽  
Author(s):  
R Moore ◽  
LF Reynold
Keyword(s):  
Coastal Waters ◽  
Climatic Conditions ◽  
First Year ◽  
Inland Waters ◽  
Adult Fish ◽  
Age Classes ◽  
Lates Calcarifer ◽  
Spawning Grounds ◽  
Migration Patterns ◽  
Factors Affecting

Adult L. calcarifer released in inland waters migrated to coastal spawning grounds. and those released on the spawning grounds returned to inland areas. Of 6369 fish tagged throughout western Papua, 978 (15.4%) recaptures were recorded, the maximum distance between release and recapture being 622 km. Tag recoveries indicated that these adult fish return to the same general area from which they originally migrated. Juveniles leave coastal nursery swamps when about 6 months old and by the end of their first year have become distributed throughout coastal and estuarine regions. During their second or third year they move into inland waters. although there is a residual population of all age classes that remains resident in coastal waters. Some 3-year-old, and a significant number of 4-year-old, fish undertake the annual migration from inland to coastal waters. Prevailing climatic conditions appear to affect the magnitude of this migration as not all of the adult fish migrate to coastal waters every year. Factors affecting this migration are discussed.

Spawning and early life history of burramundi, Lates calcarifer (Bloch), in Papua New Guinea

1982 ◽  
Vol 33 (4) ◽  
pp. 647 ◽  
Author(s):  
R Moore
Keyword(s):  
Papua New Guinea ◽  
Coastal Waters ◽  
Early Life History ◽  
Lates Calcarifer ◽  
Spawning Grounds ◽  
Spawning Period ◽  
History Of ◽  
June July ◽  
Dry Out ◽  
The Relationship

L. calcarifer in western Papua is catadromous, undertaking substantial migrations to specific spawning grounds. The location and environmental characteristics of these spawning grounds and possible spawning stimuli are discussed. The annual spawning period extends from October to February but that for individual fish is relatively short. Fecundity (4 varies from 2.3 × 106 to 32.2 × 106 within the weight range 7.7-20.8 kg, being related to the total weight W (in kilograms) by the relationship F = 1.942 W × 106 - 13.816 × 106. The eggs, larvae and juveniles are described. Larvae leave coastal waters when approximately 5 mm long and enter coastal nursery swamps where they remain until they attain a length of 200-300 mm. They then return to coastal waters as the nursery swamps begin to dry out (June-July).

Impact of climatic conditions on the parameters of failure flow of military vehicles

2021 ◽  
pp. 095440702110202
Author(s):  
Nikolaj Dobrzinskij ◽  
Algimantas Fedaravicius ◽  
Kestutis Pilkauskas ◽  
Egidijus Slizys
Keyword(s):  
Climatic Factors ◽  
Armed Forces ◽  
Climatic Conditions ◽  
Operating Conditions ◽  
Technical Equipment ◽  
Factors Affecting ◽  
Military Vehicles ◽  
Equipment Reliability ◽  
Number Of Factors ◽  
The Impact

Relevance of the article is based on participation of armed forces in various operations and exercises, where reliability of machinery is one of the most important factors. Transportation of soldiers as well as completion of variety of tasks is ensured by properly functioning technical equipment. Reliability of military vehicles – armoured SISU E13TP Finnish built and HMMWV M1025 USA built were selected as the object of the article. Impact of climatic conditions on reliability of the vehicles exploited in southwestern part of the Atlantic continental forest area is researched by a case study of the vehicles exploitation under conditions of the climate of Lithuania. Reliability of military vehicles depends on a number of factors such as properties of the vehicles and external conditions of their operation. Their systems and mechanisms are influenced by a number of factors that cause different failures. Climatic conditions represent one of the factors of operating load which is directly dependent on the climate zone. Therefore, assessment of the reliability is started with the analysis of climatic factors affecting operating conditions of the vehicles. Relationship between the impact of climatic factors and failure flow of the vehicles is presented and discussed.

scholarly journals Estimation of Electricity Generation by an Electro-Technical Complex with Photoelectric Panels Using Statistical Methods

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1278
Author(s):  
Anna Turysheva ◽  
Irina Voytyuk ◽  
Daniel Guerra
Keyword(s):  
Random Distribution ◽  
Graphical Representation ◽  
Random Variable ◽  
Climatic Conditions ◽  
Characteristic Energy ◽  
Study Region ◽  
Factors Affecting ◽  
Solar Systems ◽  
The Republic ◽  
Technical Complex

This paper presents a computational tool for estimating energy generated by low-power photovoltaic systems based on the specific conditions of the study region since the characteristic energy equation can be obtained considering the main climatological factors affecting these systems in terms of the symmetry or skewness of the random distribution of the generated energy. Furthermore, this paper is aimed at determining any correlation that exists between meteorological variables with respect to the energy generated by 5-kW solar systems in the specific climatic conditions of the Republic of Cuba. The paper also presents the results of the influence of each climate factor on the distribution symmetry of the generated energy of the solar system. Studying symmetry in statistical models is important because they allow us to establish the degree of symmetry (or skewness), which is the probability distribution of a random variable, without having to make a graphical representation of it. Statistical skewness reports the degree to which observations are distributed evenly and proportionally above and below the center (highest) point of the distribution. In the case when the mentioned distribution is balanced, it is called symmetric.

scholarly journals The features of the coastal fronts in the Eastern Guangdong coastal waters during the downwelling-favorable wind period

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chaoyu Yang ◽  
Haibin Ye
Keyword(s):  
Coastal Waters ◽  
Meteorological Data ◽  
Pearson Correlation ◽  
Ocean Model ◽  
Ekman Pumping ◽  
Zonal Distribution ◽  
Factors Affecting ◽  
China Sea ◽  
Hybrid Coordinate Ocean Model ◽  
The Mean

AbstractA coastal front was detected in the eastern Guangdong (EGD) coastal waters during a downwelling-favorable wind period by using the diffuse attenuation coefficient at 490 nm (Kd(490)). Long-term satellite data, meteorological data and hydrographic data collected from 2003 to 2017 were jointly utilized to analyze the environmental factors affecting coastal fronts. The intensities of the coastal fronts were found to be associated with the downwelling intensity. The monthly mean Kd(490) anomalies in shallow coastal waters less than 25 m deep along the EGD coast and the monthly mean Ekman pumping velocities retrieved by the ERA5 dataset were negatively correlated, with a Pearson correlation of − 0.71. The fronts started in October, became weaker and gradually disappeared after January, extending southwestward from the southeastern coast of Guangdong Province to the Wanshan Archipelago in the South China Sea (SCS). The cross-frontal differences in the mean Kd(490) values could reach 3.7 m−1. Noticeable peaks were found in the meridional distribution of the mean Kd(490) values at 22.5°N and 22.2°N and in the zonal distribution of the mean Kd(490) values at 114.7°E and 114.4°E. The peaks tended to narrow as the latitude increased. The average coastal surface currents obtained from the global Hybrid Coordinate Ocean Model (HYCOM) showed that waters with high nutrient and sediment contents in the Fujian and Zhejiang coastal areas in the southern part of the East China Sea could flow into the SCS. The directions and lengths of the fronts were found to be associated with the flow advection.

The issue of assessment of efficiency of works on land reclamation fisheries in inland waters of Russia

2021 ◽  
pp. 8-20
Author(s):  
Andrey Dmitrievich Bykov ◽  
Svetlana Yuryevna Brazhnik
Keyword(s):  
Fish Species ◽  
Land Reclamation ◽  
Long Term Results ◽  
Predatory Fish ◽  
Federal State ◽  
Inland Waters ◽  
Ecological Group ◽  
Spawning Grounds ◽  
Commercial Fish

The article considers the issue of assessing the long-term results of work on fisheries reclamation in inland waters of fisheries significance in Russia, carried out by the branches of the Federal State Budgetary Institution “Glavrybvod” on the state task in terms of their effectiveness. The relationship between dredging and clearing of watercourse beds and the dynamics of the number of producers of semi-navigable and non-aquatic fish in these rivers during spawning migrations has not been established. With long-term mowing of wetland vegetation in the shallow waters of reservoirs, deltas of large rivers and estuaries, there is no increase in their commercial fish productivity. A number of examples show the opposite effect of this type of work, which leads to a local deterioration of the ecological state of these reservoirs. At the same time, the repeatedly proven method of combating higher aquatic vegetation in the reservoirs of the south of Russia in low water conditions as biomelioration, based on the introduction of fish, consumers of autotrophic products by regional branches of the Federal State Budgetary Institution “Glavrybvod” is practically not used. When installing artificial spawning grounds in the littoral zone of reservoirs, regular ichthyological monitoring of the effectiveness of spawning on them is not carried out. There are no reliable data confirming the significant positive impact of artificial spawning grounds on the population dynamics of commercial fish species of the limnophilic ecological group under conditions of significant spring water level depletion in Russian reservoirs. When catching predatory and low-value fish species in water bodies, legal obstacles arise due to the fact that the volume of seizure of predatory fish includes commercial objects for which the ODE is established annually and their catch is already carried out according to industrial quotas.

Age- and sex-related morphological and physiological differences influence escape capacity in House Sparrows (Passer domesticus)

2010 ◽  
Vol 88 (10) ◽  
pp. 1021-1031 ◽  
Author(s):  
L. De Neve ◽  
J. D. Ibañez-Alamo ◽  
M. Soler
Keyword(s):  
Escape Response ◽  
Passer Domesticus ◽  
First Year ◽  
Cell Mediated Immunity ◽  
Animal Performance ◽  
House Sparrows ◽  
Factors Affecting ◽  
Age Related ◽  
Animal Populations ◽  
Age And Sex

Sexual dimorphism and age-related differences are sources that contribute to morphologic and physiologic variation within animal populations. Measurement of animal performance may indicate whether this variation is functionally relevant. Our study aimed to experimentally test this statement in a captive population of House Sparrows ( Passer domesticus (L., 1758)) by examining age- and sex-related differences in escape response and its relationship to several morphological (tarsus, wing, tail lengths, and body mass) and physiological traits (cell-mediated immunity, natural antibodies, complement activity, hematocrit, and stress response). Escape response from a predator is considered a good variable to measure animal performance, because natural selection clearly favours individuals that avoid predators successfully. Our experimental design also aimed to standardize possible confounding factors affecting escape behaviour under natural conditions. We exposed sparrows to short episodes of high predation risk by simulating the attack of a predator and assumed that the capture order of individuals was related to their escape capacity. The optimal strategy was the immediate escape response for all individuals. We found that first-year males were the best escapers. In support of the hypothesis, juvenile males gathered a better optimum of several morphological and physiological characters that related to capture order.

scholarly journals Allocative efficiency and adoption of improved maize variety: A case of eastern hills of Nepal

2020 ◽  
Vol 3 (1) ◽  
pp. 148-159
Author(s):  
Tilak Katel ◽  
Bhishma Raj Dahal ◽  
Sandesh Bhatta
Keyword(s):  
Regression Model ◽  
Insect Pest ◽  
Allocative Efficiency ◽  
Climatic Conditions ◽  
Probit Regression ◽  
Maize Production ◽  
Factors Affecting ◽  
Face To Face ◽  
Maize Variety ◽  
Structured Questionnaire

Production and  profit from maize farming can be substantially increased by allocating resources efficiently and adopting improved maize variety. In this context, a study was undertaken to determine the allocative efficiency and factors affecting adoption of improved maize variety in Eastern hills of Nepal. Random sampling was conducted in eastern part of Khotang district namely, Halesi municipality and Diktel Rupakot Majuwagadi municipality during month of March 2019. Pretested semi-structured questionnaire was administered among 80 randomly selected farmers cultivating maize since last two years. Face to face interview was scheduled to obtain data. Cobb Douglas production function was used to determine allocative efficiency; probit regression model was launched to determine factors affecting adoption of improved maize variety.  Significant positive relation of cost of seed, planting, and weeding with income has suggested to increase expenditure on certified maize seed over own farm seed, line sowing over broadcasting, and weeding. The model revealed that increasing all the factors of production by 100% would result in increase in income by 71.83%. Furthermore, cultivating improved maize variety is more profitable than own farm seed. Probit regression model showed that, farmers who have received training, who were member of cooperatives and who have received high schooling were more likely to adopt open-pollinated improved maize variety. Unavailability of inputs (seed, fertilizer, and labor), insect pest attack and adverse climatic conditions were major constraint of maize farming. Therefore, it would be better to suggest maize producers to increase expenditure on seed; make maize field weed free and adopt line sowing method. In addition, providing training, increasing access over inputs and encouraging farmers towards cooperatives could be virtuous for sustainable maize production.

scholarly journals The influence of meteorological conditions on major quantitative and qualitative traits of buckwheat (Fagopyrum esculentum Moench)

2003 ◽  
Vol 48 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Radojka Maletic ◽  
Radosav Jevdjovic
Keyword(s):  
Precipitation Amount ◽  
Seed Mass ◽  
Climatic Conditions ◽  
Meteorological Conditions ◽  
First Year ◽  
Lower Mass ◽  
Second Year ◽  
Average Plant ◽  
Fagopyrum Esculentum Moench ◽  
Year 2000

The results of two-year investigations of buckwheat raised in agroecological conditions of South Banat (Pancevo) and West Serbia (Gorobilje) are presented in the paper. Based on the obtained investigation data, we confirm the hypothesis that buckwheat is a plant suited to more humid regions, since we have determined higher yield of the plant on locations with higher precipitation amount. During 1999, the yield of buckwheat was higher at the location in Pancevo and the next year at the location in Gorobilje. Also, in the year 2000, values of average plant height, number of seeds per plant and seed mass per plant were higher at the location in Gorobilje, whereas in the year 1999 (first year of investigation), which from the aspect of climatic conditions could be considered as optimal, plant yield and all other investigated parameters were better in case of buckwheat originating from the location in Pancevo. In the year 2000, in regard to the seed proportionally medium fractions were more present, which is, among other things, the result of the influence of higher precipitation amount. In regard to the exploitation value of the seed, better germination was registered for seed produced in 2000 (at both locations), although it had lower mass compared to the seed produced in 1999. Blossoming (blooming) in the first study year at both locations started 5 to 7 days earlier compared to the second year of investigations and lasted 5 to 8 days longer. On the other hand, in the second year of investigations at both locations harvesting started 10 to 12 days earlier compared to the previous year.

Factors affecting the study pace of first-year law students: in search of study counselling tools

2011 ◽  
Vol 36 (8) ◽  
pp. 911-922 ◽  
Author(s):  
Anne Haarala-Muhonen ◽  
Mirja Ruohoniemi ◽  
Sari Lindblom-Ylänne
Keyword(s):  
Law Students ◽  
First Year ◽  
Factors Affecting
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