Survival of pacific salmons in the North Pacific in winter-spring season

Influence of several factors (water temperature, food supply, predatory, size of juveniles) on pacific salmons survival during wintering is considered on the data collected from the upper pelagic layer in surveys conducted by Pacific Fisheries Research Center (TINRO) in the North-West Pacific. There is highly unlikely that the temperature influences on fish mortality directly. There is no obvious proof of negative influence of the low temperature on food base of salmons, as well. The lowering of forage zooplankton biomass in the Subarctic Front zone in February-March is insufficient for the salmons starvation taking into account that the total abundance of planktivorous nekton is also lowered in this area and generally in the Subarctic waters in winter-spring, so the food supply cannot be considered as a crucial factor of the salmons survival. Seasonal changes with lowering of feeding intensity, lipid accumulation, and somatic growth in winter known for pacific salmons aren’t forced by poor food base but are a feature of their species-specific life strategy with cyclic changes of metabolism. Predators are not abundant in the Subarctic zone in winter, so the predatory also cannot cause the high mortality of salmons. Relationship between the size of juveniles and their mortality in winter is considered in detail for the Okhotsk Sea stocks of pink salmon and there is concluded that the size of juveniles cannot be a predictor of their year-classes return for spawning. Thus, any single factor doesn’t determine winter mortality of pacific salmons but their survival is likely determined by a complex interaction of abiotic and biotic factors.

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Temporal patterns in distributions of tropical fish larvae on the North West Shelf of Australia

Marine and Freshwater Research ◽

10.1071/mf03160 ◽

2004 ◽

Vol 55 (5) ◽

pp. 473 ◽

Cited By ~ 21

Author(s):

A. Sampey ◽

M. G. Meekan ◽

J. H. Carleton ◽

A. D. McKinnon ◽

M. I. McCormick

Keyword(s):

Southern Oscillation ◽

Fish Larvae ◽

Early Stage ◽

Larval Survival ◽

Zooplankton Biomass ◽

Tropical Fish ◽

North West ◽

Larval Fishes ◽

The North ◽

Abundance And Diversity

Information on the temporal distributions of tropical fish larvae is scarce. Early stage larval fishes were sampled using towed bongo plankton nets at sites on the southern North West Shelf of Australia (21°49′S, 114°14′E), between October and February of 1997/98 and 1998/99. The first summer was characterised by El Niño–Southern Oscillation-driven upwelling and high primary productivity, whereas in the second summer water temperatures were warmer and primary production was lower. Benthic percoid shorefishes dominated surface assemblages in both summers and this pattern may be typical of tropical shelf environments.The abundance and diversity of larval fishes were lowest in October and increased from November through to February. Assemblages displayed weak cross-shelf patterns, with a few taxa being more abundant at inshore sites (e.g. monacanthids), whereas others were more abundant offshore (e.g. scombrids). Although the composition of assemblages remained relatively consistent, many taxa (e.g. pomacentrids and carangids) showed differences in abundance between summers. Multivariate analyses found no relationships between abundance patterns of larval fishes and biophysical variables, such as temperature, salinity, and zooplankton biomass. Thus, seasonal changes in abundance may reflect differences in the spawning activities of adult fishes and/or larval survival.

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Developments in Animal Husbandry and Food Supply in Roman Germania Inferior

European Journal of Archaeology ◽

10.1017/eaa.2016.31 ◽

2017 ◽

Vol 20 (3) ◽

pp. 451-471 ◽

Cited By ~ 2

Author(s):

Maaike Groot

Keyword(s):

Food Supply ◽

Animal Husbandry ◽

River Rhine ◽

North West ◽

The North ◽

The Subject ◽

Rural Sites ◽

Roman Province ◽

Species Proportions ◽

Over Time

The Roman province of Germania Inferior is characterized geographically by the river Rhine—the border of the Empire—and the forts along it. From the north-west to the south-east, there are significant differences in landscape and type of rural habitation. Whether these differences are also noticeable in animal husbandry forms the subject of this article. Are there any differences in species proportions and slaughter ages between the western and eastern parts of the province, and between urban, military, and rural sites? What does this say about farming and food supply? After presenting an overview of the zooarchaeological data from Germania Inferior, I shall discuss in detail one civitas—the civitas Batavorum, with the best known zooarchaeological dataset within the province. What changes in species proportions and cattle size can be detected over time from this civitas? Is there evidence for inter- and intra-site variability and changes in butchery methods? This article's further aim is to demonstrate what kind of questions a synthetic overview of zooarchaeological datasets can address.

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Reproductive biology, diet and feeding pattern of longtail tuna Thunnus tonggol (Bleeker, 1851) in the north-eastern Arabian Sea off Gujarat, India

Indian Journal of Fisheries ◽

10.21077/ijf.2018.65.2.78457-02 ◽

2018 ◽

Vol 65 ◽

Author(s):

K. Mohammed Koya ◽

Prathibha Rohit ◽

E. M. Abdussamad ◽

P. Abdul Azeez ◽

Vinay Kumar Vase ◽

...

Keyword(s):

Reproductive Biology ◽

West Coast ◽

Arabian Sea ◽

Feeding Intensity ◽

North West ◽

The North ◽

Northern Arabian Sea ◽

Male Preponderance ◽

Food And Feeding ◽

Longtail Tuna

Longtail tuna <em>Thunnus tonggol</em> (Bleeker, 1851) is the major tuna resource in the neritic realms of the northern Arabian Sea and forms considerable fishery in the coastal nations in the region. Gujarat, on the north-west coast is the major province landing longtail tuna in India. The paper attempts to add to the hitherto sparse knowledge base on biology of the longtail tuna fished along the north-west coast of India, through a study spanning from 2011 to 2015. Reproductive biology, spawning, food and feeding dynamisms of the species were investigated. Sex ratio of the species was estimated as 1:2.1 and depicted an increase in male preponderance as the size increased. The fish attains maturity at 607 mm and it spawns during summer months starting from May. The fish is typically a non-selective feeder and over 22 taxa comprising of fishes, cephalopods and crustaceans formed the diet at varying rates over the year. Variation in feeding intensity at different reproductive stages is discussed besides the constraint posed by the large presence of unidentifiable, partially digested gut content.

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Sustainable Careers: Reliability of Job Satisfaction Predictors for Employees Aged 50+. Evidence from Romanian Development Regions

Sustainability ◽

10.3390/su13158133 ◽

2021 ◽

Vol 13 (15) ◽

pp. 8133

Author(s):

Aurelian-Petruș Plopeanu ◽

Daniel Homocianu ◽

Ionel Bostan ◽

Ana-Iolanda Vodă ◽

Nelu Florea

Keyword(s):

Job Satisfaction ◽

Meaning In Life ◽

Career Satisfaction ◽

Negative Influence ◽

North West ◽

North East ◽

The North ◽

Work Family ◽

Average Marginal Effects ◽

Work Done

In this paper, we analyze the determinants of job satisfaction for employees over the age 50 or more, using the latest SHARE-ERIC dataset (Wave 7) filtered for Romania (over 2000 records). After applying logistic regressions with average marginal effects, we obtained an overall and seven regional models which emphasize that a good atmosphere at the workplace and the deserved recognition received for the work done are the most reliable predictors of career satisfaction, confirmed in this order of importance by many other robustness checks. Particularly, in the case of respondents from the Western part of Romania, we found that meritocracy-based influence, namely deserved recognition, counts almost as much as the workplace atmosphere. For these individuals, previous educational performance and lifetime employment at a single job matter more than the previous dual-core on job satisfaction. Unexpectedly, the adults from central romania present a negative influence of life satisfaction on job satisfaction due to an unbalanced work-family vision of life. The locus of control has different effects on job satisfaction in south and south-western regions, while in the north-east, meaning in life is negatively influencing job satisfaction. Bridge employment exerts a negative influence on career satisfaction in the north-west, and in the South-East, and interpersonal trust has a positive effect.

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Zooplankton Abundance in Australasian Waters

Marine and Freshwater Research ◽

10.1071/mf9620106 ◽

1962 ◽

Vol 13 (2) ◽

pp. 106 ◽

Cited By ~ 63

Author(s):

DJ Tranter

Keyword(s):

West Coast ◽

Zooplankton Biomass ◽

Open Ocean ◽

Zooplankton Abundance ◽

Sargasso Sea ◽

North West ◽

The North ◽

South Wales ◽

Tasman Sea ◽

Upwelling Area

The seas surrounding Australia contain a relatively low zooplankton biomass, particularly in the open ocean. There is a region of higher biomass in an upwelling area between the north-west coast of Australia and Indonesia, and there are indications that there may be a shortlived spring increase in the southern Tasman Sea; otherwise, the biomass of zooplankton in the open ocean is no higher than in the Sargasso Sea. An examination of values for other parts of the world reveals that subtropical regions of the open ocean are characteristically poor in plankton. The mean zooplankton biomass on the Australian continental shelf was estimated to be about 100 mg/m³ (exclusive of salp swarms), varying from 82 to 213 mg/m³ with the area and the year. The biomass in the upwelling area south of Java was of the same magnitude, but in most parts of the open ocean it was no greatsr than 50 mg/m³, and was usually less than 25 mg/m³. Salp swarms were found more commonly in the southern part of the area investigated, and constituted local concentrations of higher biomass. These swarms took place in sprlng and summer and led to a seasonal cycle in the biomass level on the shelf regions of the New South Wales south coast. An increased biomass was also observed off the north-west coast of Australia during the period of prevailing offshore winds. This was crustacean in character.

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The Danube legions of the Late Roman Empire (I Italica and V Macedonica) during the second half and middle of the fourth c. a. d.: on the ways of interaction between the frontier and expeditionary armies

Scientific bulletins of the Belgorod State University Series History Political science ◽

10.18413/2075-4458-2019-46-4-608-619 ◽

2019 ◽

Vol 46 (4) ◽

pp. 608-619

Author(s):

Е.А. Mekhamadiev ◽

Keyword(s):

Roman Empire ◽

Food Supply ◽

Near East ◽

Asia Minor ◽

North West ◽

The North ◽

Roman Provinces ◽

Military Campaigns ◽

Military Units ◽

Late Roman

Since 325 A. D., when the Emperor Constantine the Great established a self-sufficient and single expeditionary army of the Roman Empire (previously, before 353, it constantly had stood in Thrace, but then it was split in some smaller military groups), military units of this army have interacted to units of frontier armies during many military campaigns. But epigraphic data from the Lower Danube regions (the provinces of Lower Moesia and Dacia Ripensis (River)) give a chance to trace one another way of interaction, which was an absolutely disregarded before. The author means a food supply of frontier units from the provinces where the expeditionary troops (or imperial bodyguards) had their service. The inscriptions covered by this paper contain evidence about two important Danube frontier legions, that are I Italica (Lower Moesia) and V Macedonica (Dacia Ripensis (River)), which received a food from the Roman Near East provinces (the author means Hellespontus at the North-West of the Asia Minor and Syria Foenice and Syria Palestina just at the Persian frontier), but not from the Danube regions. As the author supposes, the reason of such a way of supply was that some military units (vexillations) detached from the staff of the Danube frontier legions served within the Near East Roman provinces, these vexillations moved at the Near East during the time of the Tetrarchy (293–324) or the sole reign of Constantine the Great (324–337). After their relocation to the Near East, vexillations of the Danube frontier legions have never returned in their home Danube provinces, in contrast, they were parts of the Near East expeditionary armies. But, as a matter of award for diminishing of their staff, the Danube frontier («maternal») legions received a food from the provinces, where their «child» vexillations located and served.

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SEM and TEM observations of sperm development in the testis of the freshwater fish Oreochromis mossambicus

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100157838 ◽

1990 ◽

Vol 48 (3) ◽

pp. 58-59

Author(s):

Daryl A. Cornish ◽

George L. Smit

Keyword(s):

Morphological Characteristics ◽

Oreochromis Mossambicus ◽

Breeding Cycle ◽

Limited Information ◽

North West ◽

The North ◽

Sem And Tem ◽

Sperm Development ◽

Ultrastructural Characteristics ◽

The University

Oreochromis mossambicus is currently receiving much attention as a candidater species for aquaculture programs within Southern Africa. This has stimulated interest in its breeding cycle as well as the morphological characteristics of the gonads. Limited information is available on SEM and TEM observations of the male gonads. It is known that the testis of O. mossambicus is a paired, intra-abdominal structure of the lobular type, although further details of its characteristics are not known. Current investigations have shown that spermatids reach full maturity some two months after the female becomes gravid. Throughout the year, the testes contain spermatids at various stages of development although spermiogenesis appears to be maximal during November when spawning occurs. This paper describes the morphological and ultrastructural characteristics of the testes and spermatids.Specimens of this fish were collected at Syferkuil Dam, 8 km north- west of the University of the North over a twelve month period, sacrificed and the testes excised.

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