scholarly journals Hydrographic variability in Icelandic waters during recent decades and related changes in distribution of some fish species

2012 ◽  
Vol 69 (5) ◽  
pp. 816-825 ◽  
Author(s):  
Héðinn Valdimarsson ◽  
Olafur S. Astthorsson ◽  
Jonbjorn Palsson
Keyword(s):  
Fish Species ◽  
Saline Water ◽  
Shelf Area ◽  
Seasonal Time Series ◽  
Shelf Seas ◽  
Commercial Species ◽  
Area North ◽  
First Time ◽  
Icelandic Waters

Abstract Valdimarsson, H., Astthorsson, O. S., and Palsson, J. 2012. Hydrographic variability in Icelandic waters during recent decades and related changes in distribution of some fish species. – ICES Journal of Marine Science, 69: 816–825. Seasonal time-series of temperature and salinity around Iceland have been collected, with repeat observations at stations, since the start of the 1970s. After fairly cold years during the early 1990s, a reversal occurred during the mid-1990s and the period from 1996 to 2010 was one with warmer, more saline water in shelf seas around Iceland. Temperatures and salinities have been frequently above the long-term mean in the waters to the south and west of the country, and these conditions have also influenced the shelf area north of the country. Marked changes have also been observed in the distribution of many fish species during this warm period. Southern commercial species have extended farther north (e.g. haddock, monkfish, mackerel), a northern species is retreating (capelin), rare species and vagrants have been observed more frequently (e.g. greater fork beard, blue antimora, snake pipefish, sea lamprey, Ray's bream), and 31 species, from both shelf and oceanic waters, have been recorded for the first time since 1996. The most obvious explanation for these changes in the ecosystem has to be the warming of 1–2°C in the waters south and west of Iceland during the past 15 years.

scholarly journals Long-Term Trends in the Structure and Dynamics of the Fish Communities in Buško Blato Reservoir

2020 ◽  
Vol 78 (2) ◽  
pp. 69-78
Author(s):  
Aldijana Mušović ◽  
Rifat Škrijelj ◽  
Mahir Gajević ◽  
Belma Kalamujić Stroil ◽  
Adi Vesnić ◽  
...  
Keyword(s):  
Fish Species ◽  
Ecological Factors ◽  
Lepomis Gibbosus ◽  
Tinca Tinca ◽  
Structure And Dynamics ◽  
Current State ◽  
Long Term Trends ◽  
Endemic Fish ◽  
First Time

AbstractBuško Blato Reservoir, the third largest hydro accumulation in Europe, is situated in the south-eastern part of the karstic Livanjsko Polje Valley. This aquatic ecosystem is distinguished by a very rich ichthyofauna and the presence of four endemic fish species. Numerous studies focus on ichthyological researches of Buško Blato Reservoir. Its ichthyofauna has been exposed to changes in ecological factors, which in turn reflected on the structure and composition of fish populations. The main objective of this paper was to assess the current state and predict future trends in the ichthyofauna structure and dynamics based on the field data and comprehensive analyses of literature data. The results of the research indicated the presence of 11 fish species from four families, which is the largest number of fish species ever recorded in this ecosystem. Sander lucioperca, Lepomis gibbosus, Pseudorasbora parva and Tinca tinca were recorded for the first time in this ecosystem, while some previously recorded species were not found. The results of the analyses clearly indicate the presence of natural interspecific competition and significant level of threats to the endemic fish species caused by human activities.

scholarly journals Characterization of the Fish Population in the Southwestern Part of the Onega Lake (Karelia) Based on the Results of Long-Term Monitoring

2020 ◽  
Vol 8 (4) ◽  
pp. 1510-1515
Keyword(s):  
Fish Species ◽  
Fish Habitat ◽  
Fish Population ◽  
The Arctic ◽  
Coregonus Lavaretus ◽  
Southwestern Part ◽  
Onega Lake ◽  
Late Tertiary ◽  
Commercial Species

The results of the long-term ichthyological studies of the southwestern part (the Sheltozero – Brusno region) of the Onega Lake performed as part of the environmental monitoring have been presented. This is one of the most productive and clean areas in the lake. The fish population of the southwestern part of the Onega Lake includes 20 fish species that are representatives of 10 families belonging to six faunistic complexes. By the number of the species, the Carp family dominates. By the number of the species in this area of the lake, the Arctic freshwater, the boreal plain, and the boreal foothill complexes are equally important. The species of the freshwater Pontian, the Arctic marine, and the ancient Late Tertiary complexes together amount to no more than 25 % of the total population. In the southwestern region of the lake, there are many valuable commercial species (freshwater salmon (Salmo salar Linnaeus, 1758), lavaret (Coregonus lavaretus lavaretus (Linnaeus, 1758)), pikeperch (Sander lucioperca (Linnaeus, 1758)), pike (Esox lucius Linnaeus, 1758), etc. Smelt (Osmerus eperlanus (Linnaeus, 1758)) and vendace (Coregonus albula (Linnaeus, 1758)) are the most commercially valuable (75 – 85 %). The population-ecological analysis has shown a relatively good state of most studied fish species. For maintaining the existing structure and state of the fish population in the southwestern part of the Onega Lake, a set of measures is required, including the preservation and improvement of the fish habitat, the conditions for the fish reproduction and feeding; toughening the protective measures during periods with a decrease in the number of fish species; regulation of fishing, and increasing the amount of fish artificial reproduction, rearing, and releasing into the lake.

scholarly journals Fishes from Lachuá Lake, Upper Usumacinta Basin, Guatemala

Check List ◽  
2012 ◽  
Vol 8 (1) ◽  
pp. 095 ◽  
Author(s):  
Pablo Granados-Dieseldorff ◽  
Mäds F. Christensen ◽  
P. Herman Kihn-Pineda
Keyword(s):  
Fish Species ◽  
Fish Assemblages ◽  
Drainage Basin ◽  
Management Strategies ◽  
Hierarchical Cluster ◽  
Maya Lowlands ◽  
Visitor Center ◽  
Gobiomorus Dormitor ◽  
First Time

Guatemala’s Maya Lowlands constitute one of the most biodiverse regions in Mesoamerica and include 35% of the total number of continental fish species estimated for the nation. From May 2000 through February 2001, we conducted the first long-term ichthyological survey of Lachuá Lake, a 4 km2, 195 m deep, karstic sinkhole located in the middle of Guatemala’s Laguna Lachuá National Park (LLNP), southern Maya Lowlands. Thirty-six native fish species were identified and Gobiomorus dormitor Lacepède, 1800 was collected for the first time in northern Guatemala. Greater number of species occurred in the rocky shore of the lake’s littoral zone, especially around the mouths of Lachuá’s tributary and effluent rivers, and close to the visitor center of LLNP. A hierarchical cluster analysis for classifying ichthyogeographically regional fish assemblages placed Lachuá Lake in the upper Usumacinta River drainage basin shared by Guatemala and Mexico, stressing the need for regional conservation and management strategies.

Ecological hypotheses for a historical reconstruction of upper trophic level biomass in the Baltic Sea and Skagerrak

2002 ◽  
Vol 59 (1) ◽  
pp. 173-190 ◽  
Author(s):  
Brian R MacKenzie ◽  
Jürgen Alheit ◽  
Daniel J Conley ◽  
Poul Holm ◽  
Carl Christian Kinze
Keyword(s):  
Baltic Sea ◽  
Fish Species ◽  
Marine Mammal ◽  
Marine Mammals ◽  
Environmental Variability ◽  
Saline Water ◽  
Clupea Harengus ◽  
The Baltic Sea ◽  
The Baltic

Fish and marine mammal populations in the Baltic Sea and Skagerrak have undergone major fluctuations over the past five centuries. We summarize how these fluctuations may have depended on various forms of predation (e.g., cannibalism, fishing, hunting) and environmental processes. The best-documented long-term fisheries in this region are the herring (Clupea harengus) fisheries near Bohuslän, western Sweden, and in the Øresund. These fisheries have been important since at least the 1200s and appear to be partly climatically driven. However, in the rest of the Baltic, information about fisheries for herring and other fish species is rare until after 1900. During the 20th century, while the Baltic underwent eutrophication, the biomass and landings of three fish species (cod (Gadus morhua), herring, and sprat (Sprattus sprattus)) all increased, whereas the biomass of marine mammals (grey seals (Halichoerus grypus), ringed seals (Phoca hispida), harbour porpoises (Phocoena phocoena)) decreased. The relative roles of exploitation, marine mammal predation, and environmental variability (e.g., eutrophication, major inflows of saline water, climate change) on the long-term dynamics of key fish species is not clear and requires increased collaboration among historians, fisheries and marine mammal ecologists, oceanographers, and climatologists.

scholarly journals The use of otolith chemistry to determine the juvenile source of spawning cod in Icelandic waters

2010 ◽  
Vol 68 (1) ◽  
pp. 98-106 ◽  
Author(s):  
Konrad Thorisson ◽  
Ingibjörg G. Jónsdóttir ◽  
Gudrun Marteinsdottir ◽  
Steven E. Campana
Keyword(s):  
Gadus Morhua ◽  
North Coast ◽  
Otolith Chemistry ◽  
Shelf Area ◽  
The North ◽  
Chemical Fingerprinting ◽  
High Current Velocity ◽  
Area North ◽  
Mixed Stock ◽  
Icelandic Waters

Abstract Thorisson, K., Jónsdóttir, I. G., Marteinsdottir, G., and Campana, S. E. 2011. The use of otolith chemistry to determine the juvenile source of spawning cod in Icelandic waters. – ICES Journal of Marine Science, 68: 98–106. Chemical fingerprinting was used to discriminate spatial groups of juvenile cod (Gadus morhua) and to backtrack spawning cod in Icelandic waters to their area of origin as 0-group juveniles. Juvenile 0-group cod were collected around Iceland in August 1996 and 1997 to establish the spatial distribution of otolith chemistry at the juvenile stage. Spawning cod from the same year classes were sampled in the same areas in April 2002 and April/May 2003. The core, corresponding to the juvenile otolith, was extracted from the adult otolith and its content of Ba, Mn, and Sr compared with the chemistry of whole otoliths of juveniles of the same year class. High Atlantic inflow into the shelf area north of Iceland in 1997 mixed the juveniles from different areas, and the spawners of that year class were not backtraceable to their origin. For the 1996 year class, however, mixed-stock analysis indicated that most of the spawning cod northwest, north, and northeast of Iceland originated from juveniles off the central part of the north coast. Using otolith chemistry to backtrace the origin of spawners appears well suited for areas with limited mixing, but less well suited for areas or years of high current velocity.

Characterization and evolution of spearfishing in Madeira archipelago, Eastern Atlantic

2020 ◽  
Vol 33 ◽  
pp. 15
Author(s):  
Roi Martínez-Escauriaza ◽  
Claudio Vieira ◽  
Lídia Gouveia ◽  
Nuno Gouveia ◽  
Margarida Hermida
Keyword(s):  
Fish Species ◽  
Young Men ◽  
Coastal Areas ◽  
Teleost Fishes ◽  
The North ◽  
Southeast Coast ◽  
Madeira Archipelago ◽  
First Time

Data obtained from licenses of spearfishers and surveys conducted in 2004 and 2017 allowed for the analysis, for the first time, of the practice of spearfishing in the Madeira archipelago. Only a small percentage of the population practices spearfishing, mostly local young men. Most of them practice the activity with a partner throughout most of the year and along most of the island's coastal areas, although preferentially along the North and Southeast coast. Results show how, in recent years, despite the population of spearfishers decreasing, the abundance in the annual catch potentially increased, probably due to the higher investment of time in this activity. It has been observed that many fishers complement their catches with manual collecting of invertebrates. Overall, 40 teleost fishes and also 4 crustaceans and 8 molluscs were identified. The most frequently captured fish species were parrotfish and white seabream, while limpets were the most collected invertebrates in both selected periods.

Somatic Embryogenesis and In vitro Plant Regeneration in Vigna trilobata (L.) Verd. - A Potential Pasture Legume

1970 ◽  
Vol 19 (1) ◽  
pp. 89-99
Author(s):  
K. Choudhary ◽  
M. Singh ◽  
M. S. Rathore ◽  
N. S. Shekhawat
Keyword(s):  
Somatic Embryogenesis ◽  
Growth Regulators ◽  
Somatic Embryos ◽  
Basal Medium ◽  
Long Term Study ◽  
Continuous Application ◽  
First Time ◽  
Pasture Legume

This long term study demonstrates for the first time that it is possible to propagate embryogenic Vigna trilobata and to subsequently initiate the differentiation of embryos into complete plantlets. Initiation of callus was possible on 2,4-D. Somatic embryos differentiated on modified MS basal nutrient medium with 1.0 mg/l  of 2,4-D and 0.5 mg/l  of Kn. Sustained cell division resulted in globular and heart shape stages of somatic embryos. Transfer of embryos on to a fresh modified MS basal medium with 0.5 mg/l of Kn and 0.5 mg/l of GA3 helped them to attain maturation and germination. However, the propagation of cells, as well as the differentiation of embryos, were inhibited by a continuous application of these growth regulators. For this reason, a long period on medium lacking these growth regulators was necessary before the differentiation of embryos occurred again. The consequences for improving the propagation of embryogenic cultures in Vigna species are discussed. Key words: Pasture  legume, Vigna trilobata, Globular, Heart shape, somatic embryogenesis D.O.I. 10.3329/ptcb.v19i1.4990 Plant Tissue Cult. & Biotech. 19(1): 89-99, 2009 (June)

An Evaluation of Provincial Macroeconomic Performance in Vietnam

2017 ◽  
pp. 34-47
Author(s):  
Hoi Le Quoc ◽  
Nam Pham Xuan ◽  
Tuan Nguyen Anh
Keyword(s):  
Development Strategy ◽  
Institutional Transformation ◽  
Economic Indicators ◽  
Macroeconomic Performance ◽  
Economic Development Strategy ◽  
Socio Economic Development ◽  
The Cost ◽  
Development Objectives ◽  
First Time

The study was targeted at developing a methodology for constructing a macroeconomic performance index at a provincial level for the first time in Vietnam based on 4 groups of measurements: (i) Economic indicators; (ii) oriented economic indicators; (iii) socio-economic indicators; and (iv) economic - social – institutional indicators. Applying the methodology to the 2011 - 2015 empirical data of all provinces in Vietnam, the research shows that the socio-economic development strategy implemented by those provinces did not provide balanced outcomes between growth and social objectives, sustainability and inclusiveness. Many provinces focused on economic growth at the cost of structural change, equality and institutional transformation. In contrast, many provinces were successful in improving equality but not growth. Those facts threaten the long-term development objectives of the provinces.

SEEDING DENSITY OF DIFFERENT FISH SPECIES IN POLYCULTURE

2017 ◽  
pp. 74-79
Author(s):  
Yuriy Borisovich Lvov
Keyword(s):  
Fish Species ◽  
Silver Carp ◽  
Seeding Density ◽  
Habitat Conditions ◽  
Method Of Calculation ◽  
Fish Breeding ◽  
Trophic Preferences ◽  
Breeding Zone ◽  
Practical Progress

The article touches upon the principles, biological basics and practical progress of introduction of specific and age polyculture of fishes. Using the results of the analysis of literary and long-term native data, there has been offered the gradation of 12 fish species from different families by resistance to habitat conditions. Crucian ( Carassius gibelio ) has been chosen as the most sustainable object of cultivation. There has been taken an attempt to calculate the number of seeding different fish species in polyculture taking into account their physiological features is made. Subject to specific physiological features of the studied species, there was carried out recalculation of their natural reproductive performance in different fish-breeding zones, which is traditionally carried out for a carp ( Cyprinus carpio ). In particular, in the second fish-breeding zone with area of 1 hectare it is possible to breed 120 kg of carp, or 150 kg of crucian, or 75 kg of silver carp ( Hypophthalmichthys ). Overall productivity is made up of a share of fishes in polyculture, but taking into account tolerance of species, it can be lower than productivity calculated for carp. The method of calculation and formulas which give the chance to determine seeding density of fish species for breeding in polyculture have been offered. This technique makes it possible to use trophic preferences and consider tolerance of each species to the conditions of breeding areas.

NEW VARIETIES OF CURRANTS AND GOOSEBERRY BREEDING PLANTS

1970 ◽  
pp. 41-46
Author(s):  
O. D. Golyaeva ◽  
O. V. Kurashev ◽  
S. D. Knyazev ◽  
А. Yu. Bakhotskaya
Keyword(s):  
Powdery Mildew ◽  
Genetic Basis ◽  
Black Currant ◽  
Leaf Spots ◽  
Agricultural Sciences ◽  
Berry Crops ◽  
New Varieties ◽  
First Time ◽  
Red Currant

The main goal of the scientific institution was and remains to improve the assortment of fruit and berry crops for the development of domestic horticulture. Black currant breeding at VNIISPK was started by A.F Tamarova and continued by the doctor of agricultural Sciences T.P.Ogoltsova and doctor of agricultural Sciences S.D. Knyazev. A long-term breeding program has been developed. The main goals of the program are to create black currant cultivars with continuous resistance to diseases, first of all powdery mildew, as wells resistance to pests, i.e. bud mite. As a result of the long-term work, over 40 black currant cultivars have been developed, 14 of them are zoned. Red currant breeding was led by the candidate of agricultural Sciences L.V. Bayanova; since 2001 the work has been continued by the candidate of agricultural Sciences O.D. Golyaeva. ‘Heinemanns Rote Spӓtlese’, the descendant of R. multiflorum Kit., was involved in the red currant breeding for the first time in Russia. On its genetic basis, a series of late maturing cultivars with long and dense racemes was created. At the Institute, in total 21cultivars of red currants have been developed, 13 of them are zoned. At present, red currant cultivars make up 25.5% of the zoned assortment in Russia. The first research on gooseberries was stated by V.P. Semakin and A.F Tamarova; since 1992 the systematic gooseberry breeding has been carried out by the candidate of agricultural Sciences O.V. Kurashev. On the basis of Grossularia robusta, we have created gooseberry forms that are resistant to powdery mildew and leaf spots. These forms are highly productive, weakly thorned, having bush habit suitable for mechanized harvest. The result of breeding activities was the transfer of 6 gooseberry cultivars to State agricultural testing: ‘Solnechny Zaychik’, ‘Nekrasovsky’, ‘Yupiter’, ‘Zemlianichny’, ‘Moryachok’ and ‘Discovery’.

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