Modern characteristics of mass fish species and their parasites in polar reservoirs of the Yenisei basin (on the example of Khantaiskoye)

Author(s):  
Vladimir Ivanovich Romanov ◽  
Vladimir Anatolyevich Zadelenov ◽  
Yulia Konstantinovna Chugunova ◽  
Oksana Gennad’evna Karmanova ◽  
Vladimir Vladimirovich Lukyantsev

Fisheries research was carried out on the Khantayskoye reservoir in 1977–2020. This article presents the results of these works. In the first years after the flooding of the Khantayskoye reservoir, pike and common species of whitefishes (Siberian vendace, peled and whitefishpyzhyan) constituted the basis of the fishery. The share of other fish (carp, burbot, perch) was insignificant. The sharp increase in the food supply for planktophages and benthophages was short-term. Trophic depression began to appear in the early 80s (3–5 years from the moment the reservoir was filled). From this moment to the present time, whitefish species have a slowdown in linear and weight growth, an increase in the timing of puberty, a decrease in fertility. Of the whitefish fish, only Siberian vendace and whitefish are present in the fishery, the numbers of which have significantly decreased. Since the mid-2000s, the number of peled has decreased significantly and this species of fish has become rare in the reservoir. . Currently, there is a relatively high number of pike. Roach, ide, pike and perch actively mastered the channel of Kontiki, where before was practically absent. The increased number of these species affects the number of whitefish in their spawning areas, and their reproduction, including the safety of eggs.The parasite fauna of the main commercial fish species of the Khantayskoye reservoir was investigated. The most pathogenic were myxosporidia Henneguya zschokkei (Gurley, 1894), the causative agent of peptic ulcer disease in whitefishes.

1984 ◽  
Vol 37 (2) ◽  
pp. 279-285 ◽  
Author(s):  
J. H. Witty

The fisherman's task in navigating his craft are threefold:(i) to guide his craft safely and by the most direct route between his terminal ports and the fishing grounds;(ii) to shoot, tow and haul his fishing gear in such a manner as to prevent it being damaged or becoming fast to any obstruction on the seabed;(iii) to search for aggregations of commercial fish species and by lures, snares and the use of towed nets to capture viable quantities of the fish located.The navigation to and from the fishing ground poses the same problems as for other marine craft, but once on the grounds, using towed or encircling nets, the position of the nets, not only horizontally but also in the vertical plane, are as much his concern as is the position of the parent vessel. Most fishing grounds are situated where there are irregularities in the seabed topography or where oceanographical factors provide a rich feeding area for a range of fish species. Alternatively many fish species carry out an annual migratory journey to their spawning areas or towards more favourable environmental conditions, their shoaling behaviour at this time making them particularly susceptible to mass capture.


Author(s):  
Svenja Koepper ◽  
Sri Nuryati ◽  
Harry W. Palm ◽  
Christian Wild ◽  
Irfan Yulianto ◽  
...  

Abstract Despite being an important component of the marine ecosystem and posing health risks to human seafood consumers, fish parasites in Indonesia have yet to be adequately described. Here, we analyzed the diet and metazoan parasite fauna of seven commercial fish species (Alectis indica, Carangoides chrysophrys, Johnius borneensis, Mene maculata, Trichiurus lepturus, Upeneus asymmetricus, U. moluccensis) landed in Java, Indonesia. We isolated 11 endoparasite species, established 22 new host and 14 new locality records, and extended parasitological records of A. indica by 24%, C. chrysophrys by 25%, J. borneensis by 40%, M. maculata by 44%, U. asymmetricus by 100%, and U. moluccensis by 17%. We genetically identified the trematode Stephanostomum cf. uku (of Bray et al. 2005) from Alecta indica for the first time in Indonesia and provided the sequence of its 28S marker. Stomach content analysis revealed seven different prey items, and the examined fish species were grouped into four feeding categories, which differed significantly in their respective endoparasite fauna. All but two examined fish species hosted potentially zoonotic nematodes, which reveal a risk for parasite-borne diseases in Indonesian food fishes and call for more consequent monitoring with regard to seafood safety in this region. With this study, we were able to establish an association between the feeding ecology and the endoparasite fauna of marine fishes which will help to better understand the transmission pathways of (potentially zoonotic) parasites in food fishes in tropical waters.


2009 ◽  
Vol 67 (1) ◽  
pp. 26-40 ◽  
Author(s):  
Janet A. Nye ◽  
Alida Bundy ◽  
Nancy Shackell ◽  
Kevin D. Friedland ◽  
Jason S. Link

AbstractNye, J. A., Bundy, A., Shackell, N., Friedland, K. D., and Link, J. S. 2010. Coherent trends in contiguous survey time-series of major ecological and commercial fish species in the Gulf of Maine ecosystem. – ICES Journal of Marine Science, 67: 26–40. Fish are often delineated into distinct population or stock units that reflect human institutional borders more than ecological factors. In the Northwest Atlantic, there are many species in the broader Gulf of Maine area (GOMA), yet the area is surveyed and managed for the most part in the south by the United States and in the north by Canada. Biomass time-series of 19 representative fish species and total biomass from 7 different surveys conducted by the United States and Canada in the GOMA are compared. All species showed coherent trends in relative biomass across at least two survey time-series, and in many species a single trend could describe all time-series trends accurately. For instance, Canadian and the US time-series of Atlantic cod, Atlantic herring, haddock, thorny skate, and goosefish had comparable trends. Conversely, species such as longhorn sculpin and spiny dogfish showed differing survey time-series trends and asynchronous event timing, suggesting that their population dynamics differ spatially. Collectively, the results demonstrate the value of comparing time-series for common species from contiguous ecosystems and elucidate the relative importance of environmental and fishing factors on each species.


1993 ◽  
Vol 44 (1) ◽  
pp. 193 ◽  
Author(s):  
RG Coles ◽  
WJ Lee Long ◽  
RA Watson ◽  
KJ Derbyshire

From aerial photography (July 1987) and diving surveys (February 1988), 876 ha of seagrasses (eight species) were mapped in Cairns Harbour, tropical north-eastern Queensland. Zostera capricorni was the most common seagrass species and had the greatest biomass at 79 g m-2 dry weight of stems and leaves and 180 g m-2 dry weight of roots and rhizomes. The maximum shoot density found was 4798 shoots m-2 of Halodule pinifolia, the second most common species. Seagrasses were found only between 0.5 and 5.0 m below mean sea level. Zostera capricorni was found at the shallowest depths, Halodule pinifolia at the deepest depths. Twenty species of penaeid prawns, nine of which are marketed commercially, were sampled from the seagrass beds. Abundances of prawns of commercial species were significantly greater on seagrass-covered substrata than on nonvegetated substrata. Overall, 5614 mostly small or juvenile fish, representing 134 taxa, were sampled from seagrasses in Cairns Harbour. The most numerous fish species were a goby, Yongeichthys criniger, and a pony fish, Leiognathus splendens. Only 15 species were highly valued as recreational fish, and only 11 species were highly valued as commercial fish. Of the fish species, five (4%) were highly valued species of both groups. The density of fish on the seagrass beds was estimated to be 8809 fish ha-1.


Author(s):  
P.A. Balykin ◽  
◽  
A.V. Startsev ◽  
G.E. Guskov ◽  
A.S. Grin ◽  
...  

The materials for 2003-2018 on the biological state of sazan of the eastern part of the Taganrog Bay and the Don River delta were summarized. It has been shown that the catches of sazan in the study area consisted of more than half of the fish of younger age groups, the length of which was less than the commercial measure. The ratio of linear and weight growth of sazan is shifting towards a decrease in the mass of one-dimensional specimen, which is indirect evidence of the deterioration of the natural living conditions of semi-migratory fish. In 2019, the carp parasite fauna was represented by 7 species related to monogenes - 2 species, cestodes - 3 species, nematodes - 1 species, crustaceans - 1. The state of the sazan population needs further research.


Author(s):  
Edward Vladimirovich Nikitin

Shallow coastal waters of the Volga river is a flooded feeding area for fish juveniles of nonmigratory fish species. There takes place annual downstream migration of fluvial anadromous fish species from spawning grounds of the Volga river to the Northern Caspian Sea. The most important factors determining the number and qualitative characteristics of fry fishes are the level of the Caspian Sea (currently having a tendency to the lowering), hydrological and thermal regimes of the Volga river. Researches were carried out in definite periods of time. In the summer-autumn period of 2012 fry fishes were presented by 19 species (13 of them were commercial species), which belonged to 9 families. The article gives data on all the commercial fish species. In the first decade of July the maximum number of fry fish was registered in the western part of the Volga outfall offshore - in box 247 (19.86 mln specimens/km2), in the eastern part - in box 142 (20.4 mln specimens/km2). The most populous were roach, red-eye, silver bream and bream; size-weight characteristics were better in the areas remoted from the Volga delta. In the third decade of July the quantitative indicators of fry fish on these areas decreased, size-weight characteristics greatly increased. In the second decade of October in the western part of the seaside there were registered increased pre-wintering concentrations of fish juveniles, their qualitative indicators increased, which is evidence to favorable feeding conditions in 2012.


2017 ◽  
Vol 8 (1) ◽  
pp. 22-28
Author(s):  
Sunardi Sunardi ◽  
Dina Fitria Murad

BINUS Center is the informal educational institution that organizes IT and language training. Inrecent years the revenue BINUS Center continues to decrease, it is evident from the outlet  BINUS Center decreased from year to year. The purpose of making this research is to make strategy planning Business & ICT, create new models of learning supported by ICT strategy,test and measure the results obtained, and then made some strategic ideas at the moment and will come in the form of short-term priorities, medium and long term. The result is a cost that can be in the efficiency, a more flexible, first-class runs with a minimal number of participants, participant satisfaction, and competitive advantage.  Keywords: business strategy, ICT strategy, business process improvement, priority.


Author(s):  
Gonzalo Mucientes ◽  
Katharina Leeb ◽  
Fiona-Elaine Straßer ◽  
David Villegas-Ríos ◽  
Alexandre Alonso-Fernández

1951 ◽  
Vol 5 (4) ◽  
pp. 810-811

A joint meeting of the Research Committee on Agriculture, Fish, Wildlife and Forestry and the Preparatory Fisheries Committee was held in Trinidad on July 9, 1951. The meeting, under the chairmanship of the United Kingdom representative (Frampton), discussed proposals regarding commercial trawl fishing in the Gulf of Paria and the organization of the Fisheries Conference. The committee felt that a survey of commercial trawl fishing should be undertaken at an estimated expense of $2,000. The committee also recommended that the Fisheries Conference, to be held in March 1952 for five days, should meet in Trinidad and have an agenda as follows: occurrence and distribution of commercial fish species in the Caribbean, techniques used in the Caribbean for fish capture, types of fishing craft used, marketing, storing, distribution, conserving methods, and cultivation of fish in ponds.


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