Fishing Vessel Navigation

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.

2015 ◽  
Vol 21 (1) ◽  
pp. 39
Author(s):  
Andria Ansri Utama ◽  
Setiya Triharyuni

The Jakarta Bay is known as a fishing ground area for several traditional types of fishing gears. The fishery has important role to provide nutrition, sustainable livelihoods, and poverty alleviation around the area. Abundance estimation of commercial fish species in the Jakarta Bay is essential particularly comparable of series data in order to evaluate the potential changes in distribution and abundance. The purpose of this study is analyzing the distribution of commercial fish species in the Jakarta Bay and estimate their abundance and biomass. Fish assemblages were concentrated in the eastern and central part of bay. Apparently salinity and DO associated with rich density of phytoplankton and zooplankton may explain the spatial variability of short-bodied mackerel and pony fish, while assemblages pattern of spiny hairtail and croaker might be driven by the availability of small planktivorous fish as their diet. The most abundant commercial fish in the Jakarta Bay are Short-bodied mackerel (<em>Rastrelliger brachysoma</em>), Ponyfish (<em>Leiognathus</em> sp.), Croaker (<em>Johnius</em> sp.) dan Spiny hairtail (<em>Lepturacanthus savala</em>) respectively. Furthermore, biomass estimates for those species showed short-bodied mackerel has the highest biomass followed by spiny hairtail, croaker, and ponyfish.


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.


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.


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.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Fathi Alhashmi Bashir ◽  
Mohammad Shuhaimi-Othman ◽  
A. G. Mazlan

This study is focused on evaluating the trace metal levels in water and tissues of two commercial fish species Arius thalassinus and Pennahia anea that were collected from Kapar and Mersing coastal waters. The concentrations of Fe, Zn, Al, As, Cd and Pb in these coastal waters and muscle, liver and gills tissues of the fishes were quantified. The relationship among the metal concentrations and the height and weight of the two species were also examined. Generally, the iron has the highest concentrations in both water and the fish species. However, Cd in both coastal waters showed high levels exceeding the international standards. The metal level concentration in the sample fishes are in the descending order livers > gills > muscles. A positive association between the trace metal concentrations and weight and length of the sample fishes was investigated. Fortunately the level of these metal concentrations in fish has not exceeded the permitted level of Malaysian and international standards.


2008 ◽  
Vol 391 (1) ◽  
pp. 159-167 ◽  
Author(s):  
Denise Fernandes ◽  
Maria João Bebianno ◽  
Cinta Porte
Keyword(s):  

Author(s):  
N. Ozerova

Based on the data from economic notes to the General Land Survey, the ranges of commercial fish and crayfish species that inhabited waterbodies of the Moscow River basin in the second half of the 18th century are reconstructed. Eighteen maps showing the distribution of 22 fish species, including Acipenser ruthenus L., Abramis brama L., Barbatula barbatula L., Lota lota L., Sander lucioperca L. and others are compiled. Comparison of commercial fish species that lived in the Moscow River basin in the second half of the 18th century with data from ichthyological studies in the beginning of the XXI century and materials of archaeological surveys shows that almost all of these species have lived in the Moscow River basin since ancient times and have survived to the present day.


2022 ◽  
Vol 301 ◽  
pp. 113918
Author(s):  
Brian Pentz ◽  
Nicole Klenk
Keyword(s):  

Author(s):  
Andrey Dmitrievich Bykov ◽  
Svetlana Yuryevna Brazhnik

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.


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