scholarly journals A review of reproduction biology and spawning/ nursery grounds of the most important Adriatic commercial fish species in the last two decades

2020 ◽  
Vol 61 (1) ◽  
pp. 89-100 ◽  
Author(s):  
Barbara Zorica ◽  
Ana Pešić ◽  
Bojan Marčeta ◽  
Milica Mandić ◽  
Corrado Piccinetti ◽  
...  

Recently, despite long-term systematic research of the Adriatic Sea ecosystem, the necessity to improve the existing protection of commercially exploited species occurred since the status of many renewable marine stocks were not in good state. In order to realize that review of scientific knowledge gather within the last two decades was required. In this paper emphasis has been placed on all the scientific knowledge concerning the reproductive biology, spawning and nursery grounds of four ecologically and economically important Adriatic fish species – sardine Sardina pilchardus, anchovy Engraulis encrasicolus, European hake Merluccius merluccius, Common pandora, Pagellus erythrinus. Main aim of this review was to establish new scientific platform that in near future should result with better conservation measures that will insure long-term sustainability of exploited marine living resources.

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.


2013 ◽  
Vol 70 (3) ◽  
pp. 694-706 ◽  
Author(s):  
Wolfgang Nikolaus Probst ◽  
Matthias Kloppmann ◽  
Gerd Kraus

Abstract Probst, W. N., Kloppmann, M., and Kraus, G. Indicator-based status assessment of commercial fish species in the North Sea according to the EU Marine Strategy Framework Directive (MSFD). – ICES Journal of Marine Science, 70: 694–706. The EU Marine Strategy Framework Directive (MSFD) is structured into eleven descriptors of good environmental status (GES). For each descriptor the current status of the marine environment should be assessed against its GES using ecosystem criteria and indicators. Within Descriptor 3 (D3) the MSFD addresses the status of exploited fish stocks according to three criteria (exploitation rate, stock size and size structure). This study performed an MSFD-compliant assessment of exploited fish stocks in the North Sea by aggregating data from analytical stock assessments and scientific research surveys to calculate indicator metrics for each criterion within each stock time-series. A stock achieved GES, when each indicator for each criterion had a good status. Of 43 assessed fish stock suggested by the EU Data Collection Framework, 63% (27) achieved GES. Though the MSFD explicitly demands that all exploited fish stocks achieve GES, this demand may be challenged by reality, because the status of exploited stocks depends not only on fishing impacts, but also on environmental conditions and ecological interactions. Therefore an alternative approach based on binomial distributions is presented to define limits for GES at the descriptor level. The implications and pitfalls of the applied assessment methods are discussed.


2021 ◽  
Vol 22 (Special Issue) ◽  
Author(s):  
Ulgen Aytan ◽  
Fatma Basak Esensoy ◽  
Yasemen Senturk ◽  
Esra Arifoglu ◽  
Kaan Karaoglu ◽  
...  

The occurrence of micro- (<5 mm), meso- (5–25 mm) and macroplastics (>25mm) was investigated in seven commercial fish species of the Black Sea. Plastics were found in gastrointestinal track of all species analysed: Engraulis encrasicolus, Trachurus mediterraneus, Sarda sarda, Belone belone, Pomatus saltatrix, Merlangius merlangus and Mullus barbatus. A total of 352 plastic particles were removed from 190 individuals (29% of all individuals examined). The mean number of plastic particles per fish was 0.81±1.42 par.ind-1 (considering all fish analysed, n=650) and 2.06±1.09 par.ind-1 (considering only the fish that ingested plastic, n=190). The most common types of plastics were fibres (68.5%), followed by films (19%), fragments (11.9%), foams (0.3 %) and microbeads (0.3%). The most common plastic colour was black (39.3%) followed by blue (19.5%) and transparent (18.1%). The length of plastics ranged from 0.05 to 26.5 mm with an average of 1.84±2.80 mm. 93.2% of plastics were microplastics, 6.5 % as mesoplastics and 0.3% macroplastics. Plastic occurrence was higher in S. sarda (plastic in 70% of the analysed individuals) and lower in M. merlangus (plastic in 9% of the analysed individuals). The main synthetic polymers identified by Fourier-transform infrared (FTIR) spectroscopy were polypropylene (29.8%), polyester (17.5%), acrylic (15.8%), polyethylene (14%) and polystyrene (1.8%) and 21.1% of polymers were cellulosic. Results show that commercial fish of the Black Sea is contaminated by plastics. This might affect vital functions of fish and pose a risk to ecosystem and human health. The study contributes to a better understanding of the status of plastic pollution in the fish from different habitats of the Black Sea and provides baseline data to implement the Marine Strategy Framework Directive in the basin.


Author(s):  
Maral Aydynkyzy Zhaparova ◽  
Saule Zhangirovna Asylbekova ◽  
Damir Kayirkeldyevich Zharkenov ◽  
Kuanysh Baibulatovich Isbekov ◽  
Vyacheslav Nickolaevich Tsoy

This article presents materials on the current state of the native ichthyofauna of the Ile-Balkhash basin, affected by large-scale acclimatization works. Four species of the ichthyofauna composition are listed in the Red Book of Kazakhstan: spike ( Acipenser nudiventris Lovetsky, 1828), Aral barbel ( Barbus brachycephalus brachycephalus Kessler, 1872), Balkhash marinka ( Schizothorax argentatus argentatus Kessler, 1874), Balkhash perch ( Perca schrenkii Kessler, 1874). Due to the ineffectiveness of fish conservation measures, including the prohibition for catching of these fish species, which are not found anywhere except in the Ile-Balkhash basin, it is necessary to impose artificial reproduction, changes in the Fishery Rules and organization of commercial rearing. The work is based on research materials of 2001-2018 conducted in Lake Balkhash, the delta and the lower reaches of the Ile and the Tokraun. The status of spike populations ( Acipenser nudiventris Lovetsky, 1828), Aral barbel ( Barbus brachycephalus brachycephalus Kessler, 1872), Balkhash marinka ( Schizothorax argentatus argentatus Kessler, 1874) and Balkhash perch ( Perca schrenkii Kessler, 1874). The main reasons preventing the maintenance of a high number of endangered species have been established: small area of natural spawning grounds, death of fry in linmeshing fishing gear, large-scale poaching (spike); deterioration of conditions for the natural reproduction, mass mortality of young fishes in the irrigation system (Aral barbel); total elimination and food competition with pike perch (Balkhash marinka, Balkhash perch). The prospects for preservation of rare and endangered fish species have been considered, recommendations for breeding and replenishing populations of species listed in the Red Book have been given: measures for artificial reproduction and prevention of juvenile death, creating favorable conditions for fattening and reducing the pressure of trophic competition. Without taking adequate measures for reducing the anthropogenic impact on natural resources, including ichthyofauna, the number of main commercial fish species will decrease, rare species of fish will die out.


2017 ◽  
Vol 41 (3) ◽  
pp. 447-458
Author(s):  
Alfredo Pérez-Lozano ◽  
Barbarino Aniello

Population parameters, performance index (∅) and exploitation rates (E = F/Z), of the 14 most important commercial fish species, in the Apure River, were estimated from length frequency distributions of commercial catches in the period 2000-2003. Growth parameters were used to determine the status of the principal fisheries resources of the Apure River. The analyzed species represented 83% of the total commercial species. The results showed a predominance of values relativity low of K and high L∞, common in longevity species. This data combined with the high values from estimations of Z and F showed a survival annual high rate and low stock tuner-over rate. The E estimations for the 14 fish species were high. E0,1 (0.50- 0.94). The overfishing indicators to four most fish species abundant (P. mariae, P. tigrinum, M. duriventre y H. littorale), showed that at least three species were heavy exploited. In general the analysis indicate that these 14 fish species have been strongly fished, and the data obtained is a starting point (as biological reference point) to be used for the assessment and management of fisheries resources in the Apure River.


1997 ◽  
Vol 2 (4) ◽  
pp. 293-300 ◽  
Author(s):  
Ype H. Poortinga ◽  
Ingrid Lunt

In national codes of ethics the practice of psychology is presented as rooted in scientific knowledge, professional skills, and experience. However, it is not self-evident that the body of scientific knowledge in psychology provides an adequate basis for current professional practice. Professional training and experience are seen as necessary for the application of psychological knowledge, but they appear insufficient to defend the soundness of one's practices when challenged in judicial proceedings of a kind that may be faced by psychologists in the European Union in the not too distant future. In seeking to define the basis for the professional competence of psychologists, this article recommends taking a position of modesty concerning the scope and effectiveness of psychological interventions. In many circumstances, psychologists can only provide partial advice, narrowing down the range of possible courses of action more by eliminating unpromising ones than by pointing out the most correct or most favorable one. By emphasizing rigorous evaluation, the profession should gain in accountability and, in the long term, in respectability.


Author(s):  
Yuriy Borisovich Lvov

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.


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.


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