Papers by Jacek Szlakowski
Nature Communications
European rivers are disconnected by more than one million man-made barriers that physically limit... more European rivers are disconnected by more than one million man-made barriers that physically limit aquatic species migration and contribute to modification of freshwater habitats. Here, a Conceptual Habitat Alteration Model for Ponding is developed to aid in evaluating the effects of impoundments on fish habitats. Fish communities present in rivers with low human impact and their broad environmental settings enable classification of European rivers into 15 macrohabitat types. These classifications, together with the estimated fish sensitivity to alteration of their habitat are used for assessing the impacts of six main barrier types (dams, weirs, sluices, culverts, fords, and ramps). Our results indicate that over 200,000 km or 10% of previously free-flowing river habitat has been altered due to impoundments. Although they appear less frequently, dams, weirs and sluices cause much more habitat alteration than the other types. Their impact is regionally diverse, which is a function of...
This publication is a Technical report by the Joint Research Centre (JRC), the European Commissio... more This publication is a Technical report by the Joint Research Centre (JRC), the European Commission's science and knowledge service. It aims to provide evidence-based scientific support to the European policymaking process. The scientific output expressed does not imply a policy position of the European Commission. Neither the European Commission nor any person acting on behalf of the Commission is responsible for the use that might be made of this publication.
HAL (Le Centre pour la Communication Scientifique Directe), 2017
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
La composition du regime alimentaire et l'intensite de l'alimentation du poisson des glac... more La composition du regime alimentaire et l'intensite de l'alimentation du poisson des glaces (Champsocephalus gunnari) autour de la Georgie du Sud en janvier/fevrier 1991 ont ete analysees pour 3 877 estomacs recueillis a 44 stations. La proportion du krill (Euphausia superba) dans les estomacs et l'intensite alimentaire relevees etaient particulierement faibles en une periode ou des aliments de haute valeur energetique sont necessaires pour la maturation finale des gonades.
Acta Ichthyologica et Piscatoria, 1992
The fish species on the South Georga shelf were sampled in the 1986/87-1988/89 fishing seasons, ... more The fish species on the South Georga shelf were sampled in the 1986/87-1988/89 fishing seasons, during three RV "Profesor Siedlecki '" cruises. The biological structure of fish stocks, the length-frequency and aqe distributions during the period of study are described. The biomass of fish stocks was estimated by the "Swept Area Method "' .
Acta Ichthyologica et Piscatoria, 1990
Growth in length and weight of Psetta maxima in consecutive years of life was determined basing o... more Growth in length and weight of Psetta maxima in consecutive years of life was determined basing on back calculation of age from the otoliths. Von Bertalanffy's equation and Szypul'a!s polynomials were also used.
We estimate over 200,000 km or 10% of previously free-flowing river habitat length has been lost ... more We estimate over 200,000 km or 10% of previously free-flowing river habitat length has been lost due to impoundments, an amount equivalent to the entire length of rivers in Italy. This loss strongly depends on the biogeographical location and a type of impounding barrier. European rivers are disconnected by more than one million man-made barriers that physically limit or completely block aquatic species migration and contribute to the loss of freshwater habitats8. One of the pervasive effects of barriers is the one caused by impoundment, which directly modifies lotic (flowing) stretches of river into lentic (lake-like) habitats5. Depending on structure and composition of fish communities expected at the barrier location the biological consequences may vary. EU-wide analysis of fish communities observed at river sections with low human induced alteration resulted in a macrohabitat classification of European rivers into 15 river types with expected fish community structure. This set a...
Recenzja naukowa: prof. dr hab. inż. Tomasz Heese Politechnika Koszalińska, Katedra Biologii Środ... more Recenzja naukowa: prof. dr hab. inż. Tomasz Heese Politechnika Koszalińska, Katedra Biologii Środowiskowej dr hab. inż. Jacek Kozłowski, prof. UWM
Fisheries Research, 2012
In shallow waters horizontally aimed transducers are used to maximize usable survey volume due to... more In shallow waters horizontally aimed transducers are used to maximize usable survey volume due to the physical limitations of the environment. However, horizontal acoustic measurements of fish lengths are problematic because in mobile applications there is no way to determine the orientation of the fish relative to the axis of the acoustic beam. The draining of Malta Reservoir in Poland (average depth 3 m) provided an unique opportunity to check the accuracy of acoustic estimates of fish biomass. Before draining, detailed investigations of the fish population were performed using standard gillnetting and horizontal echosounding (split beam Simrad EY500, 120 kHz). During the draining of the reservoir fish were collected and weighted. Three different methods were used to convert the horizontal measurements of acoustic energy into fish total length and the biomass estimates were compared with the results of the fish census that was performed during the draining of the reservoir. The best agreement between the acoustic estimates and the fish census of 565 kg ha -1 and 576 kg ha -1 , respectively, was obtained with Method 1, which uses deconvolution to remove the effect of an assumed random distribution of fish aspect angle and a TS-TL relationship derived from a mixed population of European freshwater species . Deconvolution assumes random distribution of fish orientation, which means this assumption is likely to be valid, at least for Malta Reservoir.
Journal of Water and Land Development, 2010
In the Malta Reservoir a total of 16 fish species belonging to six families were recorded in 2008... more In the Malta Reservoir a total of 16 fish species belonging to six families were recorded in 2008. In the Nordic multi-mesh gillnets 4528 fish belonging to 11 species, with the total weight of 149.5 kg, were caught. The total beach seine catch was 34348.9 kg, which in terms of the reservoir area of 64 ha amounted to biomass density 536.7 kg•ha -1 . Of 11 species caught with the beach seine roach (Rutilus rutilus) was the most abundant species (485031 fish, 7578 individuals•ha -1 ) with the highest share in biomass (24283.4 kg, 70.7%). The average electric catch at two sampling sites in the Cybina River running in the reservoir bowl was 105 kg (which gave estimate of 2.6 ton in all), with a marked dominance of the roach, which constituted 65.4% of fish catch in weight and 93% in numbers. Taking under consideration the results of electrofishing the estimated fish density in the Malta Reservoir in 2008 could reach as much as 577.7 kg•ha -1 . The proportion of predatory fish in the fish assemblage biomass was 20.1%.
In the Malta Reservoir a total of 16 fish species belonging to six families were recorded in 2008... more In the Malta Reservoir a total of 16 fish species belonging to six families were recorded in 2008. In the Nordic multi-mesh gillnets 4528 fish belonging to 11 species, with the total weight of 149.5 kg, were caught. The total beach seine catch was 34348.9 kg, which in terms of the reservoir area of 64 ha amounted to biomass density 536.7 kg•ha-1. Of 11 species caught with the beach seine roach (Rutilus rutilus) was the most abundant species (485031 fish, 7578 individuals•ha-1) with the highest share in biomass (24283.4 kg, 70.7%). The average electric catch at two sampling sites in the Cybina River running in the reservoir bowl was 105 kg (which gave estimate of 2.6 ton in all), with a marked dominance of the roach, which constituted 65.4% of fish catch in weight and 93% in numbers. Taking under consideration the results of electrofishing the estimated fish density in the Malta Reservoir in 2008 could reach as much as 577.7 kg•ha-1. The proportion of predatory fish in the fish assemblage biomass was 20.1%.
![Research paper thumbnail of Rozwoj ogolnoeuropejskiej metody oceny stanu ekologicznego rzek na podstawie ichtiofauny - Europejski Wskaznik Ichtiologiczny [EFI plus]](https://attachments.academia-assets.com/76959044/thumbnails/1.jpg)
Streszczenie. Ramowa Dyrektywa Wodna określa ramy działania mające służyć poprawie jakości ekolog... more Streszczenie. Ramowa Dyrektywa Wodna określa ramy działania mające służyć poprawie jakości ekologicznej wód powierzchniowych Wspólnoty. Istotną rolę w ocenie stanu ekologicznego wód odgrywać mają elementy biologiczne, takie jak: fitoplankton, fitobentos, makrofity, bezkręgowce denne i ryby. W 2004 r. opracowano Europejski Wskaźnik Ichtiologiczny (European Fish Index, EFI), który w zamierzeniu miał zapewnić standardowe narzędzie wspomagające realizację Ramowej Dyrektywy Wodnej. Do sporządzenia i testowania wskaźnika EFI wykorzystano archiwalne dane z elektropołowów prowadzonych w rzekach kilkunastu krajów, przeważnie z Europy Zachodniej i Południowej. Możliwość zastosowania tak opracowanego wskaźnika EFI okazała się ograniczona do typów rzek przeważających w bazie danych stanowiących podstawę jego opracowania. Testowanie przydatności wskaźnika do oceny rzek nizinnych, przeważających w północno-wschodnich regionach UE (np. w centralnej i północnej Polsce, północnych Niemczech i Finlan...
Acta Ichthyologica et Piscatoria
Acta Ichthyologica et Piscatoria
Acta Ichthyologica et Piscatoria, 1990
Uploads
Papers by Jacek Szlakowski