Nitrogen retention (Nret) and denitrification were studied in the mesotrophic Solina reservoir (south-east Poland) between spring and autumn in 2002 and 2003. Nret was calculated on the basis of the input-output mass balance. The rate of denitrification was measured using the 15N isotope pairing technique in two types of areas; in deep areas, where the bottom sediment makes contacts with the hypolimnion (Dprof), and in the unstratified shallows (Dlitt). The calculated daily load of removed nitrogen (Dtot) varied somewhat from 11.0 to 19.1 mg N m–2 day–1 with a standard deviation of 3.0 mg N m–2 day–1. The limited oscillation noted for Dtot results from the major participation of the deep areas of the reservoir, which are characterised by stable Dprof, as distinct from Dlitt, which varied seasonally from 5.8 mg N m–2 day–1 in November to 109.9 mg N m–2 day–1 in August. The primary factor limiting the denitrification rate was temperature, the other being availability of substrates, mainly organic matter. Nitrogen retention ranged seasonally between –25.0 and 175.9 mg N m–2 day–1. The contribution of denitrification to Nret ranged from 9.0% to 49.8% (mean 16.4%). On average, only 4.9% of the nitrogen external load was denitrified (range 2.6–7.9%, s.d. 1.5%). After comparing obtained data with others available in the literature, we concluded that reservoirs, estuaries and highly-loaded lakes in a river system experience a more limited contribution of Dtot to Nload than is the case in natural lakes.

The significance of denitrification in relation to external loading and nitrogen retention in a mountain reservoir

This investigation reports on weed-bed invertebrate abundance associated with the submersed macrophyte Ceratophyllum demersum L. in Lake Sakadas within Kopacki rit Nature Park (Croatia). Twenty five taxonomic groups, with the dominance of chironomids (79%), were recorded at three stations during the investigation from July 14 to September 8, 2004. Nematodes and large predatory larvae of Zygoptera with 6% were second in dominance, followed by oligochaetes with 5%. Weed-bed invertebrates on C. demersum were more abundant than on Myriophyllum spicatum L. due to different morphology of the host plants. Environmental parameters within C. demersum stands were found in the same range at all stations, but they changed during the season. They indicated eutrophy with the tendency to hypertrophy which is reflected by the composition of the weed-bed invertebrate community.

Interactions of weed-bed invertebrates and Ceratophyllum demersum stands in a floodplain lake.

The invertebrates associated with Myriophyllum spicatum L., were studied during the vegetation period in 2004, at three stations I, II and III, in lake Sakadaš within Kopački rit floodplain, Croatia. A total of twenty one taxa were recorded, with the dominance of the insect larvae representatives. Family Chironomidae had the greatest abundance and represented 67% of all recorded invertebrates, while as nematodes and oligochaetes were especially abundant at the third station. Significant differences in invertebrate abundances were recorded between months of sampling – July and August as well as July and September. Also, stations I and II showed statisticaly important differences in relation to station III, located near lake’s dam. Physicochemical data, including trophic state indices, as well as invertebrate community composition were indicative for eutrophic state of water with a tendency to hypertrophy at all stations in lake Sakadaš.

Invertebrates in Myriophyllum spicatum L. stands in lake Sakadaš, Croatia.

Zmiany stężeń związków azotu i fosforu w wodach zbiorników zaporowych Solina-Myczkowce w latach 1970-2005

Abstract Dams on rivers are known to facilitate the colonisation and spread of aquatic alien and native invasive species, but the actual mechanisms involved are poorly understood. Since the construction of the Solina Dam on the upper San River system in Poland, European perch ( Perca fluviatilis ) have expanded their distribution into the headwaters of this river system, becoming a native invader. In this study, we assessed the spread of perch in detail over time upstream of the Solina Reservoir, and used otolith trace element microchemistry to determine the spawning and larval rearing locations of perch in the catchment upstream of the dam. Extensive sampling over several years across the catchment upstream of the Solina Reservoir confirmed the widespread occurrence of perch into the headwaters of the tributary river systems, with smaller size classes dominating locations closer to the Solina Reservoir. Despite perch being widely distributed upstream of the Solina Reservoir, otolith microchemical analysis indicated the populations from various reservoir tributaries mostly shared the same spawning and larval rearing habitat, most likely the Solina Reservoir. Our results suggest that reservoirs can facilitate the colonisation of river systems by providing a critical habitat element that would be otherwise missing from riverine landscapes, i.e., an extensive and productive pelagic larval rearing environment. This research shows that the impacts of large dams can extend many kilometers upstream from the river reaches directly affected by the resulting impoundment. 

/pdf/reservoirs-facilitate-colonization-of-river-catchments-by-a-3rl5m2pr.pdf

Reservoirs facilitate colonization of river catchments by a native invasive fish through provision of pelagic larval rearing habitat

. The cascade of Solina/Myczkowce dam reservoirs situated in the West Carpathian Mts was investigated. The cascade consists of two reservoirs, the upper one built 35 yr ago on the San and Solinka Rivers of 2100 ha area separated from another one, of 190 ha area, with hypolimnion cold water supplied from the upper one. The offshore zone was investigated monthly (6 sites of upper, 3 sites of lower reservoir) using a tube bottom sampler. Besides numbers, biomass and biodiversity indices, the proportion of predators, plant/detritus-feeders and filter-feeders was assessed. In upper reservoir Solina, with a lack of filter-feeders, a clear preponderance of plant-detritus feeders was observed. Predators, consisting mostly of leeches and hydranchnellids were present. In lower reservoir Myczkowce, all three trophic classes were present in the first year of study in almost equal proportions and in 1998 with slight preponderance of plant/detritus feeders was observed. The Oligochaeta/Chironomidae index in both reservoirs was low, indicating low degree of eutrophication. Only one site in Solina reservoir (near a fish culture) and one in Myczkowce (influenced by tourist activity) showed a high value of this index.

/pdf/trophic-structure-of-the-benthic-invertebrate-community-in-l23b0jvyse.pdf

Trophic structure of the benthic invertebrate community in the littoral zone of a mountain cascade system

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Tadeusz Prus

Author Tools

Chat about Author

Papers

Trophic structure of the benthic invertebrate community in the littoral zone of a mountain cascade system