Search results for "Benthic zone"
showing 10 items of 265 documents
Inter-annual variation in macroinvertebrate communities in a shallow forest lake in eastern Finland during 1990–2001
2003
As a part of the Integrated Monitoring (IM) Programme of Air Pollution Effects on Ecosystems, the macroinvertebrate community of a pristine forest lake was monitored from 1990 up to the present. Lake Iso Hietajarvi is a small and shallow, weakly stratified oligotrophic headwater lake situated in Patvinsuo National Park, eastern Finland. Benthic macroinvertebrates were sampled annually, once in autumn at depths of 3 - 4 m (sublittoral zone) and at 7 m (profundal zone). The water quality of the lake and meteorological characteristics in the area were monitored during the same period. The inter-annual variation in macroinvertebrate abundance and taxonomic composition in the lake unaffected by …
Le diatomee bentoniche del porto di Palermo
1979
Abstract Benthic diatoms in the harbour of Palermo (Sicily).—The first results of a systematic investigation on the benthic diatoms on the fouling settlements, at four selected sites in the harbour of Palermo, are reported. Samples of comparable areas have been examined either on the fouling of vertical walls of the wharfs or on asbestos panels vertically submerged at the same place for at least eighteen months. Seventy-seven species have been found. No marked taxonomic difference is evident between the populations on the stoneworks and those on the panels.
Are biological classifications of headwater streams concordant across multiple taxonomic groups?
2003
Summary 1. Studies assessing human impacts on freshwater ecosystems are typically based on a single taxonomic group, often macroinvertebrates or fish. Unfortunately, the degree to which such macroinvertebrate or fish-based surveys can be generalised across other taxonomic groups remains largely unknown. A prerequisite for useful generalisations is that different taxonomic groups exhibit concordant patterns of community structure across sites. 2. We examined the concordance among fish, benthic macroinvertebrates and bryophytes in 32 streams in a boreal catchment in Finland. Our goal was to test how consistently different taxonomic groups classify stream sites; for example, can site groupings…
Benthic Macroinvertebrate Communities in the Northern Tributaries of the “Iron Gates” Gorge (Danube River)
2014
Abstract The paper presents the structure of the benthonic macro-invertebrates communities in the Berzasca, Sirinia, Liubcova, and Mraconia rivers. The results are based on quantitative benthos samples (95 samples), collected in July 2014 from 19 sampling stations within the study area. In longitudinal profile, the benthonic macro-invertebrate communities of the Sirinia, Liubcova and Berzasca rivers displays relatively large structural variability, while the communities of the Mraconia River displays smaller structural variability. The structure of the benthonic macro-invertebrate communities correlated with the biotope characteristics indicates the good ecological status of the analysed ri…
Ecotoxicity assessment of boreal lake sediments affected by metal mining: Sediment quality triad approach complemented with metal bioavailability and…
2019
Highlights • Ecological risk assessment of metal-contaminated boreal lakes and sediments. • Sediment Quality Triad complemented with bioavailability and body residue studies. • Toxicity studies for natural sediments with several organisms and endpoints • Adverse effects observed. High variation on results between different methods. • Standard toxicity tests not suitable for testing, too low pH hampers the results. There are several methods for studying metal-contaminated freshwater sediments, but more information is needed on which methods to include in ecological risk assessment. In this study, we compliment the traditional Sediment Quality Triad (SQT) approach – including information on c…
Ecotoxicity assessment of natural attenuation effects at a historical dumping site in the western Baltic Sea.
2005
During the late 1950s and early 1960s of the past century, industrial waste material highly enriched in various contaminants (heavy metals, PAHs) was dumped in the inner Mecklenburg Bay, western Baltic Sea. Large-scale shifts in the spatial distribution of heavy metals in surface sediments were mapped by geochemical monitoring in the mid-1980s and 12 years later in 1997. A further study in 2001 was designed to investigate the small-scale spatial distribution of contaminants inside, on top of, and around the historical dumping ground and to examine possible effects to benthic organisms (Arctica islandica, microbiological toxicity tests). The site is located within an area characterized by a …
Sediment characteristics and macrofauna distribution along a human-modified inlet in the Gulf of Oristano (Sardinia, Italy)
2007
We studied the spatial variability and within-year temporal changes in hydrological features, grain size composition and chemical characteristics of sediments, as well as macrofaunal assemblages, along a heavily modified inlet in the Gulf of Oristano (western Sardinia, Italy). The inlet connects the Cabras lagoon to the gulf through a series of convoluted creeks and man-made structures, including a dam and fish barriers built in the last three decades. Sediments were muddy and mainly composed of the "non-sortable" fraction (i.e., < 8 mu m particle size) in all four areas investigated: Lagoon, Creeks, Channel and Seaward. Along the inlet, however, the ratio between the < 8 mu mn and the 8-64…
Effects of aquaculture waste feeds and antibiotics on marine benthic ecosystems in the Mediterranean Sea
2022
Intensive aquaculture is an important source of organic waste and antibiotics into the marine environment. Yet, their impacts on benthic marine ecosystems are poorly understood. Here, we investigated the ecological impacts of fish feed waste alone and in combination with three different antibiotics (i.e., oxytetracycline, florfenicol and flumequine) in benthic ecosystems of the Mediterranean Sea by performing a field experiment. We assessed the fate of the antibiotics in the sediment and their accumulation in wild fauna after two weeks of exposure. Moreover, we investigated the impact of the feed waste alone and in combination with the antibiotics on sediment physico-chemical properties, on…
Ring test for whole-sediment toxicity assay with -a- benthic marine diatom
2009
7 páginas, 3 figuras, 3 tablas.
Reconstruction of the environmental evolution of a Sicilian saltmarsh (Italy)
2013
The present study deals with the reconstruction of the environmental evolution of a Trapani saltmarsh (southwestern Sicily, Italy) by combining different analytical approaches such as metal content evaluation, low-field nuclear magnetic resonance (NMR) relaxometry, and benthic foraminifera identification. A 41 cm core was collected in the sediments of a Trapani saltmarsh (southwestern Sicily, Italy) at a water depth of about 50 cm. Different time intervals were recognized, each characterized by peculiar features that testify different environmental conditions. In particular, the bottom layers of the sediment core (41–28 cm) comprised the lowest amount of mud fraction, only some selected met…