Search results for "benthic"
showing 10 items of 350 documents
Sources and transfer of organic matter in food webs of a Mediterranean coastal environment: Evidence for spatial variability
2006
Abstract The spatial variability in the food web structure of a Mediterranean semi-enclosed coastal environment (Stagnone di Marsala, Italy) was investigated using stable carbon and nitrogen isotopes. Organic matter sources and consumers were sampled in two locations with different environmental features (e.g. hydrodynamic regime, open-sea influence, vegetal coverage). Overall more 13 C-enriched and 15 N-depleted values were found in the central location than in the southern for organic matter sources and consumers. Pelagic consumers (zooplankton and juveniles of transient fish) showed slight spatial differences and in both locations seemed to depend on phytoplankton as the ultimate energy …
Relationship among anthropogenic pollution, benthic foraminifera assemblages and their morphological deformations from marine sediments of the Sicili…
2009
Benthic hydroids from the south of Livingston Island (South Shetland Islands, Antarctica) collected by the Spanish Antarctic expedition Bentart 94
2006
Twenty-five species of benthic hydroids were collected during the Spanish Antarctic expedition Bentart 94 from the south of Livingston Island (Antarctica). All species are considered regarding autecology and geographical distribution. The systematic position amongst allied species is discussed when considered necessary. Antarctoscyphus asymmetricus and Symplectoscyphus nesioticus are reported for the second and the third time, respectively.
Heterogeneous vertical structure of the bacterioplankton community in a non-stratified Antarctic lake
2013
10 páginas, 4 figuras, 2 tablas.
Recent benthic foraminiferal assemblages and their relationship to environmental variables on the shoreface and inner shelf off Valencia (Western Med…
2014
The environmental variables that determine the distributions of benthic foraminiferal assemblages on the shoreface and inner shelf of the north of Valencia province (Western Mediterranean) are identified. The possible influence of variables such as water depth, distance from shore, hydrodynamics, substrate type, carbonate content, organic matter content and human activity is evaluated. Multivariate cluster-Q-type analysis and redundancy analysis (RDA) are used to identify the environmental variables that have the greatest influence on the assemblage distribution. The spatial distribution of the assemblages is closely associated with water depth and substrate. The diversity and abundance of …
Environmental reconstruction of Trapani saltmarsh (southwestern Sicily) during the last 80 years. An integrated approach by using benthic foraminifer…
2013
Forest drainage: a threat to benthic biodiversity of boreal headwater streams?
1998
1. Forest drainage, including mainly ditching of waterlogged peatlands in order to increase wood growth, has caused substantial changes in the hydrology and water quality of Finnish streams. However, knowledge on the ecological impact of these changes is poor. This paper studies the potential impact of forest drainage, catchment characteristics and habitat factors on the water quality and benthic macroinvertebrates in headwater streams of the River Isojoki, western Finland. An intensive programme of water sampling was carried out at nine study sites, while zoobenthic samples covered a total of 18 streams. 2. According to multivariate regression models concentrations of aluminium and suspend…
Changes in habitat structure, benthic invertebrate diversity, trout populations and ecosystem processes in restored forest streams: a boreal perspect…
2007
SUMMARY 1. Most Finnish streams were channelised during the 19th and 20th century to facilitate timber floating. By the late 1970s, extensive programmes were initiated to restore these degraded streams. The responses of fish populations to restoration have been little studied, however, and monitoring of other stream biota has been negligible. In this paper, we review results from a set of studies on the effects of stream restoration on habitat structure, brown trout populations, benthic macroinvertebrates and leaf retention. 2. In general, restoration greatly increased stream bed heterogeneity. The cover of mosses in channelised streams was close to that of unmodified reference sites, but a…
Amusium cristatum shell beds in the lower Pliocene deposits of Almería-Níjar Basin (SE Spain)
2020
Densely packed monospecific-paucispecific Amusium cristatum-dominated shell beds are signifi cant features in the lower Pliocene deposits of the Almeria-Nijar Basin (SE Spain), embedded in distal prodelta fi ne-grained sand and silt. The shells in these concentrations are exceptionally well preserved: articulation is relatively high, fragmentation is low, abrasion is almost lacking, and many shells preserve the original colour pattern. These taphonomic signatures suggest in situ deposition forming autochthonous fossil assemblages, i.e. biological concentrations. Benthic foraminiferal assemblages found in the prodelta deposits indicate that they formed in mesotrophic mid-shelf settings.The A…