Search results for " dredging."
showing 4 items of 4 documents
Catastrophic effects of sand mining on macroinvertebrates in a large shallow lake with implications for management
2019
Sand mining is a human activity that is increasing in inland waters and has profound effects on entire aquatic ecosystems. However, current knowledge of the effects of sand mining on freshwater lake ecosystems remains limited, especially for biotic communities. Here, we investigated the responses of macroinvertebrates to indiscriminate sand mining in a large shallow lake of China. Our results indicated that sand mining significantly increased the content of suspended particulate matter, total nitrogen, total phosphorus and chlorophyll a in the water column both in the sand mining area and the area adjacent to the dredging activities. While there was significantly lower total nitrogen and th…
COMPOSITION AND QUALITY OF FRESHWATER LAKE SEDIMENTS (BALVU AND PĒRKONU LAKES)
2019
Water quality, watershed basin and urbanization are key factors from the perspective of freshwater management; however, actual depth of waterbodies is often an overlooked element. Actual depth represents the overall depth of lake bed and depth of sediments. Some cases have been reported, where with increase of average depth of lake , it is possible to expect improvements of water quality when sediments are removed. If lakes are eutrophic, shallow, overgrown with macrophytes and contain high concentrations of biogenic elements water and lake ecosystem quality can be endangered. Removal of sediments can be an expensive procedure and also depends on the composition, structure, local conditions…
Contaminated sediments from dredging activities as modern turbidites: geochemical signatures in box-core sediments from the Augusta area, Ionian Sea,…
2009
The Augusta area (SE Sicily) is one of the most industrialized and contaminated coastal environments in the Mediterranean region, having a relatively high influx of unregulated industrial effluents. Valuable sets of geochemical data (major elements and trace metals), obtained from box-core sediments collected along a transect from the Sicilian coastal zone seawards of Augusta and dated via 210Pb and 137Cs, indicated increased metal contamination (notably Hg) since ca 1940-1950, related to the industrial development of the area. Metal enrichment is considerable in the coastal sediments, being significantly in excess (for Hg and Pb) of background values estimated for the Strait of Sicily. Mor…
EVOLUZIONE DELLA LAGUNA DI TONNARELLA (MAZARA DEL VALLO, TRAPANI) E SUO ATTUALE VALORE ORNITOLOGICO
2016
Temporal changing of Tonnarella lagoon (Mazara del Vallo, Trapani) and its current ornithological value. Aims of this work were to highlight the importance of a small and artificial recently formed wetland area, that presents different interesting ornithological peculiarities. The Tonnarella lagoon is a breeding site of Little Tern Sternula albifrons and Kentish Plover Charadrius alexandrinus, both classified as “endangered” species in 2011 by the Red List of breeding birds in Italy; the site is considered of “national importance“ for Kentish Plover and “recorded site“ for the Sandwich Tern Sterna sandvicensis, due to the consistency of its wintering populations. Besides, the ornithological…