Recovery assessment in Lake Nemi (Italy) after a twenty year period (1981-2001) using plant-associated invertebrates

Lake Nemi was subjected to organic pollution in the 1970s due to domestic wastes, which led to a severe eutrophication process. Local authorities consequently planned a gradual waste diversion programme completed in 1990. Comparison between data on plant-associated invertebrates in the period of maximum eutrophication (1981/82) and twenty years after the total waste diversion (2001/02) was carried out with the aim of demonstrating the performance of this littoral community for the purpose of lake recovery assessment. Following the water clarity improvement characterizing the 2001/02 period, the macrophyte community displayed an amelioration in plant diversification, an enlargement of the colonized area, and an appearance of Charales, important bioindicators of oligotrophic conditions. In complete agreement with this new situation, the invertebrate fauna extended its colonization, and the species composition and quantitative structure changed completely. A considerable increase in species richness and diversity, and significant modifications of percentages and densities of bioindicator taxa (cladocerans, gastropods and acari) showed a very appreciable recovery, which can be defined as a phase of oligotrophication. This trophic state is closely related to nutrient reduction in the water and enhanced by a drift of organic materials from littoral to profundal bottoms. This was due to the remarkable water level reduction of about five meters which occurred in the lake in recent times

Composition and structure of planktonic and benthic communities as a basic information in fishpond culture

Zooplankton and zoobenthos of two fishponds were studied in order to define their seasonal patterns and community structures. The ponds PI and P2, of similar depth and surface, were interconnected, annually fertilized and mostly utilized for grey mullet rearing. P2 was less eutrophic than PI which received further nutrient inputs from the surrounding cultivated area by means of a drainage canal. A total of 25 zooplanktonic species and 14 zoobenthic taxa was recorded, most of which were typical of eutrophic waters. The comparison of the invertebrate fauna between the two ponds showed a strong similarity in the qualitative composition and significant differences in density of some taxa and in the community structure. The results suggest that the analysis of these communities can be a good tool to monitor eutrophication in fishponds in the same way as observed in lakes, and could provide some basic information to improve fishpond management.peer-reviewe

Littoral invertebrates associated with aquatic plants and bioassessment of ecological status in Lake Bracciano (Central Italy)

Lake Bracciano is a large and deep volcanic lake which plays an unquestionable role for drawing water source and for fishing and recreational activities. The existence of a project aimed at increasing the amount of water drawn from the lake suggested the advisability of undertaking an ecological analysis of the invertebrate community associated with aquatic plants in order to obtain a detailed knowledge of its composition, biodiversity and quantitative structure, and to provide a set of basic and essential information for defining the ecological status in the littoral zone and for future bioassessments in the lake ecosystem. A good water quality, approaching oligotrophy, was evidenced both from data on aquatic vegetation, which showed the extensive colonization of Charales (down to a depth of about 20 m), and from faunal parameters such as high species richness and diversity values, presence and abundance of bioindicator taxa (mainly cladocerans and gastropods), abundances of total fauna. Nevertheless, a considerable disappearance of the reed thicket due to the intense shore management for recreational purposes have negatively influenced the colonization of the more shallow and productive waters, so evidencing a negative trend of the littoral quality

short note on an alien planorbella gastropoda pulmonata in volcanic lakes in central italy

This brief note provides further data on the presence, abundance, and shell morphology of a snail species belonging to the genus Planorbella, found in central Italy in the crater lakes Albano and Nemi in 1986 and 2001, respectively. The snail is an alien species in Italy and is very interesting from a taxonomic point of view. A short history of its discovery in the two lakes is also provided

Relative impacts of morphological alteration to shorelines and eutrophication on littoral macroinvertebrates in Mediterranean lakes

Development of effective methods for assessing the ecological status of lakes based on littoral benthic fauna has been hampered by the lack of quantitative data on the relative impacts of key pressures on the benthic community. We used variance partitioning at 126 sites belonging to 14 natural Mediterranean lakes to analyze the pure and shared effects of eutrophication, morphological alterations, microhabitat type, lake morphometry and geographic position on the littoral macroinvertebrate community. The spatial arrangement of the sampling sites was responsible for 9.1% of the total variance in littoral benthic community composition, lake morphometry accounted for 4.3% of variation, and microhabitat type accounted for 3.9%. Communities appeared to be affected primarily by morphological alterations to lake shorelines, and their impact was 2.5 times as important as that of eutrophication. The structure of littoral benthic communities was governed by processes acting at several spatial scales from region to lake scale. Thus, several pressures and the various spatial scales at which these act should be taken into account when implementing methods of assessing lake ecological condition based on littoral benthic invertebrates. Region-specific methods for subalpine and volcanic lakes might enhance the validity of assessment of results of morphological alterations and improve management of those water resources

Protocollo di campionamento e analisi dei macroinvertebrati negli ambienti lacustri

No abstract availableIn questo documento vengono sintetizzate le principali tecniche di campionamento dei macroinvertebrati di ambiente lacustre. Si propongono metodologie standardizzate a livello nazionale utili per il monitoraggio previsto secondo le richieste della Direttiva Quadro sulle Acque (2000/60/CE)

classification of the ecological status of volcanic lakes in central italy

A synthesis is made of biological data collected in the last three decades on five volcanic lakes in Central Italy with the aim of evaluating their environmental status by means of biological parameters related to zooplankton, littoral and profundal zoobenthos frequently used to detect water quality changes in lakes. A number of bioindicators and bioindices were selected for this purpose, as far as possible following an integrated approach using information drawn from physical and chemical variables. Our results allowed the lakes to be classified according to their biological quality level, which proved to be in good agreement with physical and chemical diagnoses. Lake Bracciano exhibited the best environmental quality, due to the presence of a ring waste water collecting system, to its large size and depth, and to its strong hydrodynamism. Lake Martignano followed, with some symptoms of stress in the hypolimnion due to a marked summer deoxygenation. Oxygen depletion in the profundal characterized also Lake Vico, which showed a mesotrophic condition in the sixties, and 20 years later now shows clear signs of increased trophy (meso-eutrophy). Lake Albano seemed meso-eutrophic with total absence of fauna below a depth of 120 m due to a meromictic status. Finally Lake Nemi, exposed to domestic wastes in the 70s, suffered a heavy eutrophication with dramatic algal blooms and fish kills. Following the diversion of discharges that occurred in the early 90s, today this lake is characterized by the partial improvement of many ecological features. The need for integration between physical and chemical analyses and biological data in order to obtain a reliable evaluation of lake environmental quality is stressed, especially as far as routine implementation in managing and recovery procedures is concerned

The invertebrate community of littoral sandy shores in Lake Albano (Italy) : fauna composition and ecological remarks

The zoobenthos associated with littoral sandy substratum in Lake Albano was sampled during one year in order to evaluate its qualitative and quantitative composition. The community was quite diversified (76 identified taxa) and characterized quantitatively by Oligochaeta, Nematoda and Chironomidae and secondarily by Crustacea (Copepoda and Amphipoda). A diagnosis of mesotrophy in the lake littoral was based both on densities of total fauna and bioindicator taxa and values of some bioindices. The possible importance of the N/T ratio (number of species belonging to naidids/number of species belonging to tubificids) is discussed for the first time.La faune macro et méiobentique associée aux sédiments sableux littoraux du Lac d’Albano a été étudiée en vue de déterminer sa composition qualitative et quantitative. Les peuplements d’invertébrés sont diversifiés (76 taxons identifiés) et caractérisés par la prédominance quantitative des oligochètes, des nématodes des chironomides, et, dans une moindre mesure, des crustacés (copépodes et amphipodes). La zone littorale du lac se situerait dans un état mésotrophe et l’utilisation de quelques paramètres de la faune littorale (surtout la densité des taxons indicateurs et les valeurs numériques d’indices biologiques) semblerait pertinente pour apprécier la qualité biologique du plan d’eau.Mastrantuono Luciana. The invertebrate community of littoral sandy shores in Lake Albano (Italy) : fauna composition and ecological remarks. In: Ecologia mediterranea, tome 21 n°3-4, 1995. pp. 101-112

ON ISOCYPRIS-BEAUCHAMPI (PARIS) (OSTRACODA) AND SOME SUGGESTIONS ON THE TAXONOMY OF THE GENUS

Une population d'Isocypris beauchampi a été trouvée dans le Lago Campotosto (Italie). C'est la seconde fois que le genre est signalé en Italie, après que Fox a attribué la population du Lago Maggiore à une nouvelle espèce, Isocypris nocentiniae. L'analyse comparative de ces populations a conduit à la conclusion qu'I. nocentiniae devait être considéré comme un synonyme d'I. beauchampi. A la suite de l'examen d'autres espèces du même genre, on peut également placer I. arnoldi dans la synonymic d'I. beauchampi

The invertebrate community of littoral sandy ahores in Lake Albano (Italy): fauna composition and ecological remarks

The zoobenthos associated with littoral sandy substratum in Lake Albano was sampled during one year in order to evaluate its qualitative and quantitative composition. The community was quite diversified (76 identified taxa) and characterized quantitatively by Oligochaeta, Nematoda and Chironomidae and secondarily by Crustacea (Copepoda and Amphipoda). A diagnosis of mesotrophy in the lake littoral was based both on densities oftotal fauna and bioindicator taxa and values of some bioindices. The possible importance of the NIT ratio (number of species belonging to naididsl number of species belonging to tubificids) is discussed for the first time