Volume 10 (2005)
Articles
BIOLOGICAL RESEARCH ON THE DANUBE WATER QUALITY IN THE BAZIAS - PRISTOL SECTOR
AURA LUNGU, LUMINIŢA GALASIU, VIOLETA ASTRATINEI, FLORENTINA VINTILĂ
The description of surface water quality is a widely used procedure within various environmental protection works and it can be understood on the base of qualitative and quantitative structure of trophic compartments studied in biological analyses. To describe as objectively as possible the ecological state of an aquatic ecosystem it is necessary to know the two main components, the abiotic (biotop) and the biotic (biocenosis) as well as their interrelationships. Biological analysis implies the knowledge of all responses of living beings towards environment; the result is a selection of the best adapted organisms to life conditions. Aquatic flora and fauna can be used to estimate water quality as they respond to the action of different biotic or abiotic, natural or anthropic factors. The bacteriological assessment of freshwater ecosystems such as Danube River is strongly required by the new EU regulations (Water Frame Directive/2000) as a significant parameter, which indicates the ecological changes in the natural state of rivers (JDS, 2002). Inadequately treated wastewater released into aquatic ecosystems can carry bacteria, viruses, protozoa and Helminthes that cause a wide variety of diseases ranging from gastroenteritis and infectious hepatitis to typhoid fever and chronic anemia (Astratinei, 2000). In this study bacterial indicators such as total coliforms, faecal coliforms (thermotolerant coliforms -E. coli) and Faecal streptococci (enterococci) were applied for the assessment of the Danube water quality. According to the EU Framework Directive of Waters 60/2000, the quality of aquatic ecosystems cannot be measured and determined only by physico- chemical indicators; the response of ecosystems should be measured biologically and evaluation methods should take into consideration the factors that determine the structure and functionality of the aquatic ecosystems.
THE RAINFALLS AND FLOODS PRODUCED IN THE HYDROGRAPHIC AREA OF SIRET IN THE YEAR 2005
DAN DĂSCĂLIŢA, PETRU OLARIU, BEATRICE BĂRBIERU
The rainfalls registered in the first decade of the July 2005 in the central and curved area of the Oriental Carpathian Mountains brought to exceeding floods, especially in the hydrographic basins of Bistrita, Trotus, Putna , Rm. Sarat and on the inferior stream of the river Siret. As an effect, these floods generated in the period 11-16.07.2006, calamitous floods, with material damages and human casualties. There were affected the basins and subbasins hydrographic of Bicaz, Tarcau, Trebes, Tazlau, Susita, Putna, Rm. Sarat and on the inferior sector of the river Siret, where the flood was produced by conduction, especially on the river Trotus. The first 6 months of the year 2005 were characterized, in general, by an rainfall excess over the monthly average. Excepting for March, the other months, almost on the entire surface of hydrographic basin of Siret, the rainfall values were over the monthly average. The excess character was obvious in May and in June when the monthly average outdated with over 15% in the most hydrometric stations of monitoring. Important quantities of rainfall were able to re-do the humidity deficit from the ground, registered in the anterior year, and to realize, in the mountain area an excess of humidity.
TERRACE PONDS IN THE CIUC BASIN: A PRELIMINARY CHARACTERIZATION
LÁSZLÓ DEMETER, ZOLTÁN PÁSZTOHY, ANNA-MÁRIA CSERGÕ, IOAN CĂRĂUŞ
Ponds and pools are among the most vulnerable and less studied habitat types worldwide (Williams 1987, King 1998, Wood et al. 2003), but awareness of their biodiversity-conservation, scientific, cultural and educational value increases (Boothby 1999, Nicolet et al. 2004, De Meester et al. 2005 and references within). In Romania there are virtually no studies on their ecology except the papers of Bãnãrescu (1970, 1995) who suggested their protection. Although some ponds, especially alpine ponds are situated on protected areas (Demeter and Mori 2004), there are no areas in Romania protected specifically for ponds. The Ciuc Basin is one of the large tectonic mountain basins of the Eastern Carpathians (60x20 km) (Kristó 1957, 2002) characterized by a cold and humid climate, low amount of precipitation (600 mm yearly average) and low evapotranspiration values. It consists of three sub-units, the Upper, Middle and Lower Ciuc Basin (from North to South). The low altitude areas of basin, with a mean altitude of 650 m, are very rich in wetland habitats. More than 150 small water bodies have been surveyed in a recent study, and the total number may be several times larger (Demeter et al. 2006). Low altitude ponds of natural origin in this area can be divided into floodplain ponds and higher altitude ponds, situated mainly on the second terraces (Demeter 2005) but also on the alluvial fans. For convenience, we name these as “terrace ponds” in the following. Here we (1) present preliminary data on the morphology and distribution of terrace ponds, (2) give a list of some characteristic floral and faunal elements, and (3) put forward hypotheses on the origin of terrace ponds.
ECOLOGICAL STATUS OF THE BERHECI RIVER AND CHINEJA RIVER ACCORDING TO THE REQUESTS OF WATER FRAMEWORK DIRECTIVE
LUIZA FLOREA, ALINA COSTIN
The Water Framework Directive (WFD) expands the scope of water protection to all waters and sets clear objectives that a “good ecological status” must be achieved for all European waters by 2015 and that water use be sustainable throughout Europe. This new overarching system is quite timely as Europe is water resources are facing increasing pressures. There is no time like the present to tackle the challenges and help secure our water resources for today and for future generations. Article 8 of the Directive establishes the requirements for the monitoring of surface water status, groundwater status and protected areas. Monitoring programmes are required to establish a coherent and comprehensive overview of water status within each river basin district. The programmes have to be operational at the latest by 22 December 2006, and must be in accordance with the requirements of Annex V. The objective of surface water bodies monitoring is to establish a classification of all water stations into one of five quality classes or to attribute one of five ecological status (table 1). A water monitoring network shall be designed and operated to provide information on impacts and status of water bodies and assess any change resulting from programmes of measures undertaken in River Basin Plan. The WFD implementation will require comparability of data and information but at present only general criteria on methods and procedures have been defined. One of these methods are presented in this paper.
DATA CONCERNING THE HYDRO BIOLOGICAL CHARACTERISTICS OF DUNÃRENI LAKE (CONSTANÞA COUNTY)
CRISTINA DINU, ADINA RADU, LILIANA TÖRÖK
The Dunãreni (Mârleanu) Lake is situated in the Danube’s holm, the Ostrov-Cernavodã sector, on the territory of the locality Dunãreni (commune Aliman), 35 km from the town Cernavodã (km 319-323 on the Danube). It occupies a surface of 657 ha, from which 450 ha of water lustre. Its hydrographic basin (522 km2) collects the precipitation waters from the Dubromir Valley. The main water supply sources of the lake are: the Danube’s spring high floods which reach 7 hg, the high flood flows formed in the receiving basin in summer time and its owns springs. Regarding the genesis and the evolution, the lake is framed in the category of the fluvial lakes formed on secondary valley which, following the processes of fluvial erosion and accumulation, joined by anastomosis at the confluence with the Danube. The lake has the configuration of a creek-depression with high and abrupt banks and the bottom relatively level on approximately 75% of its surface (GªTESCU, 1971). Following the hydrotechnic arrangements made in 1970, the lake became a fishery. Being an important habitat for the aquatic birds, the lake was declared natural reserve by the Governmental Resolution nr.2151/2004 (the reserve surface of 702,66 ha including also the perimetrical meadows adjacent to the lake).
ECOLOGICAL STUDY ON AQUATIC MACROINVERTEBRATE COMMUNITIES FROM THE SOMEªUL RECE RIVER
ANCA AVRAM, MIRELA CÎMPEAN, CLAUDIA PAVELESCU, CLAUDIA DANĂU
The present paper represents a study concerning the ecology of macroinvertebrate communities from the Someºul Rece river course, with special emphasis on the following groups: oligochaetes, mayflies, stoneflies and water mites. Previous studies concerning the Someºul Rece flora and fauna at two sampling sites located downstream and upstream of Blãjoaia were carried out by a team coordinated by Sarkany-Kiss & Hamar (1999). This study included all the major groups analyzed in the present paper, except for water mites. So far, general studies concerning the groundwater environment in the Someºul Rece catchment area were made by Cîmpean et al., 2003.The list of water mite species from the groundwater habitats was published by Konnarth-Ionescu, 1979, including data from Motaº and Szalay. Mayflies communities from Apuseni Mountains were studied by Gãldean, 1994.
FAUNISTIC, ECOLOGIC AND ZOOGEOGRAPHIC STUDIES ON THE PENTATOMOIDS AND COREOIDS (HETROPTERA, INSECTA) FROM THE NATIONAL PARK MACIN MOUNTAINS (TULCEA COUNTY)
CECILIA (ROMAN) ŞERBAN
Macin Mountains are situated in the SE of Roma nia, Tulcea County, and was build during Hercinic orogenesis. The maximum height of this mountainous massif are somehow over 400 meters and it develops as a parallel peaks, NW-SE oriented, placed where the Danube is turning, in the NW of Tulcea County [Cotul Pisicii (Cat’s turning)]. Macin Mountains are one of that tree subunits of well-defined Dobrogean Horst with distinct tectonic and stratigraphic evolution, the other two being Triassic region of Tulcea and Babadag region, which is newly sedimentary basin, finalized in Cretacic era. The upper and lower relief shapes, defined by the range of tiers, Islander Mountains, valley-lane are, from the genetic and evolutionary view, the result of a long time process of crushing and modeling, started at the end of Paleozoic era. Although they are undersized (sometimes looking like hills), the Macin Mountains individualizes in the north Dobrogean geographic scenery by sharpened and rocky heights, steep slops from where it starts screes to the base. Generally, the climate is a continental excessive one, with warm summers and mild winters. The National Park of Macin Mountains has 11140.2 ha, 99.7% representing forest and 0.3% grassland. The characteristic of this park is represented by the forest ecosystems that ensure ecological stability and most propitious habitat for distinctive herbaceous species. The north-dobrogean forests, complex ecosystems of steppe and forest steppe, are mostly constituted from a deciduous brush mixture, where the basic species are common oak, in the north, and the grey oak and fluffy oak, in the south of the park. The National Park of Macin Mountains own and protect a great diversity of flora and fauna species, most of them being very rare for Romania and the rest of the world and some special habitats of Dobrogea: west-pontic steppes of feather grass, Thymus zigioides, Moesic fluffy oak forest with Paeonia peregrina, grey oak, linden tree and hornbeam. Silene compacta can be found at the northern limit of the worldwide specific spreading and Potentilla bifurca, at the western limit. Some of vulnerable species, included on the Red List, can be founded too: Campanula romanica, Moehringia grisebachi, Galanthus plicatus, and Dianthus nardiformis. Dobrogea’s heteroptera studies are dating from the second half of XX century and was made by Geza Horvath, A. L. Montandon, Maurice Jaquet, O. M. Reuter, Sienkiewicz and Paraschivescu (1963), Negru ªtefan (1967), for the south of Dobrogea. For the north of Dobrogea, precisely for the Macin-Tulcea-Niculitel region, the studies was made by Kiss B., in 1976, the author mentioned 239 species of heteroptera which belongs to 28 families.
CASES TYPES AND BUILDING MATERIALS ON SOME CADDISFLYES SPECIES (TRICHOPTERA, INSECTA) FROM THE SUPERIOR BASIN OF BISTRIÞA RIVER
DIANA GHEŢEU, ANCA NEAGU, VIOREL IONESI, IONEL MIRON
The present work, dealing with benthic fauna of the Bistriþa River, was developed following some observations on trichoptera pupal and larval cases. It is well known the building instinct of these insects’ larvae. L. Botoºãneanu (1963) made a classification of all construction types of aquatic larvae of insects, separated in systematic groups from our country (also mentioning exotic species with special types of buildings). Some criteria of his classification are: the shape, the nature of building materials - organic (silk and other secretions, algae, vegetal detritus, leaves, wood, mollusk shells) or mineral (pebbles, sand), the mobility. The exclusively mineral composition of some trichoptera larvae is already known (most Rhyacophilidae before pupation, Sericostomatidae, Glossossomatidae and other family's larvae), vegetal, or vegetal and mineral construction (most limnephilid larvae). Most of caddisflies larvae keys, scientific articles describe the cases and some of their components in percentage without explanations on the origin or the method of obtaining these percentages. The characteristics of the larval or pupal case are still used to identify the family, genus even species (Tachet et all., 2000). Concerning particularly the species it is not anymore recommended as major criteria because the stressed larva (during the collection for example) which can live the case or, exceptionally, can use another species case after leaving its own (Wallace et all., 2003). The main purpose of this study is to find out if some trichoptera larvae have any preference in choosing a construction material in natural conditions so we took a group of individuals large enough from a microhabitat. The microhabitat is described mainly by the substrate (Angelier, 2000). In our study the substrate was the area of the riverbed under a big rock from which we collected fixed pupa and last instar larval cases) of the species identified as Allogamus auricollis. On the main course of Bistriþa River, in the area of Vatra Dornei, the ground grevel is constituted mainly from cristaline schists present in the riverbed and also eocene calcares - apported by some of the tributaries - but „diluted” in the cristaline in this sector (Donisã & Poghirc, 1968).
DIVERSITY AND THE MAIN ECOLOGICAL REQUIREMENTS OF THE EPIGEIC SPECIES OF CARABIDAE (COLEOPTERA, CARABIDAE) FROM THREE TYPES OF AGRICULTURAL ECOSYSTEMS IN SUCEAVA COUNTY (MOLDAVIA)
MIRCEA VARVARA
Suceava county is located in the northern, north-east extremity of Romania, in the north part of Moldavia, in the upper catchment of the Siret and Bistriþa rivers. The county has an area of 8553 square kilometres, representing 3.6 % of Romania’s area, being the second large county of Romania. The relief is varied: Mountains, plateaus, hills, intramountain and intrahills depressions, valleys etc. The mountain zone covers about two thirds of the county’s area. To the east of mountain zone, there is the Suceava Plateau, which covers about one third of the county’s area. The Suceava Plateau is divided into two plateaus. The Dragomirna Plateau (altitude 300-525 m) and the Fãlticeni Plateau (altitude 400 - 481m). The Climate is temperat – continental with a cooler character because of the northen geographical position of the county and of the predominantly mountain relief. Because of the relief and altitude, the annual average temperature of the air varies between 0º and 8º C. 0º C on the high peaks of the mountains; about 2º C in the middle mountains ;5º C in depressions, and 8º C in the Suceava Plateau. The annual average amount of precipitations varies altitudinally, from 550 mm in the plateau zone to 800 mm in the subcarpatian hills; and from 1200 mm in the regions of the small and middle –seized mountains to 1400mm on the high mountains. Within the ecological conditions of the Suceava county, faunistic research on the curculionids published: (THEODOR and DANILA 1994). Results on the ecological aspects concening the epigeic fauna of carabidae in the potato, maize and clover crops, from Suceava county published: (VARVARA, DONESCU, DASCALU, 1999); VARVARA, BRUDEA, 1999, VARVARA, 1999, 2001). The purpose of this paper is to present a synthesis on the alpha diversity of epigeic ground beetles, the variation of their relative abundance, the Shannon index and evenness, the degree of similitude between sites according to Sörrensen’s coefficient and to have a general view on the main ecological requirements, at the level of individuals and coenoses.
COMMUNITY STRUCTURE OF POLYCHAETES INHABITING SHALLOW-WATERS IN THE CAPE MIDIA – CAPE TUZLA AREA (ROMANIAN COAST, BLACK SEA)
VICTOR SURUGIU
On the Romanian coast of the Black Sea, depths of less than 20-22 m are usually dominated by sandy sediments and cover an area of approximately 700 km2 (Petran, 1997). To the north of Constanþa the sublittoral sands are fine (132-350 μm median grain size), siliceous, of mineral origin, and form a continuous belt of several kilometres breadth from Sulina to Mamaia (Gomoiu, 1969). In the proximity of the mouths of the Danube, the sandy seabed descends only to 10 m depth, due to the intense sedimentation. To the south of Constanþa the sandy seabeds are discontinuous, forming isolated patches among rocky substrata. At depths less than 4 m the sands are medium-grained (203-433 μm median grain-size), organogenous and calcareous (Gomoiu, 1963, 1969). As the depth increases, the medium-grained sands are gradually replaced by fine, mineral, quartz-micacean sands and these, in turn, are replaced by silts (Bãcescu et al., 1971). The biocoenosis of fine sands is of great ecological and economical importance, since it comprises more than 100 benthic taxa and serves as a nursery ground for many fish of commercial importance (Bãcescu et al., 1957, 1965a, 1965b, 1971). Polychaetes inhabiting sandy substrata of the Romanian Black Sea coast have been studied by Bãcescu et al. (1957, 1965a, 1965b, 1967), Dumitrescu (1963), Þigãnuº (1986, 1988, 1990, 1992) and Surugiu (2003). Due to the influence of Danube run-off and to anthropogenic impact, the biocoenosis of fine sands is influenced by large changes in salinity and is subjected to severe eutrophication and pollution. As a result the biodiversity of these fine sands have declined drastically in the last 35 years and the populations of some opportunistic species, particularly within the Polychaeta, have increased significantly (Þigãnuº, 1986, 1997; Petran, 1997). The aim of the present study is to assess the polychaete diversity from the sandy substrata of the Romanian Black Sea coast and to provide information regarding the distribution patterns of the polychaetes in this habitat using quantitative data.
CONTROL EXPERIMENTS OF THE DEFOLIATOR PRISTIPHORA ABIETINA CHRIST. (HYMENOPTERA: TENTHREDINIDAE) FROM SPRUCE STANDS OUTSIDE NATURAL SPREADING AREA IN IAªI
CONSTANTIN CIORNEI, DANIEL OPARIUC
The small spruce fly (Pristiphora abietina Christ.) produced damages in the last few years which covered larger and larger surfaces (more than 5000 hectares), being identified in different region of the country (Olenici, 2005): Sãlaj, Cluj, Mureº, Covasna, Vâlcea, Bacãu, Botoºani, Suceava. In Iaºi County the first damages were identified by silvical staff in the spring of 2004 in the forest district Paºcani (production units II Tãtãruº and IV Sireþel).
WATER QUALITY EVALUATION IN TRANSYLVANIAN RIVERS BASED ON THE DIATOM BIOLOGICAL INDEX (DBI)
NICOLETA VOICINCO, LAURA MOMEU
The diatoms (Bacillariophyta) are well known water quality bioindicators use in the biomonitoring of lothic ecosystems. Diatom Biological Index (DBI) (Prygiel & Coste, 2000) permits to estimate river water quality in monitoring programs. Based on their sensitivity to pollution and computing the DBI makes possible to obtain an evaluation of the degree of both organic pollution and eutrophication, the value of which is relatively independent from the degree of the physical alteration. The system is based on 209 taxa and seven water quality classes (F) defined from fourteen common physical and chemical parameters. River waters may be included in five quality categories: excellent water, good water, mediocre water, acceptable, inferior water respectively. Especially in the European Union, DBI is successfully applied for qualitative assessment of running waters (Gomà et al., 2004; Rollin et al., 2002; Tudesque & Ector, 2002). In Romania it has also been employed for the assessment of water quality in the Someºu Cald and Someºu Mare rivers (Battes et al., 2004; Voicinco et al., 2004). In this paper there are included the DBI values computed for the Arieºu Mare river (2004), Someºu Mare river and his tributaries (Þibleº, Rebra and Meleº) in years 2004-2005.
THE INFLUENCE OF THE SANITARY CONDITION OF THE POST WINTERING CYPRINIDS ON THE FISHING PRODUCTION FROM THE BRATES FARM
AIDA VASILE, GABRIELA MUNTEANU
The development and mass triggering of the ilnesses in fish, which may lead to considerable mortalities may take place mainly during and after the wintering of the fish, being well known the fact that the wintering period is one of the most critical ones in their life. Thus, in conditions consisting of low temperature water, reduction of the intensity of the metabolical processes, secession of feeding and seeing to the energetic needs of the fish based on the acumulated reserves, the setting for wintering under weigth and in unhygenic tanks, unfit for this faze, is vulnerable to attack from pathogenic agents. Due to the fact that lately there have been recorded losses by mortality in fish populations in the period imediately after wintering, the investigation of the health state of the fish right after taking it out of wintering for the purpose of organising measures of preventing and combating of ilnesses. So, during the period of 2003-2004, researches regarding the health conditions after wintering of the main species of cultured fish at the Brates farm have been done. On this farm some losses of the fish material both during wintering and in the next period have been recorded.
THE INFLUENCE OF RAINBOW TROUT (ONCORHYNCHUS MYKISS) AQUACULTURE IN IZVORUL MUNTELUI – BICAZ RESERVOIR ON BENTHIC MACROINVERTEBRATE COMMUNITY STRUCTURE
GABRIEL IONUŢ PLĂVAN, FRANCISC SIMALCSIK, IONEL MIRON
The quantity of organic seston resulted from faeces and unconsumed nutriments from intensive fish farming, can often exceed the capacity of sediment assimilation, determining the intensification of anaerobic processes of bacterial decomposition, guiding to increased H2S and NH4 concentrations with important perturbations in the benthic community structure (Growen et al. 1988); the amplitude of these modifications depends on lake limnological type and size (Koricka & Zdanowski 1981). In Izvorul Muntelui – Bicaz reservoir, the aquaculture of rainbow trout in floating cages experimentally began in 1972, arising nowadays at an industrial production of approximately 70 mt/year. Previous research on the reservoir was not orientated to illuminate the relation between aquaculture and biotic components of the ecosystem (Miron et al., 1983). Our investigation, run in 2004, identified some changes in the structure of benthic macroinvertebrate community, in the aquaculture area, compared to control situations. In this study we present a first synthesis of our observations, to serve like a reference for next research.
STUDY ABOUT THE FISH FAUNA CHANGES IN THE ORGANIC POLLUTED STRETCHES OF CRIªUL REPEDE RIVER (BIHOR COUNTY, WESTERN ROMANIA)
ILIE C. TELCEAN, DIANA CUPŞA, SEVERUS DANIEL COVACIU-MARCOV, ISTVAN SAS
The rivers pollution due by the waste-waters spilling downward from the villages is caused a visible impact on the river’s fish fauna. According to recent studies (Telcean & Károly, 2000; Telcean et all. 2002 a, 2002 b, Telcean et. Bãnãrescu, 2002 c) the organic pollution are affecting an increased number of the Romanian rivers. Criºul Repede River is one of the most important rivers in the north-western Romania. Its course is passing the state border to Hungary there were join the Tisa River. The fish fauna of Criºul Repede River is maintaining less affected comparing to the other Romanian rivers. Although the industrial pollution is missing, the fishes from middle and lower stretches of Criºul Repede River are threatened by a number of human activities. Worst of them are the river damming or levees building along the riverside, also the house-wastes left in the riverbed and the waste-waters spilling. The most harmful is the river damming that is caused the water level fluctuations and the lost of long flowing river sections (Bãnãrescu, 1994). The present paper aims to reveal the local effect of waste-water spilling and the organic accumulation on the riverbed. We need to determine how are these factors to bring the species number decline and the changes of some species occurrence. The diffuse pollution with waste-waters derivate from the villages has a long term influence. The fish populations are not disappearing in these river stretches, but they are registering different changes, more of them being less visible.
PRELIMINARY DATA REGARDING REPRODUCTIVE BEHAVIOUR OF PUMPKINSEED SUNFISH - LEPOMIS GIBBOSUS (LINNAEUS, 1758) (PISCES, CENTRARCHIDAE)
IONEL-CLAUDIU GAVRILOAIE, LOTUS MEŞTER
Parental care may be defined as an association between one or both parents and the young, association increasing the survival chances of the latter (Sargent & Gross, 1986). Among the vertebrates, mammals show a parental care exclusively maternal in 90 % of the families and a biparental care in 10% of the families. There are no mammal species in which only the male takes care of the young. Among the birds, in 90 % of the cases both parents care for the brood and the chicks, in 8% only the female cares for them and in only 2 % the males are taking care alone for the young. Among the fish, the majority of the species show any parental care for the fry, however among the species that do (approximately 20% of the families) the majority present exclusively paternal care (50% of the cases) followed by an exclusively maternal care (30% of the cases) and biparental care (20% of the cases) (Gross, 2005). Unlike other vertebrates, fishes continue to grow in size and, implicitly, in weight after they reach sexual maturity. At fish, both female fecundity and the number of eggs fecundated by the male tend to increase with the body size. The energy spent with the reproduction directly affects the growth; this is why the reproductive future of a fish depends on how much it invests in its growth and how big it gets in body size and weight (Sargent & Gross, op. cit.). At fish species with an exclusive male caring of the brood and fry, it is known the fact that the males loose weight especially during the period they occupy and defend a territory. As a rule, after the breeding period, there is a high mortality as was noticed at the species Lepomis gibbosus (Gross, 1980).
THE OCCURENCE OF ZOOPLANKTONIC MICROCRUSTACEANS IN THE DIET OF NATURAL FISH POPULATIONS FROM LAKE ªTIUCII (NATURAL RESERVE, CLUJ COUNTY)
KARINA BATTES, KLAUS BATTES, IONUŢ STOICA
Lake ªtiucii is a natural waterbody situated at 274.5m a.s.l. in the Transylvanian Plateau (Pop 2001). Lake drainage area, measuring 17.5 km2, is part of the Bonþ Valley, a tributary to the Fizeº River, which connects it to the Someºul Mic River, upstream of Gherla. The lake is surrounded by hills with heights between 470 and 520 m, and unlike most of the lakes from the Plain of Transylvania, it has a natural origin. Lake ªtiucii is the deepest lake in the region (ªerban & Sorocovschi 2003), having a maximum depth of 6.8m, but can still be regarded as a shallow lake. Previous studies concerning Lake ªtiucii biota included mostly algal communities, while ichthyofauna was ignored. This paper represents an attempt to reveal some aspects concerning the structure and characteristics of natural fish populations from Lake ªtiucii, together with their diet with emphasis on zooplanktonic microcrustaceans.
FEEDING HABITS IN RANA ESCULENTA COMPLEX
ANDREEA NICOARĂ, MIRCEA NICOARĂ, MIHAI ERHAN, GABRIEL PLĂVAN
Green frogs food was studied by numerous authors. It is known that food vary according to habitat and season. Ciric river basin is important because of the presence of artificial ponds populated by frogs. These ponds are located in the outskirts of Iaºi town. (North-eastern part). Amphibians, especially green frogs, by their abundance, are an important component of the ecosystem. The aim of the study was to determine the feeding habits in Rana esculenta complex and to complete the research run in the region so far.
DATA REGARDING THE MOVEMENTS OF THE BIG CORMORANT (PHALACROCORAX CARBO SINENSIS) IN THE DANUBE DELTA
VIOREL CUZIC
The birds met on our country’s territory constitute an important component part of Romania’s fauna and, in the case of the migratory species, of Europe’s fauna. At none of a terrestrial or even aquatic group, the phenomenon of seasonal change of place of the populations belonging to different species isn’t so obvious like at birds. The examination of this phenomenon in a place situated at half distance between the equator and pole, that is a middle point like the delta, offered a rich observation material for the elaboration of personal outlooks in this direction (RADU, 1979). The extremely favorable reproduction conditions and the optimal feeding possibilities, especially in the warm period of the year, make the Danube Delta an attractive biocenosis for the big cormorant. Therefore, the difference between the quantity and the quality of the food from a season to another and the variable way of its accessibility, the variation of the yearly and seasonal climatic conditions, have as consequence a special aviphenological dynamics.
SYNANTHROPIC SPECIES IN THE OUTSKIRTS OF BUCHAREST
SANDA LIŢESCU, GABRIELA PASCALE
The study of ruderal and segetal plant associations registered new impulses only during the first half of last century. These associations comprise synanthropic species whose existence and distribution are linked to human activities, as their name indicates (lat. “simul” – together; gr. “anthropos” – man). They may be autochthonous when they are parts of the Romanian flora, or allochthonous if belonging to other floras. Synanthropic associations develop in townships and around them, on barren ground, at the border of roads and park alleys, in agricultural cultures and on their margins, in courtyards of habitations in rural sites, in green spaces between apartment houses in urban conditions, in green spaces of parks and gardens (more or less well managed) of the city, on courtyards of industrial enterprises, on the banks of lakes and rivers where fishing is practiced etc. Everywhere, where human activities are going on weeds are present, as are named popularly segetal and ruderal plants. In current conditions anthropic influence on vegetal diversity is ever stronger, a consequence being the enhancing of adaptation capacity of weeds and the arising of resistant biotypes (Sorghum halepense (L.) Pers., Matricaria perforata Mérat.), so that research on biology, ecology and arealogy of weeds becomes a stringent necessity. Under certain circumstances weeds become significant competitors of agricultural crops and ornamental species. The main method in the struggle against weeds is the use of herbicides, substances which may act by secondary effects upon cultivated plants, sometimes over a long period, and implicitly upon people and animals which eat them. On the other hand utilization of herbicides or other means of control on a large scale could be “over-efficient” leading to the total disappearance of some segetal and ruderal species from the flora of Romania.
ECOTECHNOLOGY, ECOTECHNICS OR ECOLOGICAL BIOTECHNOLOGY
STOICA GODEANU
Since the 1972 UN Conference in Stockholm, as a result of the ever growing demands of human society, ecology has witnessed a rapid development - from a theoretical science to one with profound practical implications which has received the generic name of Applied Ecology. Within it, during the last 2 decades, ecotechnologies have made great progresses, i.e. the activities of managing or restoring the ecosystems affected by various human impacts. These ecotechnologies, incorrectly called ecological biotechnologies, were grouped by the author into ecotechnics, a distinct branch of applied ecology. In the present paper these notions are clearly defined and the domains in which ecotechnologies have been developed so far are specified. During the last century ecology progressed extremely rapidly, from a branch of the biological sciences it became an interdisciplinary science with deep implications not only in the field of biology but also in various branches of the sciences of nature, of the technical sciences or the socio-economic ones (Figure 1) (5, 6, 11).