Volume 13 (2007)
Articles
MICROBIOLOGICAL CHARACTERISTICS OF AQUATIC ECOSYSTEMS FROM THE MIDDLE SIRET RIVER DURING 2004-2006
DUMITRA RĂDUCANU, OCTĂVIŢA AILIESEI
Researches on biological productivity of aquatic ecosystems could not be complete if the role of bacterioplankton in the matter and energy flow is ignored. In Siret river, especially at surface of water, existing a specific (autochtonous) microbiota, wich develops function of nutritive supplies, especially organic biodegradable substances. In case of appears a supplementary nutrient sources (caused by pollution) will be changes in the quantitative and qualitative evolution of microbial population. These aspects will be producing negative effects on water utilization in various economical and social interests or on the health of the people who living in riverside area. The aim of this study is the establishing of the microbial pollution (indicated indirectly by total number of germs TNG) and in the same time we follow up certain ecophysiological groups of bacteria involved in substances recycling. Microorganisms play a very important role in the cleaning process of the Siret river and in the wetlands near the main river course. We are monitoring the microbiological indicators in two years, 2004-2006, on seasonal sample. There were collected water sample during the spring (March-April, summer (June July) autumn (October-November) and winter (January-February) The sample station was selected to offer a significant image of development level of bacteria communities. Water sample were analyzed by inoculation on the selective culture media. For interpreting the analyzed data it make the geometrical media for each sampling station, on season and ecophysiological bacteria group. In the same time, it was monitoring several physico– chemical parameters: temperature T, pH of the water, oxygen. Also, we are follow up the influence of the wetlands microbiota to river microbiota.
ORIGIN OF INTRODUCED PSEUDORASBORA PARVA POPULATIONS IN ROMANIA, BASED ON GENETIC MARKERS (16S rRNA)
ISTVÁN FALKA, KATALIN-EMESE MÉRAI, BEATRIX FERENCZ
The place and role of organisms in nature is the result of a long evolutional process, which had as result the integrity of ecosystems. The geographic distribution of species is determined by abiotic (environmental factors, geophysical barriers etc.) and biotic (interspecific relations) factors. In consequence a species will enlarge its area as far as abiotic and biotic factors will allow (Eber&Brandl 1997). One of the side effects of the socio-economic globalization process is the voluntary or involuntary translocation of organisms by humans and the changing of natural barriers. Although introduction of species is not a new phenomenon, the recognition of the impact of these species on native organisms is just started (Lodge 1993).. The initial lack of interest may be explained by the fact, that most of non-native species do not cause spectacular environmental changes or ecological catastrophes (Williamson & Fitter 1996). However, today invasive species and introduction of species are one of the top issues of the scientific world.
SOME ASPECTS OF ALLUVIAL TRANSIT AND CLOGGING OF ACCUMULATION LAKES IN THE TROTUS HYDROGRAPHIC AREA
DELIA GHEORGHE, FLORIN PRISECARU
The problem of alluvial transit across watercourses presents great theoretical and practical importance. The outflow of alluvia represents the effect of the erosive activity exercised by running waters and reflects the erosion potential of the hydrographic network, with direct effect upon the general evolution of the forms of relief and of the geographical morphology, in general. The analysis of the regime of alluvial outflow can offer precious information on the local and regional conditions of denudational processes, determined, in their turn, by environmental conditions (geology, relief, hydro-climatic and bio-geographical factors) and by the dimensions of the anthropic impact. From a practical point of view, the knowledge of solid transit is of vital importance in projecting complex arrangement or flood protection works. There are numerous cases of accumulation lake clogging (respectively, of decrease in their efficiency and effectiveness), of water supply sources for utilities and irrigation or dragging canals, of exacerbation of the riverbed erosion).
THE EFFECTS OF SIRIU DAM ON THE MAYFLY (EPHEMEROPTERA) AND STONEFLY (PLECOPTERA) COMMUNITIES IN BUZÃU RIVER
MAGDALENA - OANA RISTEA
The dam constitutes obstacles for longitudinal exchanges along river systems and as such result in the fragmentation (reduced connectivity) of ecosystems. It not only alters the pattern of downstream flow (intensity, timing and frequency) it also change sediment and nutrient regimes and alter water temperature and chemistry. The dam may be viewed as anthropogenic alterations that disrupt dynamic processes and so impact on the ecological integrity of natural systems. The dam disrupts the river continuum and cause upstream and downstream shifts in abiotic and biotic parameters and processes. They have a significant impact on transport rates and retention within the river system. Dam modifications had significant effects on both abiotic and biotic variables, and macroinvertebrate assemblages exhibited significant longitudinal differences.
ICHTHYOFAUNA STATUS FROM THE SUCEAVA CATCHMENT AREA FROM 2001 TO 2005
KLAUS WERNER BATTES, FERDIN, PRICOPE, DOREL URECHE, IONUT STOICA
The Suceava River, a Siret River right tributary, measures 172.3 km in length, while its catchment area has 2616 km2. The Suceava average discharge measured at the river mouth is 14.1 m3/s and its solid discharge is 5.9 kg deposits/s. The Suceava represents an average-size river (II). 40% from its course flows through mountainous and submountainous areas, while 60% through hilly regions. Due to industrial and domestic wastes coming from the Suceava locality, the river became heavily polluted, but the pollution level decreased after 1990. However, no important river regularization works were made on this particular river course, except for a small dam upstream Suceava.
MONITORING OF THRIPS ATTACK IN THE SEEDLING STAGE OF PLANTS WITH MULTIPLE USES
MARIA CĂLIN, MARCELA FĂLTICEANU, TINA OANA CRISTEA, CAMELIA MIHAELA POPA, MAGDALENA DUMBRAVĂ
Thrips are one of the most difficult pests to control in seedling stage (Maria Calin, 2004, 2005). This pest is very dangerous insects that reproduce rapidly, congregate in tight places that make pesticide coverage difficult. After the insect feed, the results are the deformation of flowers and leaves (Maria Cãlin, 2004, 2005, Dreistadt and all., 2001, 2004, 2007).The tolerance of thrips on plants with multiple uses crops is low. In addition, when Thrips tabaci feed on plants they usually infect the plant with the viruses as: Lycopersicon virus 3, Solanum virus 8, Nicotiana virus 1, Tomato Spotted wilt virus. Once plants are infected, it is too late to do anything except dispose of diseased plants. Thus, the best way to prevent virus infection is to control the thrips (Flint and all., 1998, Maria Cãlin, 2005).A regular monitoring program is the basis of all pest management programs. The best way is to conduct a regular, weekly monitoring program to detect problems in an early stage. This early detection and treatment will result in better pest control since plant canopies are smaller and better spray coverage can be achieved. Plant inspection is needed to assess general plant health and to detect the pests (O´Donnell et all, 2005; Maria Cãlin, 2005).
RESEARCHES REGARDING THE PRODUCTION OF AUTOMATED FISH FEEDING SYSTEMS USED IN SUPER INTENSIVE CULTURE FACILITIES
NICOLAE CRĂCIUN, SORIN PETRESCU, SMARANDA MARIANA POP, LAURENŢIU BURLACU, CĂTĂLINA FLORIANA RADU
During the last few decades several fish feeding methods and techniques have been developed in part as a result of intense aquaculturing and increases in fish demands on the global market and in part for comparative studies to test the influence of certain feeding techniques on fish growth, feed efficiency and feed wastage (Pfeffer 1977, Thorpe et al. 1990, Alanärä 1992a, Kentouri et al. 1993, Paspatis et al. 1999).Generally 3 categories of feeding system or techniques are recognized: hand-feeding, fixed feed ration systems and demand feeding systems. In practice, the choice of feeding system or technique must be made following considerations of type and level of production and the cost of the feeding system. It may be necessary to change different feeding techniques during the production cycle and several techniques may be combined.Hand-feeding is the oldest and most simple feeding technique but it can be very efficient as the farmer has daily contact with the fish and it is possible to make direct observation on the individuals and, thus, a more efficient food distribution can be made. From the point of view of large scale commercial production hand feeding can not be considered a viable option due to high labour costs and as it is a time consuming practice.Electronically operated timer-controlled feeding systems appeared and became popular during the 1970s as a result of intensive fish farming, but were replaced by computer based control units at the end of the 1980s, which offered more options for the regulation and timing of feed delivery. Although the price for purchasing such a device is high, the operational costs are low. When timer or computer-controlled systems are used, the quantities of feed to be supplied are determined on the basis of either feed tables or mathematical models describing daily energy requirements. Demand feeding systems were developed during the 1980s and 1990s for use on commercial farms and are based on the principle that the supply of feed is regulated by the demand of the fish. Demand feeders work in one of the two ways: either by fish requesting feed themselves (self-feeders) or by automatic cessation or reduction of feed delivery when feeding activity declines (interactive feedback systems).
STATISTICAL CONSIDERATIONS ON LETHAL INTOXICATION WITH METHYL ALCOHOL FROM BACÃU DISTRICT DURING THE PERIOD 1994 – 2007
DOINA MOALEŞ, ELENA BUTNARU, MARIA PRISECARU, MARCEL BĂDĂRĂ
Methyl alcohol or methanol is a toxic product, frequently used in the chemical industry, in pharmaceutical, and biochemical laboratories. Its physical-chemical and organoleptic properties have frequently led to its being taken for ethylic alcohol, generating numerous cases of methanol intoxication. In the fermentation and distillation processes of some alcoholic drinks/beverages, it can be found as a result of the degradation of the wood part of the along the distillation process. The sanitary norms limit the concentration of methyl alcohol in alcoholic drinks to a standard of 1%. This value is controlled for alcoholic drinks distilled in specialized firms, but it cannot be checked for drinks obtained by private producers at home, especially in the rural area. This type of products and the easy access to industrial products containing methanol have gradually led to intoxications. The toxicity of the methanol is given by formic acid which inactivates the ferric enzymes producing cellular anoxia and is also given by the untransformed fraction. As a consequence of the phenomena of cellular hypoxia, there is produced the metabolic acidosis with the increase of the anionic hole. This is a cumulative toxic substance. The toxic dose is of 0.15 mg/kg methanol 100%, the ingestion of 10 ml of methyl alcohol causes blindness and the lethal dose is of 30 to 60 ml. The symptoms of methanol intoxication starts with an inebriated state, followed by the increase of acidosis, hypotension, breathing condition leading to lung edema, digestive problems, agitation, convulsions. Eyesight problems install progressively. Acute and chronic intoxications can evolve into convulsive coma, hypotension, hypothermia, lung edema and death.
THE TROPHICAL SPECTRUM AND ROLE OF THE MAYFLIES (EPHEMEROPTERA) AND STONEFLIES (PLECOPTERA) IN TROPHICAL STRUCTURE OF MACROINVERTEBRATES COMMUNITIES OF BUZÃU RIVER
MAGDALENA - OANA RISTEA
Macroinvertebrates play an important role in material and energy transfer in aquatic ecosystem, being dominant in trophic structure of water flow. He food sourse, especially in lotic ecosystem, are distributed not uniform so as their location for feeding determined a series of morphological and behaviour adaptation. The approach of the macroinvertebrate feeding behaviour from a functional perspective permitted the understanding of the energetic flow dynamic from the aquatic ecosystem (Vannote et all., 1980). Macroinvertebrates give to the aquatic ecosystem many services as nutrients cycle and sediments aeration in this process of energy transfer maintaing. It was made a macroinvertebrates classification in accordance with the feeding macanism and functional and morphological adaptation in four feeding functional groups (Cummins and Klug, 1979): shreeder, scraper, collector and predator. Shreeders eat especially the periphyton fixed on the bottom, scraper eat vegetal and wooden parts (diameter >1 mm), collector eat fine organic particles, having specialized anatomic structures, predators can consume the whole prade or just their body containg. Mayflies and stoneflies have an important role in trophic structure of the nacroinvertebrates community. Fom the trophic level point of view, both groups have detritivores- herbivores species and stoneflies have also carnivorous.
CONTRIBUTIONS TO THE KNOWLEDGE REGARDING THE DISTRIBUTION OF CLERIDS (INSECTA: COLEOPTERA) IN ROMANIA
DANIEL KAZIMIR KURZELUK, NICOLAI CRACIUN
Although there are few in extenso articles in Romania on the distribution of beetles and only 2 catalogues [4, 10, 11], based on this and on the studied material a preliminary distribution can be traced. By the compilation of these recordings with the ones quoted in the literature it can be done an valid corellation with the western palaearctic chorotypes. By the interpretation of the obtained data we can establish the corotyp types and the faunal influences for every of the investigated species. The chorotype classification were taken from Taglianti et al.,1992 [14]. By the interpretation of the recording data in accord to this autor, it has became obviously that the romanian clerid fauna is formed mostly by western-palaearctic elements, the other types being less represented. An interesting presence is the species Allonyx quadrimaculatus Schaller, 1783, which has been recently recorded for the first time in our country [5]. From these data, we can conclude that its areal is not an discontinuous one, as believed until lately. The areal representation were done by dotted line, in these case, the authors having the same opinion with the conceotion of Bãnãrescu [2] and of Bãnãrescu & Boºcaiu [3], in accord with the quoted authors which affirm that the areal boundaries are not fixe and unsurpassable barriers.
ASPECTS REGARDING THE SOUND EMISSION AT RANA RIDIBUNDA PALL.
CIPRIAN RADU MÎNDRESCU
Sound emission in animal world is a means to perceive the surrounding environment, the space orientation, and the transmission of biological information. The analysis of the sound emissions at the anuras has a very important role (beside the morphological criteria) to the taxonomic identification. That is the reason for the characteristics of the amphibians’song are intensely studied lately. The investigations of the sound emissions were done at Bufonidae (9) and Hylidae (5, 6). Thus, the green frogs were carefully observed, because it is considered that their sound emissions allow a more precise identification of the species, especially of those from Rana esculenta complex (1 – 4, 7, 8, 10 – 14). Many scientific papers published recently refer to bioacoustic analysis (besides the traditional methods that investigate intra- and interspecific variability). This facts led us to initiate our study of sound emissions of Rana ridibunda Pall., free or in captivity, and to the determine their individual variability.