Effects of cage fish farming on phytoplankton community structure,biomass and primary production in an aquaculture area in the middle Adriatic Sea     

Sanda Skejić  Ivona Marasović  Olja Vidjak  Grozdan Kušpilić  Živana Ninčević Gladan  Stefanija Šestanović  Natalija Bojanić 《Aquaculture Research》2011,42(9):1393-1405

In this study, we investigated the physical, chemical and biological parameters of the water column at two stations under different trophic conditions during a 1‐year period (from September 2005 to September 2006) in an aquaculture area. The investigation was performed monthly at a station inside the fish farm in Maslinova Bay (middle Adriatic Sea, Croatia) and at a control station located in the Hvar Channel in the vicinity of the farm. The results showed that the concentrations of dissolved nutrients were slightly enhanced at the farm station in comparison with the control station, although those differences were not statistically significant, nor were the differences in oxygen saturation recorded during the investigation period. As opposed to the chemical parameters, considerably higher deviations were recorded for biological parameters as demonstrated by a significant increase in phytoplankton biomass and primary production (measured in situ) at the farm station, particularly during the summer season. Phytoplankton community structure analysis showed that the phytoplankton composition at the farm was mostly determined by seasonal changes rather than by the influence of fish farming. In Maslinova Bay, no causal links were identified between increased biomass and the appearance of toxic species.  相似文献   

The Effect of Intravalvular Liquid Loss on Changes in Escherichia coli Levels in Live,Refrigerated Mussels (Mytilus galloprovincialis)     

Slaven Jozić  Katarina Milanković  Tea Brajčić  Mladen Šolić  Danijela Šantić  Marin Ordulj 《Journal Of Aquatic Food Product Technology》2017,26(4):491-500

We investigated the effect of intravalvular liquid loss on changes in Escherichia coli (E. coli) levels in mussels (Mytilus galloprovincialis) harvested in different seasons and refrigerated (5°C) for 72 hours. A positive effect of seawater temperature at the time of harvesting on intravalvular liquid loss was found. No changes in E. coli levels in mussels (flesh and intravalvular liquid), as the result of intravalvular liquid loss, were observed. Levels of E. coli in the flesh decreased, probably as a result of cells dying off, causing the maintenance of E. coli levels in flesh and intravalvular liquid to be stable throughout storage.  相似文献   

Aluminium and iron oxides affect the soil structure in a long-term mineral fertilised soil     

Šimanský  Vladimír  Jonczak  Jerzy 《Journal of Soils and Sediments》2020,20(4):2008-2018

Journal of Soils and Sediments - The influence of iron and aluminium (hydr)oxide on soil aggregation is still not sufficiently understood. Therefore, we undertook a study on the effects of Al and...  相似文献   

Nonnenkontroll -und Vorbeugungsmethode nach Professor Forst.-Ing. Ant. Dyk.     

Ing. Dr. Octavianus Farský 《Journal of pest science》1938,14(6):65-67

Ohne Zusammenfassung Mit 3 Abbildungen.  相似文献   

Biological and chemical properties of arable soils affected by long-term organic and inorganic fertilizer applications   总被引：17，自引：0，他引：17  

M. Šimek  D. W. Hopkins  J. Kalčík  T. Picek  H. Šantrůčková  J. Staňa  K. Trávník 《Biology and Fertility of Soils》1999,29(3):300-308

 Using soils from field plots in four different arable crop experiments that have received combinations of manure, lime and inorganic N, P and K for up to 20 years, the effects of these fertilizers on soil chemical properties and estimates of soil microbial community size and activity were studied. The soil pH was increased or unaffected by the addition of organic manure plus inorganic fertilizers applied in conjunction with lime, but decreased in the absence of liming. The soil C and N contents were greater for all fertilized treatments compared to the control, yet in all cases the soil samples from fertilized plots had smaller C:N ratios than soil from the unfertilized plots. The soil concentrations of all the other inorganic nutrients measured were greater following fertilizer applications compared with the unfertilized plots, and this effect was most marked for P and K in soils from plots that had received the largest amounts of these nutrients as fertilizers. Both biomass C determined by chloroform fumigation and glucose-induced respiration tended to increase as a result of manure and inorganic fertilizer applications, although soils which received the largest additions of inorganic fertilizers in the absence of lime contained less biomass C than those to which lime had been added. Dehydrogenase activity was lower in soils that had received the largest amounts of fertilizers, and was further decreased in the absence of lime. This suggests that dehydrogenase activity was highly sensitive to the inhibitory effects associated with large fertilizer additions. Potential denitrification and anaerobic respiration determined in one soil were increased by fertilizer application but, as with both the microbial biomass and dehydrogenase activity, there were significant reductions in both N₂O and CO₂ production in soils which received the largest additions of inorganic fertilizers in the absence of lime. In contrast, the size of the denitrifying component of the soil microbial community, as indicated by denitrifying enzyme activity, was unaffected by the absence of lime at the largest rate of inorganic fertilizer applications. The results indicated differences in the composition or function of microbial communities in the soils in response to long-term organic and inorganic fertilization, especially when the soils were not limited. Received: 10 March 1998  相似文献   

Effect of soil chemical properties on growth,foliation and nutrition of Norway spruce stand affected by yellowing in the Bohemian Forest Mts., Czech Republic     

Stanislav Vacek  Michal Hejcman  Věra Semelová  Jiří Remeš  Vilém Podrázský 《European Journal of Forest Research》2009,128(4):367-375

In 1998, a fertilizer experiment aiming to investigate the effects of slow-release N, P, K and Mg fertilizer (SILVAMIX Mg NPK^®) on a 60-year-old spruce stand with symptoms of yellowing was established. In this paper, trees were selected to investigate the relation between annual diameter increment, yellowing, foliation, needle and soil chemical properties: ten from the fertilized treatment (F), ten green trees from the control (CG) and ten yellow trees from the control (CY). CG and CY trees were growing in close proximity at a distance of only several meters apart under the same soil conditions. In treatment F, increased annual diameter increment, improved foliation, needle Mg concentration, plant-available Mg and P concentrations in the soil and absence of yellow trees were recorded 7 years after a single application of the fertilizer. During the last 15 years, annual growth increment and foliation of CY trees have continuously decreased while relatively stable values were recorded for CG trees and increased for F trees. In 2006, CG and CY trees differed significantly in Mg concentration in needles, foliation, yellowing and annual diameter increment. Although differences in soil chemical properties between CG and CY treatments were not significant, lower concentrations of plant-available Mg²⁺ and higher concentrations of H⁺ and Al³⁺ were found in soils under CY trees. There was a negative correlation between soil concentration of Mg and yellowing, but this correlation was relatively weak, indicating that there is no simple relation between soil and needle concentrations of Mg. In the investigated locality, the “new type” of yellow tree decline has been a long-term gradual process.  相似文献   

Effects of fish farming on microbial planktonic communities in the middle Adriatic sea          下载免费PDF全文

Stefanija Šestanović  Jelena Peković  Slavica Matijević  Živana Ninčević Gladan 《Aquaculture Research》2016,47(4):1040-1054

The effects of farming on planktonic microbial communities were investigated at the coastal sea bass/sea bream farm in the oligotrophic middle Adriatic Sea. Analyses of nutrients, chlorophyll a, cyanobacteria (Prochlorococcus), heterotrophic bacteria and nanoflagellates (both pigmented and heterotrophic) were carried out on samples taken during six seasonal cruises at different water depths. Farming activity increased the natural concentrations of some nutrients (ammonium, nitrite, phosphate, dissolved inorganic nitrogen) and changed their seasonal pattern. The values still remained typical for oligotrophic environ‐ments demonstrating no risk for eutrophication. Enhanced nutrient supply provoked an immediate increase in abundances of both autotrophic and heterotrophic microbial groups (except pigmented nanoflagellates) and chlorophyll a. The effect of farming was more visible for the heterotrophic microbial component. Results from this study reveal a potential common pattern of microbial response to farming in the oligotrophic environments. It also suggests the importance of heterotrophic microbial web in transferring the matter and energy released from the fish farms in nutrient poor environments.  相似文献