Assessment of bacteria and archaea levels in Çakalburnu Lagoon (İzmir) sediments by real-time PCR

Coastal lagoons are shallow water masses, discredited from the marines as a barrier that permits water to change through one or more inputs. These fragile ecosystems have a specific type of sediments with their own characteristics. Biogeochemical processes, mostly intervened by the benthic microbial loop, are significant for understanding the relationships among the lagoon and the contiguous coastal partition. This study was conducted in the Çakalburnu Lagoon (İzmir) area, which is located at the Bay of İzmir and the area covers 67 hectares. The aim of the present study is to constitute of determining the number of different microbial communities in the lagoon sediments. We collected from lagoon sediments samples at 7 stations and we applied a Real-time qPCR assay to determine levels of archaea (ARC), methanogenic archaea (MCRA), anaerobic methane oxidation archaea (ANME 1, ANME 2a, ANME 2c), bacteria (BAC) and sulfate-reducing bacteria (SRB2) in the study. The amount of maximum abundance of archaeal and bacterial 16S rRNA gene in sediments are 2,66x1010 gene copy numbers/g and 3,89x107 gene copy numbers/g, respectively. So, it was established that the archaeal abundance was intense in the lagoon sediments. The characterization of microbial diversity is significant for the comprehension of the biological fundamentals of the ecosystem. The data presented in our study contributes to the studies on preserving ecological and microbiological balance and determining biogeochemical cycles in sensitive ecosystems such as lagoons. The research will be conducted on studies to determine the abundance levels of seasonal and annual microbial groups in the future.

Innovation with Lagoon Sediments for Soil Conservation and Sustainable Intensification in the Ecuadorian Andes

Agricultural production outlines the constant antagonism between the quest to achieve the highest yields and the need to preserve the physical/chemical properties of soils. The constantly increasing global demand for food prompts producers to apply more agrochemicals in order to increase their production, generating soil degradation, which is a costly and complex issue to solve. Based on this context, we targeted a variety of objectives such as (a) to evaluate the effectiveness of lagoon sediments in soil recovery; (b) to analyze the effect of sediment on the yield of the coriander crop; and (c) to determine soil reclamation costs. The experiment was developed in the province of Imbabura, located in northern Ecuador. For this, we occupied a surface area per plot of 3 m2 and used a completely randomized block experimental design. Four doses of sediment were applied, being mixed with soil. The benefits of the use of lagoon sediments are evidenced in the nutritional quality of the soil after its application, determined by the physical and chemical analysis that reveals an increase of 3.9 ppm of the initial N, even after vegetative consumption. Similarly, the best electric conductivity (E.C) was 0.85 mS/cm, which promoted a higher crop yield compared to the control treatment, becoming an innovative alternative for soil recovery. This activity allowed reconciliation of the intensive agriculture with soil conservation.

X-ray Computed Tomography as a Tool for Screening Sediment Cores: An Application to the Lagoons of the Po River Delta (Italy)

Lagoon sediments have heterogeneous structure and texture, contain shells and plants and are often highly bioturbated and disturbed by human activities. In such sediments, the selection of representative cores and the choice of a subsampling strategy are important but difficult. In this study, we examine the usefulness of X-ray computed tomography (CT) for inferring sediment features that will help in making optimal decisions prior to core opening (24 cores from seven lagoons). Various algorithms (intensity projections, slice thickness, axial and sagittal images, CT number profiles and volumetric region of interest) are tested to visualise low- and high-density volumes or objects and to quantify the relations between the average volumetric CT number and the bulk density of the sediment matrix. The CT number is related mainly to water content and indirectly to total nitrogen and <16-μm grain-size fraction (model R2 = 0.94). The outliers are attributed to a weak correspondence between the fraction of sediment sampled for water content determination and the volume of sediment matrix used for CT number measurements in highly heterogeneous sediment slices. In conclusion, CT is a powerful tool for the initial screening of cores recovered from heterogeneous lagoon sediments. The adequate use of available algorithms may provide quantitative information on various sediment features, allowing the purposeful selection of cores and subsamples for further investigation.