The protist community mirrors seasonality and mesoscale hydrographic features in the oligotrophic Sargasso Sea

Protists represent the majority of the eukaryotic diversity in the oceans. They have different functions in the marine food web, playing essential roles in the biogeochemical cycles. Meanwhile the available data is rich in horizontal and temporal coverage, little is known on their vertical structuring, particularly below the photic zone. The present study applies DNA metabarcoding to samples collected over three years in conjunction with the BATS time-series to assess marine protist communities in the epipelagic and mesopelagic zones. The protist community showed a dynamic seasonality in the epipelagic, responding to hydrographic yearly cycles. Mixotrophic lineages dominated throughout the year; however, autotrophs bloomed during the rapid transition between the winter mixing and the stratified summer, and heterotrophs had their peak at the end of summer, when the base of the thermocline reaches its deepest depth. Below the photic zone, the community, dominated by Rhizaria, is depth-stratified and relatively constant throughout the year, mirroring local hydrographic and biological features such as the oxygen minimum zone. The results suggest a dynamic partitioning of the water column, where the niche vertical position for each community changes throughout the year, likely depending on nutrient availability, the mixed layer depth, and other hydrographic features. Finally, the protist community closely followed mesoscale events (eddies), where the communities mirrored the hydrographic uplift, raising the deeper communities for hundreds of meters, and compressing the communities above.

LAYOUT AND DESIGN SOLUTIONS OF FILTERING WATER INTAKES FROM SHALLOW WATERCOURSES FOR DRIP IRRIGATION SYSTEMS

Purpose: development of layout and design schemes for low-flow water intakes, arranged on shallow river and stream watercourses for supplying water to drip irrigation systems. Agricultural development of terraces and floodplains of small foothill and mountain streams actualizes the development of facilities for water intake from them for the purpose of irrigating land. Morphological and hydrographic features, including shallow low-water depths, high flow rates, flow rates variability, saturation with sediments, the presence of underflow and overflow runoff, etc., make water intake from such watercourses difficult and specific. These circumstances predetermine the relevance of water intake structures development corresponding to the specified conditions. Materials and Methods. When developing the layout and design schemes of low-flow water intakes from shallow watercourses, the technologies of exploratory design of engineering systems and structures were used. Results. With regard to the morphometric, hydrological and other conditions of shallow foothill and mountain streams, a water intake with a bottom water intake was adopted for development. The water intake part of headworks is designed in the form of a toe drain, which has under-flow and overflow intake parts that allow water intake from the channel and off-channel water streams. The toe is made of two or three layers of sand and gravel material. Drainage pipes or pipe filters are used as a drainage element. Depending on the conditions of the watercourse, water intakes with transverse, longitudinal and pocket-coastal placement of water intakes are proposed. Conclusion. The layout and design schemes of filtering water intakes from shallow watercourses based on the use of overflow, underflow and combined structures of multilayer drainage water intakes with stream (transverse and longitudinal) and off-channel (pocket-coastal) placement have been proposed and developed.

GIS Modeling of Meteorological and Hydrological Variables for the Purpose of Regional and Spatial Planning - Case Study of the City of Sarajevo

This study aims to combine a review of the main climatic and hydrographic features of the City of Sarajevo, which provide knowledge and insight into the basic principles of assessing climate and water potential of a particular geospace through GIS modeling of spatial data. This analysis acquired an application of current GIS modeling technologies and Remote Sensing technology in the valorization of hydro-meteorological variables of geospace.The study is conceived in two parts, one which refers to cartographic representations and explanations of the meteorological variables of the area of ​​the City of Sarajevo whilst the second part combines cartographic representations and explanations of important hydrographic variables of the observed geospace. For the purposes of this study, the following methods were used: analyzes, syntheses, statistical method, comparative method, and especially important cartographic ones, by which the previously analyzed objects were visually presented in the form of cartographic attachments.

Scale Optimization in Topographic and Hydrographic Feature Mapping Using Fractal Analysis

A new method for selecting optimal scales when mapping topographic or hydrographic features is introduced. The method employs rank-size partition of heavy-tailed distributions to detect nodes of rescaling invariance in the underlying hierarchy of the dataset. These nodes, known as head/tail breaks, can be used to indicate optimal scales. Then, the Fractal Net Evolution Assessment (FNEA) segmentation algorithm is applied with the topographic or hydrographic surfaces to produce optimally scaled objects. A topological transformation allows linking the two processes (partition and segmentation), while fractal dimension of the rescaling process is employed as an optimality metric. The new method is experimented with the two biggest river basins in Greece, namely Pinios and Acheloos river basins, using a digital elevation model as the only input dataset. The method proved successful in identifying a set of optimal scales for mapping elevation, slope, and flow accumulation. Deviation from the ideal conditions for implementing head/tail breaks are discussed. Implementation of the method requires an object-based analysis program and few common geospatial functions embedded in most GIS programs. The new method will assist in revealing underlying environmental processes in a variety of earth science fields and, thus, assist in land management decision-making and mapping generalization.

Biogeography of the Oceans

This chapter summarizes global patterns and mechanisms of both ecological and historical crustacean biogeography resulting in the contemporary species distributions described over the past decades. In the pelagic realm, hydrographic features such as ocean currents, physical depth profiles, and latitudinal temperature gradients are major structuring elements, as well as selection pressure exerted by the environment and species interactions, which have resulted in speciation over evolutionary time. Benthic crustacean distributions are additionally constrained longitudinally by continental barriers and submarine features such as ridges and seamounts. The main biogeographic patterns of both benthic and pelagic crustaceans are described for all ocean basins and the polar regions, of which the Indian Ocean is the least well studied. The Copepoda and Decapoda are generally represented with the highest number of described species, followed by Amphipoda and Isopoda. Life cycles with pelagic larvae (e.g., decapods and stomatopods) increase dispersal and enable wide distributions, while a lack of dispersive larvae promotes endemism in benthic forms (e.g., amphipods). Restricted regions with high species richness and endemism, such as the “coral triangle” (the Indo-Australian Archipelago), the Red Sea, and the Mediterranean, represent important biodiversity hotspots. Endemics are also suitable markers for past earth history events. Only a few studies cover the biogeography of crustacean taxa in all of the world’s oceans, but a few exceptions exist for decapods, amphipods, and isopods. Although the world’s oceans have been reasonably well studied for crustacean distribution and diversity, species complexes and cryptic species lacking morphological diagnostic features leave us with a large number of unconsolidated taxa. Emerging molecular tools may be able to assist with refinement of nomenclature and hence increase the resolution of crustacean biogeography in the future.

Horizontal and vertical distribution of cephalopod paralarvae in the Mesoamerican Barrier Reef System

Horizontal and vertical distribution of cephalopod paralarvae (PL) from the Mesoamerican Barrier Reef System (MBRS) in the Western Caribbean was studied during two oceanographic cruises in 2006 and 2007. A total of 1034 PL belonging to 12 families, 22 genera, 24 species, 5 morphotypes and a species complex were identified. Abralia redfieldi, Onychoteuthis banksii and Ornithoteuthis antillarum were the most abundant taxa. The taxonomic identification from these three species was corroborated with DNA barcoding (99.8–100% of similarity). Paralarvae of Octopus insularis were reported for the first time in the wild. Most PL occupied the Caribbean Surface Water mass in the 0–25 m depth stratum. Largest paralarval abundances were related to local oceanographic features favouring retention such as the Honduras Gyre and Cozumel eddy. No day-night differences were found in PL abundance, although Abralia redfieldi showed evidence of diel vertical migration. Distribution of PL in epipelagic waters of the MBRS was probably related to ontogenetic migration, hydrographic features of meso and subscale, and to the circulation regimes dominated by the Yucatan Current. The MBRS represents an important dispersion area for PL, potentially connecting a species-rich Caribbean community with the Gulf of Mexico and Florida waters.

Effects of Natural Geographic Features on the Manufacturing Industry in Sanliurfa, Turkey

Geographical features of a place have an important effect on distribution, location, aglomeration and a variety of industrial activities. Social and economical features, along with natural geographic features such as geology, geomorphology, climate, natural vegetation, soil properties and hydrographic features also have a significant effect on industry. This study aims at determining how physical geographic features affect categories of industrial activities in Sanliurfa. For this purpose, firstly, physical geographic features of Sanliurfa and statistical data on agricultural and industrial activities in Sanliurfa were obtained. Then, effects of these physical features on other economic activities and the influence of those features on the distribution of industrial plants and industrial activities were analysed in terms of distribution, relation and casuality principles. Geological formations in Sanliurfa province occured in Neogene and also in Quaternary. These formations mostly consist of Neogene limestone, Quaternary basaltic volcanic rocks and alluvial soils. Geomorfically Sanliurfa is a slightly hilly place with plateaus and plains. The main river in Sanliurfa is the Euphrates – the biggest river of Turkey. Naural vegatation of Sanliurfa consists of steppe. These physical geographic fetaures of Sanliurfa cause intensive agricultural activites all across the province. Sanliurfa province covers 18,584 km² and 60% of this area is convenient for agriculture. As a consequence, the majority of manucturing industry in Sanliurfa is agro-based, such as food, textile, mill and apparel industries. While these categories constitute 65.43% of all industrial enterprises, the share of enterprises involving stone, clay, glass, and concrete industry is 11%, and lumber and wood industry share is only 2%.