Seawater In Area Research Articles

Dynamics of the Spatial Chlorophyll-A Distribution at the Polar Front in the Marginal Ice Zone of the Barents Sea during Spring

Effects of the sea-ice edge and the Polar Frontal Zone on the distribution of chlorophyll-a levels in the pelagic were investigated during multi-year observations in insufficiently studied and rarely navigable regions of the Barents Sea. Samples were collected at 52 sampling stations combined into 11 oceanographic transects over a Barents Sea water area north of the latitude 75° N during spring 2016, 2018, and 2019. The species composition, abundance and biomass of the phytoplankton community, chlorophyll-a concentrations, hydrological and hydrochemical parameters were analyzed. The annual phytoplankton evolution phase, defined as an early-spring one, was determined throughout the transects. The species composition of the phytoplankton community and low chlorophyll-a levels suggested no phytoplankton blooming in April 2016 and 2019. Not yet started sea-ice melting prevented sympagic (sea-ice-associated) algae from being released into the seawater. In May 2018, ice melting began in the eastern Barents Sea and elevated chlorophyll-a levels were recorded near the ice edge. Chlorophyll-a concentrations substantially differed in waters of different genesis, especially in areas influenced by the Polar Front. The Polar Front separated the more productive Arctic waters with a chlorophyll-a concentration of 1–5 mg/m3 on average from the Atlantic waters where the chlorophyll-a content was an order of magnitude lower.

ВПЛИВ ФІЗИЧНИХ І ОКЕАНОГРАФІЧНИХ ФАКТОРІВ НА РОЗШИРЕННЯ ЗОНИ ЗАБРУДНЕННЯ КАСПІЙСЬКОГО МОРЯ (ПІВНІЧНО-СХІДНА ПРИБЕРЕЖНА ЗОНА АЗЕРБАЙДЖАНУ)

Aim. Our main goal is to study the spread of pollution caused by natural and anthropogenic factors in the water area of the Caspian Sea, the largest closed basin in the world, according to physical and oceanographic factors. The methodological basis of the article. The article uses methods of processing statistical indicators and selects the Brooks-Koch method to calculate the rise height (∆H0) of wastewater in a stratified environment. Results. In the water area of the Republic of Azerbaijan, the pollution of the Caspian Sea occurs mostly in the Absheron Peninsula. The main reason for this is that the area is rich in oil and gas reserves and there are many oil production enterprises. In addition to natural factors such as wind, temperature and currents, anthropogenic factors also influence the spread of oil-contaminated seawater. As a result of the analysis of the physical and oceanographic factors, we determined that the depth of sewage should be more than 70 meters when it is discharged into the sea. The main reason for this is that the sewage dumped in the depth is mixed with the cold, and with time, heavy bottom currents. As sewage mixed with clean seawater rises to the surface, it continues to mix in the intermediate layers because its weight is heavier than the layer above it. The main reason why this happens only in the Caspian Sea is that the temperature of the sea water increases instead of decreasing with depth. The fact that the turbulent mixing coefficient calculated for the area confirmed in the article is 104-106 shows that the concentration pulsation intensifies with the increase in the diameter of the sewage sludge. This situation creates conditions for the mixing of waste water with the surrounding water. Scientific novelty. The effect of physical and oceanographic factors on the change, expansion and deepening of the area of sewage in the Caspian Sea water area was studied. Also, the turbulent diffusion coefficient of pollution in coastal zones was calculated.

On the issue of international legal regulation of ensuring environmental safety in water transport in the Black Sea

This article studies the mechanism of protection of the Black Sea marine environment ensuring environmental safety in water transport in its water area, which was normatively consolidated in the 1992 Convention on the Protection of the Black Sea from Pollution. The article studies and describes the international and regional experience of regulating public relations arising from the provision of environmental safety, as well as proposals for improving international law in this area. The article presents the major research outcomes on the main measures aimed to introduce amendments to the current international law on regulation of public relations arising in the field of ensuring environmental safety in water transport in the Black Sea. Based on the analysis of the current international regional agreement in the area under consideration, the author has proposed some recommendations for its further development, and also highlighted the main areas to be regulated taking into account the need to conduct research in order to create the necessary rules and regulations that can ensure environmental safety in the operation of sea vessels. In order to improve the ecological situation in the Black Sea water area, it is necessary to amend the Convention on the Protection of the Black Sea against Pollution by introducing a number of special measures proposed in the article.

Integral assessment of the geodynamic conditions for the formation of the Black Sea basin and connection with the current regime of groundwater in its northwestern shelf

The paper has a multidisciplinary character connecting bathymetric, geophysical and geological information to innovatively reconstruct the geodynamic conditions of the Black Sea basin formation, their influence on the modern relief and groundwater regime within its northwestern shelf as a reference region. The major goal is the rationale of modern geodynamic settings for the Black Sea Basin against the back- ground of the processes of its closure under tangential compression conditions, as well as their relation- ship with the hydrogeological conditions of the shelf zone. As primary evidence, the author determined the spatial positions of the Constanta-Sinop and SubPontian Suture Zones, pinpointing absorption locations of the Earth's crust at subduction zones. The facts and arguments presented in this paper are well integrated into the scheme of the oncoming of the Pontides island arc to the Eurasian Plate and the gradual closure of the back-arc marginal Black Sea Basin with a crust of transitional-type crust. The specific feature of the study is an innovative approach to comprehensive analysis of data that are a result of geological and geophysical works within the Black Sea water area. In doing so, major attention is paid to the spatial morphostructural analysis and interpretation of newly integrated digital data array, as a result of bathymetric surveys, namely the EMODnet 2019—2022. The subject of analysis is the basic structural surfaces, including the Modern and on its margin consolidated basement. New justification is formulated on the confinement of gas seeps and mud volcanoes, within the Black Sea Basin, to the deep earth`s crust structures. The graphical correlation of the mentioned ones is performed as well as their spatial position in the structural-geodynamic model of the region is theoretically substantiated. A generalized geomorphological zoning of the northwestern shelf of the Black Sea with the identification of the Dobrogea, Odesa and Kalamit zone is proposed. Within the Odesa geomorphological region, an integrated geological and geomorphological analysis was carried out and, as a result, dividing the shelf into submarine groundwater discharge (SGD) zone of aquifer was substantiated. The study, carried out by the author is of crucial importance to understanding the tectonic and geo- dynamic characteristics of the Black Sea Basin as well as for forecasting SGD zones and fresh groundwater resources. It is recommended to set targeted prospecting works to assess fresh groundwater resources in order to meet the water needs of coastal communities.

Bioinformation of Blue Swimming Crab (Portunus pelagicus) during Covid-19 Pandemic in Bintan District, Riau Islands Province

Riau Islands Province has high fishery potential because it is surrounded by sea water areas. One of high potential of fisheries is blue swimming crab commodity. Covid-19 pandemic in the world has affected various sectors, one of which is the blue swimming crab sector, therefore biological information (bioinformation) during this pandemic very useful for blue swimming crab sustainability, especially in Bintan District. This study aimed at providing bioinformation related to blue swimming crab during the covid-19 pandemic in Bintan Regency. The bioinformation includes size distribution, growth patterns, sex ratios, and maturity level of female crab gonads in Kawal and Pengujan waters (Bintan Regency). The carapace width of the blue swimming crab in Kawal ranges from 102,2–187,9 mm and carapace width in Pengujan ranges from 106,3–148,4 mm. The carapace width class mode was found at the mean class value of 130 mm (in Kawal) and 140 mm (in Pengujan). The growth patterns of both female and male crabs in Kawal and Pengujan are negative allometric. Based on the chi square test with a confidence level of 95% (α = 0,05), the sex ratio of female-male blue swimming crab in general both in Kawal and in Pengujan was in a balanced condition. The level of gonad maturity in female blue swimming crab in Kawal and Pengujan was found from level of gonad maturity 1 to 4 stages. In Kawal found 67% were mature gonad, 22% immature gonad, and 11% berried female. In Pengujan found 31% were mature gonad, 63% immature gonad, and 6% berried females.

Profile of Leachate and Sea Water in The Waste Processing Area Suwung, Denpasar, Bali

This study aims to determine the profile of leachate, and seawater in the Suwung waste processing area (TPA Suwung). The method used in this research was descriptive quantitative. The results showed a high profile of untreated leachate with a TSS value of 9.407 mg/L, pH with a value of 8.17, DO with a value of 0.063 mg/L, BOD with a value of 375.5 mg/L, and COD with a value of 5.776 mg/L. The treated leachate with a TSS value of 4,987 mg/L, pH with a value of 8.52, DO with a value of 0.063 mg/L, BOD with a value of 321.9 mg/L, and a COD value with a value of 3.069 mg/L. Meanwhile, the seawater profile was classified as good with parameter values of TSS with a value of 76 mg/L, DO 7.54 mg/L, pH 7.54, BOD with a value of 13.6 mg/L, COD with a value of 64 mg/L. The existence of TPA Suwung has a negative impact and influence on seawater in the area. Revitalization efforts are needed to carry out leachate water treatment so that the effluent quality can be improved for the quality of water around TPA Suwung.

Innovative System for Controlling the Treatment and Disinfection of Sea Ballast Water: Danube Institute of National University “Odessa Maritime Academy”

This study is devoted to the threat to marine ecological safety associated with the presence of invasive alien species (IAS) in the World Ocean, which is among the global problems in today’s world. A number of port cities of Ukraine, such as Odessa, Izmail, Kherson, and Mykolaiv, significantly contribute to the pollution of the sea water areas with IAS. Invasive alien species that are present in sea water are supplied together with the latter into ballast tanks (to maintain balance, list, and stability of ships) and end up in the sea even after passing through the ballast cleaning system, thereby securing themselves in certain water areas and ceasing to play the sanitary role; on the contrary, they become pests, i.e., a threat to the World Ocean. There are also IAS examples depending on the countries of the World, i.e., their location. An analytical review of the ballast water management systems most famous all over the world is given, the prospects of their application for disinfection and purification of ballast water and their comparative characteristics are provided. On the basis of strict ballast water quality standard D-2 of the International Maritime Organization (IMO), scientists from the Danube institute of National University “Odessa Maritime Academy” (Izmail, Ukraine) have proposed and developed experimental innovative equipment for purification and disinfection of water ballast. Ballast water is analyzed on sea vessels entering the Izmail shipyard “Odessa Maritime Academy” for factory repair from various water basins of the World Ocean. All ships entering the factory for repairing are suppliers of ballast water samples. The constructive features of the laboratory facility allow one to study ballast water when the corresponding modules of the system pass at various speeds.

INSTITUTIONALIZATION OF THE RUSSIAN-UKRAINIAN CONFLICT OVER THE BLACK SEA

The purpose of the study is to determine the formal and informal practices of resolving conflicts between the Russian Federation and Ukraine over the use of the Black Sea water area. In this article, the author analyzed the problems of organizational forms for the settlement of Russian-Ukrainian claims over the Black Sea. The article assesses the effectiveness of the use of old institutions and the search vector for new non-institutional forms. The author substantiates his conclusions on the example of an armed incident near the Kerch Strait in 2018. Results. Against the background of the low institutional development of bilateral relations, the Russian Federation actually fulfilled certain requirements of Ukraine, which did not refuse to consider complaints and claims in international instances. Russian-Ukrainian conflicts are institutionalized and rationalized. Since there is no reciprocal initiative of the Russian authorities, Ukraine insists on holding forced negotiations on the basis of the current UN Convention on the Law of the Sea. This is hampered by the current bilateral Treaty between the Russian Federation and Ukraine on cooperation in the use of the Sea of Azov and the Kerch Strait in 2003.

Assessment of recreational potential of Sevastopol bays using bioindication methods

Aim. Study of a group of biochemical parameters of the hepatopancreas and gills of the Black Sea mussel Mytilus galloprovincialis Lam. and the functional indicator of cardiac system adaptivity of mussels from Sevastopol bays with different levels of recreational and anthropogenic impact.Methods. Mussels were collected from four Sevastopol water areas (Kruglaya Bay, Kazachya Bay, Matyushenko Bay and Cape Khrustalnii) in autumn 2018. The bioindication methods used were based on application of functional (cardiac system adaptability) and biochemical indicators (antioxidant enzymes activity [AEA], aminotransferases, the alkaline phosphatase [AP], and products of the lipid peroxidation [LPO] and protein oxidation [PO]) of mussel tissues. The hydrochemical parameters of the investigated areas were determined.Results. The anthropogenic impact on a complex of biochemical indicators of mussels at the sampling sites was shown. At the same time, low values of mussel heart rate (HR) recovery time (Trec) (less than 60 min.) in all sampling sites demonstrated the efficiency of biochemical changes in mussels and the possible use of all tested bays as recreational areas.Conclusion. Results of the present research allow the characterization of the ecological status of these Sevastopol sea water areas and to make recommendations about their rational use. Matyushenko and Kazachya Bays are most suitable for beach recreation and recreational fishery. Kazachya Bay also has favourable conditions for the development of water sports. Kruglaya Bay and Cape Khrustalnii are less ecologically safe and require a series of actions to improve water quality.

Analysis of Entropy of Temperature and Salinity Distribution in Subsurface Layer of the Kara Sea Water Area by Geomatics Methods

In recent years the nature of the Kara Sea is greatly influenced by human economic activity. It is stipulated mainly by extensive development of the Kara Sea coastline and by huge deposits of hydrocarbons on its shelf. An attempt to estimate the entropy of temperature and salinity distribution in subsurface layer of the Kara Sea water area has been made in this study aided by the newest geoinformational methods of study (Quantum GIS Desktop program complex). The computation and cartographic modeling of this problem show that the greatest values of entropy indices are registered within littoral and shelf regions. It can testify to the high diversity of these water areas and it is necessary that special (nature protection) regimes of nature use should be set up.

АНАЛІЗ СУЧАСНОГО СТАНУ ФУНКЦІОНУВАННЯ ПІДПРИЄМСТВ ВОДНОГО ТРАНСПОРТУ УКРАЇНИ ТА СВІТУ

This article is dedicated to the study of the market of freight and passenger transportation by water in the world and Ukraine in order to identify the prevailing trends in the industry. The statistical data and scientific works of domestic and foreign scientists on the current functioning and prospects of water transport were the main basis of the study. The authors analyzed the volume of freight transport by water, identified the main transportation routes and the distance thereof, and the development of maritime transport in different countries was analyzed as well. In the course of study the components affecting the efficiency of water transport enterprises, and generate the indicators of the development rate thereof in particular countries. It is established in this work that it is possible to assess the state of development of Ukrainian maritime transport on a global scale using the Global Competitiveness Index, which is generated according to the methodology of the World Economic Forum, in particular, water transport is assessed on two indicators: integration into the international transportation routes and port efficiency. The authors performed a comparative analysis of the Global Competitiveness Index in different countries, which convincingly proves the need for development of transport infrastructure of a state, which is part of the overall infrastructure development in the country. In this work the main problems of the transport industry development are identified, the factors of negative impact on the state and prospects of river and maritime transport enterprises of Ukraine, including obsolescence or lack of navigational infrastructure, and lack of a systematic approach to water logistics construction, and obsolescence and insufficiency of the fleet, and the lack of qualified personnel in the industry, as well as the lack of state regulation and the lack of state support; unsatisfactory investment climate in the country as a whole, the complexity of registration and high cost of international cabotage in both sea and river water areas of Ukraine, etc. The authors substantiated the ways of counteracting the identified factors and defined the directions of development of water transport enterprises, as well as measures proposed separately for river and maritime transport.

ОСОБЕННОСТИ БИОТОПИЧЕСКОГО РАСПРЕДЕЛЕНИЯ ГНЕЗДЯЩИХСЯ ПТИЦ КАРАДАГСКОГО ПРИРОДНОГО ЗАПОВЕДНИКА (КРЫМ)

The article gives a classification of biotopes and analyzes the features of the biotopic distribution of nesting birds of the Karadag nature reserve (2874.2 hectares), located in the extreme east of the Main ridge of the Crimean Mountains and including the Karadag mountain group (2065.1 hectares) with the adjacent Black Sea water area (809.1 hectares). On the basis of previously developed schemes and taking into account our own research, the following main types of habitats were identified: 1) natural tree and shrub vegetation; 2) open grassy biotopes; 3) rocky landforms; 4) seashore (except for rocky forms); 5) anthropogenic biotopes. Seventy-nine bird species were recorded nesting in the reserve. Ornithocomplex of natural wood and shrub communities includes 52 species, including 40 in oak open woodlands, 21 in juniper open woodlands and 32 in forests. The ornithocomplex of rocks (13 species: 9 on seaside rocks and 10 on off-shore cliffs) is characterized by high specificity as 9 species nest exclusively in these biotopes. The ornithocomplex of open herbaceous habitats is depleted and sparsely specific (10 species, most of which are common with sparse woodlands). The species composition of nesting birds of the sea coast (ground cliffs in bays, beaches with coarse material) is extremely poor (2 species). Thus, the basis of the nesting avifauna of the reserve is formed by the species of tree-shrub and rocky biotopes (in total, 82,3 % of the species composition). These ornithocomplexes include 67–89 % of the species composition of the corresponding habitats in the eastern part of the Mountainous Crimea. On the other hand, the small area, peripheral location and isolation of the Karadag mountain group resulted in the absence of a number of rare species in these biotopes and the low abundance of some species common and numerous in other regions of Eastern Crimea. At least 37 species (46,8 % of nesting avifauna) use anthropogenic biotopes – forest plantations (21 species), park (18), buildings (11), freshwater reservoirs (2). Ten species listed in the Red Data Books of the Russian Federation (7) and Crimea (9) nest in the reserve. Most of them (7 species) inhabit rock and rock-coastal biotopes, including 4 species nesting on coastal cliffs of the Beregovaya ridge. The role of the reserve is significant for preservation of Phalacrocorax aristotelis (about 10 % of the Crimean population) and Falco peregrinus (about 7 %).

Картографирование экосистемных услуг национального парка Колхети (Грузия) на основе их эколого-экономической оценки

The research area—the Kolkhety National park (Georgia)—is situated in the western part of the Kholhida lowland and includes coastal waters of the Black Sea. It was established in 1998, but its economic value was not assessed. The purpose of the work was to identify the ecosystem services of the park’s geosystems, to carry out an ecological-economic assessment of part of the ecosystem services, and to create map of ecological-economic assessment, which is necessary for its nature management regulation, including its buffer zones, as well as nature conservation and recreation activities. Using our field data and thematic publications we compiled a map, presenting 4 large areas of ecosystems: the Kolkhida woodlands, wetlands, the lake Paleostomi, the Black Sea water area. 25 ecosystem services were identified within them. The following were among them: resource ecosystem services—provision of feed for cattle, commercial products of water bodies, etc.; regulating—creation of the coastal line, wetlands water filtration, etc.; supporting—carbon deposition by terrestrial and aquatic ecosystems; information—recreation services. Information data base was compiled for several of them and used for assessments based on the widely used international methods. The assessment result of only seven ecosystem services demonstrated their cost—10.5 mln dollars annually. The results of ecological-economic assessments were used for compiling of an ecological-economic map presenting spatial distribution of different ecosystems services costs. The results may be used for the Georgian coastal area territorial planning and demonstrate the economic value of nature protected lands.

Influence of water area depth on wind waves

A semi-empirical technique for calculating the parameters of wind waves at variable sea depths along the wind acceleration has been developed and presented. This technique allows you to determine the average values of wind wave heights, their length and period depending on the wind velocity, taking into account and without taking into account the heaping of water by wind. Within the framework of the described method, the calculations of wind wave parameters suitable for isobaths d = 20 m were performed for a specific study area of the Bistre (Novostambulske) branch of the Danube estuary, for the north-eastern and eastern wind directions. Numerical simulations were performed for the Black Sea in the location of the protection dam of the Maritime approach channel of the Danube-Black Sea deep-sea navigation. Numerical calculations of wind wave transformation in the water area near the protection dam for the most dangerous wind directions in stormy conditions were performed. For mathematical simulation, the maximum values of wind velocity and wave height were used, which were observed during the whole period of research of the Black Sea water area in the region of the dam. Within the framework of refraction theory, wave transformation calculations have been performed for the most wave-hazardous wind acceleration directions, namely, the north-eastern and eastern wind directions. It is shown that taking into account the heaping of water by wind leads to an increase in the parameters of gravitational waves. The results of numerical simulations have shown that with the increase of wind acceleration exceeding the limit values, the parameters of the waves reach constant values. These values depend on the bathymetry of the seabed, wind velocity and direction. It was found that the increase in the deviation of the free surface of the sea from the undisturbed level significantly depends on the heaping of water by wind. It was found that the relative increase in the wave parameters is observed higher in the east wind direction than in the northeast wind direction in the study area of the Black Sea.

Seismogeological characteristics, model of geological structure and oil and gas potential of the Laptev Sea shelf

Analysis of seismic cross sections in the Laptev Sea showed that a sedimentary basin is developed in the western part of the water area, the thickness of platform deposits in which is 15–20 km. A complex interpretation of geological and geophysical materials on the continental margin of the Siberian platform and the Laptev Sea water area was carried out, seismogeological models of sedimentary complexes on the continent and in the sea were compared, and gravity and magnetic anomalies were analyzed. The research results showed that the western part of the Laptev Sea, in geological terms, is a northern continuation of the Siberian platform. The oil and gas potential of this part of the water area will be associated with the Upper Proterozoic-Middle Paleozoic carbonate deposits and Permian-Mesozoic terrigenous sedimentary complexes.

All-Electric Subsea Control Systems and the Effects on Subsea Manifold Valves

Subsea development is moving constantly toward simplification, digitalization, and cost-out strategies because the exploration and production of hydrocarbons are moving toward deeper and remote sea water areas. Usage of all-electric subsea technology instead of hydraulic technology is growing and will be the future of subsea systems due to the former’s environmental and functional advantages and reduced costs. The benefits of all-electric subsea systems are health, safety, and environment (HSE) and improved reliability, flexibility, and functionality compared with traditional hydraulic-electrical systems. Existing electrohydraulic technology for a typical subsea system, hydraulic and electric actuators, and subsea manifold valves including valve types and selection philosophy have been reviewed in this paper. Some major worldwide oil companies such as Equinor and Schlumberger have successful experiences with subsea electric actuators. Considering the benefits of all-electric technology especially in terms of cost and HSE, as well as successful experiences of two major oil companies, further research in this area is warranted. One of the gaps in existing reviewed literature is the effect of using all-electric actuators for manifold valves. Thus, three main questions related to electric actuator selection, requirement of safety integrity level (SIL), and effect of using electric actuators on manifold valve selection have been addressed and answered. Forty hydraulic actuated manifold valves from nine past subsea projects in different parts of the world, mainly Africa and Australia, have been selected for the analysis of all-electric actuators. Results show that 93% of the valves require spring-return electric actuators, whereas 7% can be operated with conventional electric actuators without any spring. The manifold valves do not require SIL certification because they are not connected to an emergency shut down system. Introducing the electric actuators to the manifold valve will not change the valve selection philosophy.

Potensi Vegetasi Hutan Mangrove untuk Mitigasi Intrusi Air Laut di Pulau Kecil

<strong>Mangrove Forest Vegetation Potency to Mitigate Seawater Intrusion on Small Island. </strong>Natural resources exploitation in the coastal areascaused serious problems for shallow ground wateravailabily especially in small islands. Small islands society such as in Ambon Island facesdrinking water quality degradation due to the sea water intrusion.Mangrove is one of the coastal ecosystemtypesthatis though to minimize sea water intrusion.However, the information about mangroveparametersthat can be used todetermine the mangrove forest patches potency in small islands to mitigate sea water intrusion is still limited. The aim ofthis study is to assess the correlationof mangrove vegetation and sea water intrusion using transect anddipole-dipole configuration geoelectric methods. The study showed that the thickness of mangrove vegetation and the size of mangrove trees determined the mangrove forest potencyto mitigatesea water intrusion.There was no sea water intrusion (relativity values:75.5-118 Wm)in Passo, due to thick mangrove vegetation (mean:320 m) and bigmangrove tree sizes (mean diameter: 19cm and mean height: 10m).Sea water intrusion was low (relativity values: 0.798-4.53Wm)in Poka due to thin mangrove vegetation (mean 10-100 m) and small tree sizes(mean diameter: 8.6cm and mean height: 5m). In contrasts, sea water intrusion was very high (relativity values: 1.4-9.2Wm) for the areas without mangrove vegetation(e.g. Lateri). These mangrove parameters were also negatively correlated with the distribution and coverage area of sea water intrusion.Mangrove patches in small islands can be used assea water intrusion mitigation tools, but theecosystem condition was already degraded or in the poor conditions. The findings of this study are useful for government as a basis in decision makingand to better manage of ground water and coastal ecosystem particularly mangrove.

Diverse downstream migration patterns of the anadromous Japanese grenadier anchovy Coilia nasus in the Chikugo River estuary and Ariake Sea, Japan

Variations in the downstream migration patterns of the anadromous Japanese grenadier anchovy Coilia nasus in the Chikugo River estuary and the inner part of the Ariake Sea, Japan were investigated using otolith Sr:Ca ratios over life history transects. Although most individuals migrated from freshwater or low salinity areas (i.e., upper estuary; salinities <10) to brackish water or sea water areas (i.e., lower estuary or sea), the timing of the downstream migration was considerably different among individuals. Based on the otolith Sr:Ca profiles, four migratory groups were distinguished and their mean standard length (SL) at the initial downstream migration were inferred: (1) the Late Migration Group (LMG), in which individuals remain within freshwater or low salinity areas, where the estuarine turbidity maximum (ETM) is well developed at salinities <10, during the larva and juvenile stages until initial downstream migration at a size of 154 mm in SL; (2) the Early Migration Group (EMG), in which individuals immediately migrate from freshwater or low salinity areas to relatively high salinity brackish water areas at the early juvenile stage (45 mm in SL); (3) the Middle Migration Group (MMG), in which the initial downstream migration of the fish occurs at 90 mm in SL; and (4) the Brackish-Sea water Resident Group (BSRG), in which individuals are hatched in relatively high salinity brackish water areas and spend time there during the early life period. The relative contribution of the LMG and BSRG to adult females were low, whereas adult females were dominated by the EMG and MMG (72.4% of n = 58). Based on previous studies and our current results, C. nasus may greatly depend on the ETM zones during the early life stage, but there are significant differences in the timing and downstream migration patterns of C. nasus.

Karakter Anatomi Daun sebagai Bentuk Adaptasi Tumbuhan Penyusun Zonasi Mangrove di Banggai Kepulauan, Provinsi Sulawesi Tengah

Mangrove is an essential ecosystem that are located in the transition area of fresh and sea water. Therefore, species that grow are typical species that are able to adapt to the saline environment. The aim of this research is to characterize leaf anatomical structure for every species that compose the communities found in each mangrove zonations, including their similarities and dissimilarities characteristic. Sampling of examined leaf was carried out in the mangrove areas of Peling Island and Bakalan Island by making plots in four sites of the mangrove ecosystem area. Methods for leaf anatomical preparations were carried out using the paraffin-tert-butanol and paradermal sections. Anatomical characters as an adaptation to saline habitat are found in all species of mangrove plants, including thick cuticle and epidermal cells, thick leaves and water-storage tissue (hypodermis). In addition, there is found the presence of cork warts and sclereid as characteristic of the genus Rhizophora. Based on quantitative character observations, the mesophyll (palisade to sponge) ratio range from 0.28 ± 0.04 μm to 1.19 ± 0.42 μm, leaf thickness ratio 289,41 ± 38,21 μm to 695,20 ± 97,50 μm and the highest stomata density is owned by Lumnitzera littorea

Opredelenie mestopolozheniya nachal'nogo polya kontsentratsii vozmozhnogo istochnika zagryazneniya v akvatorii Chernogo morya u Gerakleyskogo poluostrova na osnove metoda sopryazhennyh uravneniy

Opredelenie mestopolozheniya nachal'nogo polya kontsentratsii vozmozhnogo istochnika zagryazneniya v akvatorii Chernogo morya u Gerakleyskogo poluostrova na osnove metoda sopryazhennyh uravneniy