Condition Of Sea Research Articles

A semiparametric Bayesian method with birth-death Markov Chain Monte Carlo algorithm for extreme mooring tension analysis

A series of 1: 50 model tests have been conducted to study the dynamics of a taut mooring system and two hybrid mooring systems attached to a deep-water semi-submersible in the 100-year wave condition of the South China Sea. Three typical environmental conditions were tested, including head sea, beam sea and quartering sea. The mixture Gamma- Generalized Pareto distribution (GPD) model is applied to study short term extreme dynamic mooring tensions based on the measured data, the results are compared with the estimations from mixture Gamma and two-parameter Weibull models. A birth-death Markov chain Monte Carlo (MCMC) sampling procedure is developed to fit the parameters of a mixture Gamma- GPD via Bayesian inference, and an extensive discussion of the de-clustering procedure, parameters of the prior distribution for threshold and MCMC iteration steps on Bayesian inference are carried out. It is found that the Weibull model underestimates the most probable largest dynamic mooring tensions. On the contrary, the mixture Gamma model overestimates the extreme dynamic mooring tension significantly. The mixture Gamma- GPD can present good estimations of extreme dynamic mooring tension, and its performance is robust to the sample definition, MCMC iteration steps and parameters of threshold prior distribution.

Reliability analysis of Tension-Leg Platform Tendon with Respect to Fatigue Failure under Environmental Condition of Caspian Sea

Reliability analysis of Tension-Leg Platform Tendon with Respect to Fatigue Failure under Environmental Condition of Caspian Sea

ОРГАНІЗАЦІЯ ЕКОЛОГІЧНОГО МОНІТОРИНГУ У ВІЙСЬКОВО-МОРСЬКИХ СИЛАХ ЗБРОЙНИХ СИЛ УКРАЇНИ

The purpose of this article is to substantiate the need to create an environmental monitoring system in the Ukrainian Navy.The object of research of this article is to study the possibility of creating a system of environmental monitoring in the Ukrainian Navy. The subject of research is the system of environmental monitoring in the Ukrainian Navy. The scientific task of the work is to provide a justification for the creation of an environmental monitoring system in the Ukrainian Navy, based on the trends of increasing man-made pressure on the Black Sea ecosystems. To achieve this goal in this work solved the following individual tasks: the tendencies of deterioration of an ecological condition of the Black Sea are resulted; the analysis of currently existing types of environmental monitoring, taking into account their shortcomings; recommendations were provided on the establishment of an environmental monitoring system in the Ukrainian Navy. The above individual problems were solved on the basis of the analysis of literary sources on military, ecological and oceanographic topics. Recommendations on ways to create an environmental monitoring system in the Ukrainian Navy, which will allow researchers to assess the impact of the Ukrainian Navy on vulnerable ecosystems of the Northwest Black Sea to make appropriate management decisions in the field of nature. The article proposes the creation and implementation of a new system of environmental monitoring of the Ukrainian Navy (SEM Navy) and its inclusion in the system of monitoring the environmental condition of the Black Sea. The implementation of the SEM Navy will control the impact on the environment, predict changes in environmental parameters and harmonize the interaction of the Ukrainian Navy and nature. Keywords: Navy, ecological monitoring, forecasting, ecological condition.

Geochemistry of carbonate rocks of the Chilpi Group, Bastar Craton, India: Implications on ocean paleoredox conditions at the late Paleoproterozoic Era

The chemogenic sediments of the Chilpi Group (~2.0–1.8 Ga) of the Bastar Craton have been analysed for the sedimentary environment, geochemistry and redox evaluation of seawater towards the end of the Paleoproterozoic Era. Fabric-retentive fine-grained micritic and oolitic carbonates suggest preservation of primary texture and precipitation from contemporaneous seawater in a shallow water tidal environment. Reducing condition of shallow sea for the Chilpi Group is also recognized by the presence of chamosite associated with Mn-ankerite. The Post-Archean Australian Shale (PAAS) normalized positive Gd and La anomalies, Lu/La, Y/Ho molar ratios and the Y anomaly indicate the preservation of pristine marine nature of the carbonates. Evaluation of multi-element concentration indicates no significant effects of detrital contamination, diagenesis, metamorphism and contributions from hydrothermal sources. Positive Ce anomalies observed in all the samples, with maximum Ce/Ce* up to 2.83, and redox responsive trace element ratio patterns in association with enrichment of Mn and other redox responsive elements such as Zn, Fe, Mo and U indicate a reducing marine environment of deposition of the Chilpi carbonates. Display of positive europium anomalies (Eu/Eu* = 1.02 – 1.56) can be attributed to the reducing environment as contributions of hydrothermal fluids are ruled out for lack of LREE enrichment compared to HREE. We infer suboxic to anoxic conditions of shallow sea in the Chilpi basin towards the end of the Paleoproterozoic Era, with estimated atmospheric oxygen level of ~10-3 PAL. Reducing conditions in shallow sea indicate that the Great Oxidation Event did not affect seawater composition during late Paleoproterozoic.

Analisis Parameter Fisika-Kimia untuk Kepentingan Rehabilitasi Ekosistem Mangrove di Pesisir Pulau Bungkutoko Kota Kendari

In Southeast Sulawesi rehabilitation of mangrove areas that have been damaged but in reality not all mangrove rehabilitation activities were successful, this was allegedly caused by a mismatch in the type of mangrove and incompatibility of rehabilitation techniques used with environmental conditions or parameters of the local coastal environment. This study is aimed to analyze the condition of coastal environmental parameters in Bungkutoko island, district of Abeli in rehabilitation proposed of mangrove ecosystem and to find a proper rehabilitation strategy for it can be applied in that area. This study was carried on June to July 2009 in the coastal of Bungkutoko island, Abeli district, Kendari Town. Data in this study is analyzed as descriptively for giving common view of that area. The measurement results of several physical-chemical parameters on the coast of Bungkutoko island at stations I, II and III are suitable for mangrove ecosystem rehabilitation activities, which have a slope of the base: flat and sloping, particle size: small substrate, binding capacity of substrate particles: moderate to loose, confinement coastline: protected and semi protected and open, wave: relatively small, sea level deviation: moderate, tidal type: mixture tends to double daily, current speed: weak, sediment suspension: normal and salinity: 25-35 ppt. Also pay attention to the right planting time on the condition of mangrove tree is in having fruits and calm water condition of sea. And for planting technic is propaguls directly planted to the ground and using seeds on the polybags.

ANALISIS PARAMETER FISIKA-KIMIA UNTUK KEPENTINGAN REHABILITASI EKOSISTEM MANGROVE DI PESISIR PULAU BUNGKUTOKO KOTA KENDARI

Abstract
 In some places rehabilitation of mangrove areas that have been damaged but in reality not all mangrove rehabilitation activities were successful, this was allegedly caused by a mismatch in the type of mangrove and incompatibility of rehabilitation techniques used with environmental conditions or parameters of the local coastal environment. This study is aimed to know the condition of coastal environmental parameters in Bungkutoko island, district of Abeli in rehabilitation proposed of mangrove ecosystem and to find a proper rehabilitation strategy for it can be applied in that area. This study was carried on June to July 2009 in the coastal of Bungkutoko island, Abeli district, Kendari Town. Data in this study is analyzed as descriptively for giving common view of that area. Results of some parameters measured in the area are showed as topographies are 0,1 %, 3 %, 3,2 % for Station I, Station II and Station III, respectively. Substrate particles is more small, and it adhesive force in Station I and II is same medium, and Station III is free. Shoreline of Station I as covered and Station II and Station III are semi covered. The High of waves are 7-17 cm and 8-22 cm for Station II and Station III, as respectively. Fluctuation of tidal is middle, and the tidal type of the shoreline is mix to be diurnal. Water current in all station are Station I = 0,01-0,05 m/s, Station II = 0,01-0,08 m/s, Station III = 0,02-0,1 m/s. Suspension sediments of all stations are 1,97 mg/l, 3,96 mg/l, and 3,10 mg/l for Station I, Station II, Station III, respectively. Salinity in range of 25-35 ppt, and both Station II dan Station III is same ranged on 30-35 ppt. In results of measured some physic-chemical parameters of coastal in Bungkutoko island is suitable for rehabilitation practice of mangrove ecosystem by concern of planting time on the condition of mangrove tree is in having fruits and calm water condition of sea. And also for planting technic is propaguls directly planted to the ground and using seeds on the polybags.

The Importance of Nutrients Concentration Monitoring In Coastal Area

Land utilization changes of the natural resources conservation area of Pangandaran coastal area, that have been utilized as a marine tourism area, which affect many kinds of environmental degradation threats. Updating the condition of Pangandaran waters is essential due to its condition impacted by anthropogenic activities. Water condition monitoring was done by measuring nutrients as an indicator to assess the water fertility and pollution. Fourty five observation points were selected and divided into three locations, representing the condition of river, estuary/mangrove area, and open sea. Nutrients were analyzed by employing Standard Methods for The Examination of Water and Wastewater 22nd Edition 2012 (SMEWW). Currents and tides were measured for 15 days, used as the basis input of hydrodynamic model. The results showed that the highest of average value of nitrate was found in the estuary/mangrove forest which reached 0.998 mg.L-1. While, the highest phosphate content was observed in the river which reached 0.928 mg.L-1. The highest ammonia concentration was observed in the sea which reached 0.027 mg.L-1. N:P ratios in the study area are categorized <16, which showed that Pangandaran waters are in the condition of N-limitation. These conditions trigger blooming of phytoplankton due to the high concentration of nitrate. The higher nutrient concentration indicates that anthropogenic activities take place. Tidal current has an important role transporting nutrient in the estuary, triggering nutrient deposition and blooming tendency. Restrictions on residential areas and the utilization of coastal areas are an appropriate step to reduce the pollution level in Pangandaran waters.

Influence of regional environment in guiding the spatial distribution of marine bivalves along the Indian coast

Tropical coastal areas are amongst the most diverse ecosystems in the world. However, there are quite a few coasts that have rarely been studied for their macro-benthic diversity. The Indian coastline presents one such gap area. Two sub-parallel coastlines of India have a wide latitudinal span (8–23°N) and strikingly different physiographic environments. While the east coast receives a high siliciclastic input from large river systems flowing to the Bay of Bengal with fluctuating salinity, the west coast has a large shelf area and high productivity of the Arabian Sea. Such difference enables us to evaluate the effect of regional environmental parameters on marine molluscan diversity and distribution in an intra-tropical setting. Because of the wide latitudinal range, it is also possible to assess if spatial difference in species richness in such a regional scale follows the large-scale biodiversity pattern such as Latitudinal Biodiversity Gradient (LBG) despite inherent environmental variation. We used species distribution of marine bivalves, compiled using bioSearch and the Ocean Productivity database, to address this question. Our results show that intra-tropical species richness of marine bivalves is guided primarily by regional environmental parameters. Even with identical latitudinal extent, higher nutrient availability and larger shelf area, the west coast has significantly lower richness than the east coast; among environmental variables, productivity, salinity and coastline length emerged as significant predictors of species diversity. Moreover, a positive influence of a South Asian biodiversity hotspot on east coast fauna and a negative impact of the oxygen-depleted condition of Arabian Sea on west coast fauna, may have a significant contribution in developing such coastal variation in species richness. The latitudinal variation in species richness did not follow LBG. In contrast to the coast-specific diversity difference, species composition is not found to be dictated by coastal affiliation. The composition corresponds primarily to physiographic conditions. We identified three distinct eco-regions (north-western, southern, north-eastern) with characteristic species composition corresponding to unique physiography and productivity mechanism. The NW region has low siliciclastic input and high productivity associated with upwelling during winter cooling. The NE region has a distinctly high riverine input and salinity fluctuation. The southern region, in contrast, has well developed reefal system with moderate variation in salinity. Such correspondence underscores the importance of the regional environment in dictating the species diversity and distribution in the shallow marine realm.

Sea state in the Baltic Sea from space-borne high-resolution synthetic aperture radar imagery

ABSTRACTIn this work, remote sensing synthetic aperture radar (SAR) data from X-band TerraSAR-X and TanDEM-X (TS-X and TD-X) satellites have been used to adopt the algorithms for estimating sea state parameters in the specific condition of the Baltic Sea with archipelago islands and where short steep sea state dominates. Since the moving targets can be defocused and shifted in SAR images, sea state consisting of short windsea waves with strong local orbital velocities and wave breaking needs additional effort for accurate estimation of the total significant wave height that consists of swell and windsea parts. The XWAVE_C algorithm, developed for the North Sea, where the long swell waves coming from the Atlantic Ocean are present during storms, was further enhanced for the short steep windsea which dominates under ordinary storm conditions in the Baltics. For the empirical XWAVE_C model function, based on the spectral analysis of subscenes as well as on local wind information, an additional term was incorporated for assessment the minimal windsea significant wave height by applying JONSWAP wave spectra. A term to compensate spectral distortions triggered by windsea waves moving in SAR flight direction has also been introduced. In total, 95 TS-X/TD-X StripMap scenes between 2012 and 2017 were acquired in Eastern Baltic Sea, processed and analysed. The wave height results from SAR images were compared with collocated in situ data from 11 available buoys. The analysed data include both high and low windsea conditions. The comparison of SAR-derived wave heights with measured wave heights shows high agreement with a correlation coefficient r of 0.88. The wind speed, estimated from SAR images, was compared to measurements from 14 collocated in situ stations, yielding a high agreement with an r value of 0.90. This article is focused on the algorithm developments; however, it is also the first study of sea state retrieval in the Baltic Sea using high-resolution satellite-based techniques. The results show the local variability in the wave fields connected to atmospheric features. The observed local wave height can increase by 1–2 m in kilometre-size cells that are accompanied by wind gusts. The developed algorithms are installed in the German Aerospace Center’s (DLR) ground station Neustrelitz and can also be used in near-real-time.

Impact of Desiccation of Aral Sea on the Regional Climate of Central Asia Using WRF Model

This study explores the impacts of the desiccation of the Aral Sea and large-scale climate change on the regional climate of Central Asia in the post-1960 era. A series of climate downscaling experiments for the 1960’s and 2000’s decades were performed using the Weather Research and Forecast model at 12-km horizontal resolution. To quantify the impacts of the changing surface boundary condition, a set of simulations with an identical lateral boundary condition but different extents of the Aral Sea were performed. It was found that the desiccation of the Aral Sea leads to more snow (and less rain) as desiccated winter surface is relatively much colder than water surface. In summer, desiccation led to substantial warming over the Aral Sea. These impacts were largely confined to within the area covered by the former Aral Sea and its immediate vicinity, although desiccation of the Sea also led to minor cooling over the greater Central Asia in winter. A contrasting set of simulations with an identical surface boundary condition but different lateral boundary conditions produced more identifiable changes in regional climate over the greater Central Asia which was characterized by a warming trend in both winter and summer. Simulations also showed that while the desiccation of the Aral Sea has significant impacts on the local climate over the Sea, the climate over the greater Central Asia on inter-decadal time scale was more strongly influenced by the continental or global-scale climate change on that time scale.

Simulation of offshore aquaculture system for macro algae (seaweed) oceanic farming

ABSTRACTLarge-scale cultivation of seaweed has become one of the most important aquaculture activities in Malaysia which may help increase farmers’ incomes as well as seaweed itself can be processed into many beneficial end products. The present location of seaweed farming selected by farmers is situated close proximity to the coastline which is between 100 and 200 m from the seashore. The unfavourable condition of sea during rough sea with high wave and high speed of current is always a problem to the farmers since this environmental condition destroys their seaweed planting lines. To avoid the above problem, especially in monsoon prone area, a thorough analysis needs to be done in order to prevent environmental load from destroying seaweed platform on its mooring line when subjected to greater stress. The main objective of this study is to perform a simulation study which will allow analysis of the best mooring system for multi-body floating seaweed farm, together with understanding of the reliability and effectiveness of the system. This paper presents the design of seaweed platform model with mooring assessment in order to obtain a comprehensive and reliable seaweed mooring platform with the aid of mooring simulation software and model tests.

Calcareous nannoplankton in the Upper Jurassic marine deposits of the Bohemian Massif: new data concerning the Boreal - Tethyan communication corridor

Calcareous nannoplankton assemblages from the Jurassic relict deposits in the northern part of the Bohemian Massif are described here for the first time. They are generally of low diversity and dominated by watznaueriaceans. Some of them are diagenetically affected, probably due to dolomitisation. Calcareous nannoplankton enables the stratigraphical range of the Northern Bohemia Jurassic succession to be extended to the Tithonian by reference to the stratigraphical range of Jurassic platform sequences in Central Poland and the eastern part of the Bohemian Massif. The Oxfordian–Kimmeridgian nannofossil assemblages indicate a generally oligotrophic condition of the restricted sea with episodic fluvial input containing terrestrial nutrients. The character of the upper part of the water column was generally uniform and did not reflect variability at the sea-floor expressed by lithofacies diversity. The palaeoenvironment interpreted for the famous former palaeontological locality “Sternberk Quarry” was characterized by a higher nutrient content and more stable environment. The Tithonian nannofossil assemblages contain warm-water Tethyan taxa which suggest south-north migration of nannoplankton due to warming during the Jurassic–Cretaceous boundary interval.

Factors Analysis to Determine the Policy from Four Countries around South China Sea

Since 2012, four countries around South China Sea have emphasized each own policy towards South China Sea. Among them, Vietnam and Philippines have enhanced the policy to resist China, while Malaysia and Brunei have insisted on the established policy to defend their illegal interests. It is argued that those changes are resulted in great shifts about primary factors to affect sea policies from four countries. Those shifts are as followed: measures enhanced by Vietnam and Philippines to struggle for interests of South China Sea; China’s un-sustaining policy altered to be more positive; America’s turning to support Vietnam and Philippines; ASEAN’s balance and outside power’s active intervention. Therefore, those factors steady or not will influence the condition of South China Sea in the future, and the tendency to withstand China will last a long time.

Влияние пыли перегружаемых в портах опасных навалочных грузов на санитарно-экологическое состояния почв припортовых городов причерноморья = Influence of dust transferred into ports of dangerous cargos for bulk sanitary-ecological condition of soils port urban Black Sea

Влияние пыли перегружаемых в портах опасных навалочных грузов на санитарно-экологическое состояния почв припортовых городов причерноморья = Influence of dust transferred into ports of dangerous cargos for bulk sanitary-ecological condition of soils port urban Black Sea

Propagation mechanisms of incident tsunami wave in Jiangsu coastal area, caused by eastern Japan earthquake on March 11, 2011

At 13:46 on March 11, 2011 (Beijing time), an earthquake of Mw=9.0 occurred in Japan. By comparing the tsunami data from Guanhekou marine station with other tsunami wave observation gathered from southeast coastal area of China, it was evident that, only in Guanhekou, the position of the maximum wave height appeared in the middle part rather than in the front of the tsunami wave train. A numerical model of tsunami propagation based on 2-D nonlinear shallow water equations was built to study the impact range and main causes of the special tsunami waveform discovered in Jiangsu coastal area. The results showed that nearly three-quarters of the Jiangsu coastal area, mainly comprised the part north of the radial sand ridges, reached its maximum tsunami wave height in the middle part of the wave train. The main cause of the special waveform was the special underwater topography condition of the Yellow Sea and the East China Sea area, which influenced the tsunami propagation and waveform significantly. Although land boundary reflection brought an effect on the position of the maximum wave height to a certain extent, as the limits of the incident waveform and distances between the observation points and shore, it was not the dominant influence factor of the special waveform. Coriolis force’s impact on the tsunami waves was so weak that it was not the main cause for the special phenomenon in Jiangsu coastal area. The study reminds us that the most destructive wave might not appear in the first one in tsunami wave train.

Recent climate variation in the Bering and Chukchi Seas and its linkages to large-scale circulation in the Pacific

The thermal state of the Bering Sea exhibits interdecadal variations, with distinct changes occurred in 1997–1998. After the unusual thermal condition of the Bering Sea in 1997–1998, we found that the recent climate variability (1999–2010) in the Bering Sea is closely related to Pacific basin-scale atmospheric and oceanic circulation patterns. Specifically, warming in the Bering and Chukchi Seas in this period involves sea ice reduction and stronger oceanic heat flux to the atmosphere in winter. The atmospheric response to the recent warming in the Bering and Chukchi Seas resembles the North Pacific Oscillation (NPO) pattern. Further analysis reveals that the recent climate variability in the Bering and Chukchi Seas has strong covariability with large-scale climate modes in the Pacific, that is, the North Pacific Gyre Oscillation and the central Pacific El Niño. In this study, physical connections among the recent climate variations in the Bering and Chukchi Seas, the NPO pattern and the Pacific large-scale climate patterns are investigated via cyclostationary empirical orthogonal function analysis. An additional model experiment using the National Center for Atmospheric Research Community Atmospheric Model, version 3, is conducted to support the robustness of the results.

Experimental Grow-Out of the Omani AbaloneHaliotis mariaeWood, 1828, in Land-Based Tanks in Mirbat, Oman

Hatched larvae, juveniles, and adults of the Omani abalone Haliotis mariae were cultivated in land-based tanks with filtered running seawater during 3 experiments: (1) from January 2001 to December 2005, (2) from January 2006 to November 2009, and (3) from January 2009 to December 2011. Larvae and early juveniles were fed daily with diatoms, whereas late juveniles and adults were fed with artificial food and the green algae Ulva fasciata. Shell length and total wet weight from 40–80 randomly selected specimens in various experiments were measured monthly, and sex and gonad maturity stage were defined visually. The water parameters in tanks reflected the ambient condition of the Arabian Sea. The growth pattern of the abalone was very similar in the 3 experimental trials. Larvae and early juveniles have very fast growth rates, reaching an average 53–56 mm and 19–25 g after 1 y. Better results were obtained in the second and third experiments, when at the end of 2 y of rearing, abalone mean length was 67–72 mm and the weight was 46–54 g. At the age 3 y, abalone attained a mean length of 83–85 mm and a weight of 89–93 g. After 6 y, the abalone from the first experiment (2001 to 2005) showed, on average, 88.5 mm and 110.9 g. The length increments were the highest during the first year of the culture, whereas weight increments reached maximum values during the third (second and third trials) and fourth year (first trial) of rearing. After 4 y, abalone growth increments in weight decreased significantly. Males generally but not always have larger increments in length and weight when compared with females. During cultivation, a decrease in abalone weight was sometimes observed that, in most cases, coincided with decrease in water temperature during the southwest monsoon period (June to September). Some abalone sexually matured in tanks after 1 y, and mature males and females occurred almost year-round, with peaks in April to May and November to December. The length at first maturity was found to be 65.2 mm for males and 67.1 mm for females. Growth parameters for a von Bertalanffy function were calculated using data from different experiments. The growth rate coefficient in the first experiment was lower (K = 0.65), but in third experiment it appeared higher (K = 0.80) than in natural conditions from data other authors calculated based on length-frequency distribution analysis, which indicates faster growth rates of abalone in tanks when compared with those in the wild. Results of the trials showed that it is feasible to produce Omani abalone in land-based farms from eggs to commercial size during a 3 4-y cycle.

Public preferences regarding use and condition of the Baltic Sea—An international comparison informing marine policy

Marine environments and the ecosystem services they provide are threatened throughout the world. Using an extensive data set obtained from a coordinated survey across all nine littoral countries, this study examines the recreational use of and public perceptions towards the Baltic Sea, providing support for marine policies, including the European Union Marine Strategy Framework Directive. The findings indicate that the Baltic Sea is an important recreation area for residents of the littoral states, as the majority of people spend leisure time there. Swedes, Danes and Finns use the sea the most, and the most common activities are beach recreation and swimming. People are concerned over the state of the Baltic Sea, especially in Finland, Russia and Sweden. Poles, Danes and Finns have the most positive attitude towards contributing financially to improving the state of the Baltic Sea. Additional coordinated research efforts across all nine littoral countries are needed to quantify the monetary benefits of improving the state of the sea. However, even the present results provide evidence on the cultural importance of the Baltic Sea, suggesting that policy makers need to take stronger action to sustain the provision of recreational ecosystem services and safeguarding the well-being of marine ecosystems to the current and future generations.

Assessment of pesticides and polychlorinated biphenyls (PCBs) in sediments of the Egyptian Mediterranean Coast

In an attempt to evaluate the toxicological condition of the Egyptian Mediterranean Sea from El-Sallum to El-Arish, 10 surficial sediment samples were collected from different locations covering the region that receives the majority of the industrial, agricultural and urban effluents (land-based activities), and thus is expected to be contaminated with different degrees of pollution. Sediment samples were analyzed for PCBs (PCB 18, 28, 44, 52, 101, 118, 138, 153, 180 and 194), and organochlorine pesticides (α-HCH, β-HCH, γ-HCH, δ-HCH, heptachlor, methoxychlor, heptachlor-epoxide, aldrin, dieldrin, endrin, endrin aldehyde, endrin ketone, γ-chlordane, α-endosulfane, β-endosulfane, p,p′-DDE, p,p′-DDD, p,p′-DDT). The investigated sediments were dominated by the sand fraction, except Rosetta station. The concentration of organic pollutants in sediments followed the order: Total cyclodienes>PCBs>DDTs>HCHs. Sediments were dominated by the metabolites of DDT (DDD and DDE) indicating that the detected DDTs in the bay sediments are not recently introduced into the bay. At the same time, DDE concentrations were higher than DDD in all the sediment samples (except El-Sallum and Sidi-Kreer) indicating oxic conditions. The risk assessment for organic pollutants were studied, indicating a greater possibility of the occurrence of toxic adverse ecological effects with respect to all investigated organic pollutants and frequent toxic effect is expected for lindane and p,p′-DDT.

Eutrophication, risk management and sustainability. The perceptions of different stakeholders in the northern Baltic Sea

The environmental condition of the Baltic Sea is not only of concern for natural scientists. The awareness of the deteriorating state of the ecosystem has become an issue of interdisciplinary interest, and the amount of organizations with the marine environment and ecosystem health on the agenda is large. To present holistic and sustainable solutions and results of the actions taken, an active cooperation between all stakeholder groups and levels are needed. How different stakeholders in the northern Baltic Sea perceive the structures and assessments of the eutrophication were analyzed by semi-structured interviews with 17 stakeholders representing authorities, scientists, NGOs and national interest organizations. The focus was the view of the governance structures, risk assessment, management and communication. There was an overall consensus that eutrophication is a serious problem. Still variations in the opinions both within and between the stakeholder groups were seen. The scientists were most divergent from the rest.