A MSFD complementary approach for the assessment of pressures, knowledge and data gaps in Southern European Seas : the PERSEUS experience

PERSEUS project aims to identify the most relevant pressures exerted on the ecosystems of the Southern European Seas (SES), highlighting knowledge and data gaps that endanger the achievement of SES Good Environmental Status (GES) as mandated by the Marine Strategy Framework Directive (MSFD). A complementary approach has been adopted, by a meta-analysis of existing literature on pressure/impact/knowledge gaps summarized in tables related to the MSFD descriptors, discriminating open waters from coastal areas. A comparative assessment of the Initial Assessments (IAs) for five SES countries has been also independently performed. The comparison between meta-analysis results and IAs shows similarities for coastal areas only. Major knowledge gaps have been detected for the biodiversity, marine food web, marine litter and underwater noise descriptors. The meta-analysis also allowed the identification of additional research themes targeting research topics that are requested to the achievement of GES. 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license.peer-reviewe

Role of Saharan Dust on Phytoplankton Dynamics in the Northeastern Mediterranean

Effects of atmospheric deposition and other environmental factors on phytoplankton dynamics were evaluated from an open (having offshore characteristics) and a coastal station in the northeastern Mediterranean between December 2000 and December 2001. Data on phytoplankton, chlorophyll a, nutrients, temperature and salinity were obtained at bi-weekly or more intense intervals during 1 yr, whilst transport of Saharan dust towards the sampling region was monitored daily by SeaWiFS (sea-viewing wide field-of-view sensor) images. Diatoms were the group of highest average biomass during the entire investigation period. Although coccolithophores (mainly Emiliania huxleyi) numerically dominated at the open station during the study period, their maximum abundance was as low as 50 × 103 cells. The intensity of dust transport was observed to be highest in spring. Less intense transports were observed in summer and autumn. Several intense episodic dry and wet dust deposition events during the spring season observed by SeaWiFS images caused little or no increase in phytoplankton abundance and biomass in the following days and weeks. Nevertheless, it appears that less intense dust transport events increased phytoplankton abundance and biomass in August, September and October 2001, when water column stratification was at its peak. However, these increases were much weaker than the major winter-early spring bloom (in February and March), which was caused by upwelling, mixing the water column. We suggest that the impact of atmospheric nutrient input on phytoplankton in the Mediterranean is rather low on a yearly basis.JRC.G.3-Agricultur

Effect of Nutrients on Culture Dynamics of Marine Phytoplankton

The effects of nitrate, ammonium and phosphate on the abundance, chlorophyll a content (chl a), in vivo fl uorescence, particulate organic carbon, nitrogen, phosphorus and cell morphology of the diatom Skeletonema costatum, the dinofl agellate Prorocentrum micans and the coccolithophore Emiliania huxleyi were investigated in the laboratory. The carbon:chlorophyll a ratio (as weight), a parameter often used in productivity estimates, differed substantially among the three species as well as at different nutrient concentrations at the end of the exponential growth phase. The cell chl a content was higher in the earlier phases of growth in all three species in agreement with previous investigations. Average chl a content per cell during the experiments was higher in P. micans (8 pg) than in S. costatum (0.4 pg) and E. huxleyi (0.2 pg). However, chl a content per unit volume was higher in E. huxleyi (~15 fg μm–3) than in S. costatum (~7 fg μm–3) and P. micans (~1 fg μm–3). Prorocentrum micans cultures reached the highest total biovolume (74 mm3 L–1 and was 3 and 5 times higher than S. costatum and E. huxleyi cultures, respectively) under high nutrient concentrations. Nevertheless, total chl a concentration of S. costatum culture was almost twice higher (122 μg L–1) than that of the other two species at the end of the exponential growth phase. Phosphate consumption by S. costatum occurred at higher rates compared to the other two species during the experimental period, probably showing that this nutrient was more favourable for this species. Our fi ndings from these laboratory experiments emphasize that chl a values in the natural habitat may not accurately indicate actual phytoplankton biomass.JRC.G.3-Agricultur

Spatio-temporal distribution of picophytoplankton (Pico-eukaryotes, Synechococcus and Prochlorococcus) abundance in the northeastern mediterranean

© 2020 Parlar Scientific Publications. All rights reserved.Primary productivity mostly relies on marine cyanobacteria in the oligotrophic north-eastern Mediterranean (NEM). However, wide shelf basin is fed by nutrient-rich rivers (namely Goksu, Lamas, Seyhan, Ceyhan, Asi) leading to apparent increase in algal production at coastal regions. In the present study, variation of picophytoplankton (pico-eukaryotes, Synechococcus and Prochlorococcus) abundance of at different trophic levels of NEM were investigated. Sample collection was carried out at 50 different stations including Mersin Bay, Goksu River discharge area and oligotrophic offshore waters during October 2017, February, April and July 2018. Minimum and maximum abundance of picoeukaryotes, Synechococcus and Prochlorococcus were found as 1-lxlO4, 103 - 3.3xl04 and SxlO1 - 7.3xl04 cell/ml, respectively. Eukaryotic picoplankton are observed mainly in Goksu River discharge area and could not compete with marine cyanobacteria in offshore waters. Annual average ofpico-eukaryotes abundance was decreased by 1.4 folds from inshore to offshore; while, annual average of Synechococcus abundance was increased by 1.2 folds. Prochlorococcus abundance did not vary from inshore to offshore but decreased by 4 folds from river discharge area to offshore area. Synechococcus and Prochlorococcus have displayed similar abundance profiles with peak levels near the Deep Chlorophyll Maximum (DCM) in October and July. Results showed that Synechococcus was the most abundant regardless of location or season. Even though Synechococcus abundance was found to be higher than Prochlorococcus abundance, a significant increase in the contribution of Prochlorococcus to the total picophytoplankton was observed in July

Eutrophication of the Izmit Bay, Marmara Sea

The elongated Bay of Izmit is one of the most heavily polluted semienclosed basins in Turkey. From systematic data obtained during field studies between 1984 and 1988, it is clear that two distinct water masses are present throughout the year. The brackish water which originated in the Black Sea forms a 10 to 15 m thick surface layer. Its salinity and temperature vary from 22-24 ppt and 20-24 °C in summer, to 26 ppt and 7 °C, in winter. Marine water, which arrived from the Mediterranean, underlies the permanent pycnocline and has much more stable properties: salinity and temperature ranges are 37.5-38.5 ppt and 14-15 °C, respectively. Since the phytoplankton production is limited to the upper layer, including the halocline, nutrients have low surface concentrations in productive seasons and a higher concentration in winter. There is a sharp concentration increase in the halocline to high, almost constant, value in the lower layer. Phytoplankton biomass, in terms of chlorophyll-a concentration, has been found to be as large as 33 pg/L during spring in the more eutrophic inner part of the bay. In March 1988, the production reached the peak value of 3.3 g C/(m2 day) with the mean annual rate of at least 2 to 4 times larger than in the Marmara and Black Seas. Dissolved oxygen concentration decreases in the halocline and varies seasonall

The Evaluation of Fasting Plasma Homocystein Levels in Type II Diabetic Patients with or Without Peripheric Arterial Disease

During the management of patients with diabetes mellitus, almost all patients are evaluated for coronary heart disease but the lesser percentage of diabetic patients are evaluated for peripheral arterial disease, which causes a delay in the diagnosis. It is well known that high plasma homocystein level is associated with arterial and venouse thrombosis, stroke, myocardial infraction and chronic renal failure. The serum level of homocystein is affected by genetical defects of metabolism (such as enzyme defects), chronical disorders, vitamine and calory insufficiencies, demographic characteristics (age, sex, etc.) and some medications. In our study, the fasting plasma homocystein levels among type II diabetes mellitus patients with or without peripheral arterial disease were investigated. Group I Including 36 patients had type II diabetes mellitus with peripheral arterial disease (26 male and 10 female). Group II including 34 patients had type II diabetes mellitus without peripheral arterial disease (11 male and 19 female). Different biochemical parameters and fasting homocysteine levels were measured in each subjects. We showed that there was a negative mild correlation between creatinine clearance and homocysteine levels; while there were no siginificant correlations between homocysteine and serum cholesterol, triglyceride, LDL and HDL-cholesterol and fibrinogen levels. Finally we didn't find any correlation in the levels of homocysteine between the group of patients with or without peripheral artery disease, but the homocysteine levels of patients with ischemic heart disease were higher than the patients without ischemic heart disease

(Table 4) Mesozooplankton abundance and biomass and relative percentage of key zooplankton groups along the Bulgarian coast, Black Sea

Results of studies during Project of an international expedition onboard R/V Vladimir Parshin in September-October 2005 are presented. Intensive development of Bacillariophyceae and Dynophyceae was recorded in coastal waters of Bulgaria, Turkey, and in the Danube River delta during period of investigations. Increase in algae population was accompanied by rising of chlorophyll a concentration up to 2.0-5.5 µg/l. In the deep water region it did not exceed 0.5 µg/l. Phytoplankton growth rate in the surface water layer varied from 0.1 to 1.0 1/day. This parameter and NO2+NO3 concentration, as well as the silicon concentration were correlative, as was described by the Michaelis-Menten equation. Phytoplankton growth was affected by basic nutrients. Zooplankton grazing varied from 0.10 to 0.69 1/day and average values in different regions varied by 1.5 times. Microalgae size range is one of major factors of grazing regulation. Rate of phytoplankton consumption was decreasing with increasing the largest diatom Pseudosolenia calcar-avis impact on total biomass of nano- and microphytoplankton

Assessing the impact of nutrient loads on eutrophication in the semi-enclosed Izmir Bay combining observations and coupled hydrodynamic-ecosystem modelling

International audienceIntense human activities may strongly affect coastal environments threatening natural, societal and economic resources. In order to propose adequate measures to preserve coastal marine areas, a thorough understanding of their physical and biogeochemical features is required. This study focuses on one such coastal area, Izmir Bay located in the Eastern Mediterranean Sea. Izmir Bay is a highly populated area subject to many human induced stressors such as pollution and eutrophication, that has been suffering high nutrient loads for decades. Despite the construction of the Çiğli waste water treatment plant in 2000-2001 to reduce eutrophication, such pressures continue to occur. To study the current physical and biogeochemical dynamics of Izmir Bay and their spatial and temporal variability, a three-dimensional coupled hydrodynamic-ecosystem model (Delft3D modelling suite’s FLOW and ECO modules) is implemented. Using the model, the effect of excessive inorganic nutrient loading on the marine ecosystem as the main cause of this eutrophication is explored in an effort to advise on mitigation efforts for the Bay focusing on eliminating eutrophication. Results of different model scenarios show that the Inner and Middle Bay are nitrogen-limited while the Outer Bay is phosphorus-limited. Inner regions are more sensitive to variations in inorganic nitrogen input due to the low (<16) N/P ratio of nutrients in seawater. An increase in inorganic nitrogen triggers eutrophication events with primary production as an immediate response. Conversely, the Outer Bay ecosystem with N/P ratios above 16 is more sensitive to phosphate inputs, of which an increase causes a considerable enhancement in algal production. This study shows the vulnerability of Izmir Bay to anthropogenic nutrient input and model simulations indicate that management plans should consider reducing DIN discharges both in the inner-middle zones of Izmir Bay as well as inputs from the Gediz River. Additionally, phosphate inputs should be reduced to avoid an overall increase of algal production in the Outer Bay, the larger part of Izmir Bay