Taxonomic notes on Protoperidinium (Peridiniales, Dinophyceae) species in the Thermaikos Bay (North Aegean Sea, Greece)

The thecal morphology and plate pattern of fourteen species of the genus Protoperidinium, found in the inner Thermaikos Bay (North Aegean Sea, Eastern Mediterranean) during the period 1989-1992, are described and discussed. These species are: P. depressum, P. oceanicum, P. oblongum, P. claudicans, P. punctulatum, P. conicum var. concavum ?, P. cf. obtusum, P. sp., P. brochi, P. divergens, P. curtipes, P. oviforme, P. pallidum and P. diabolus. Among the fourteen species, P. cf. obtusum and P. sp. are the most interesting from a taxonomic point of view. The morphology of the theca of each species combines features attributed in the current literature to two different species, P. obtusum and P. leonis. These features concern primarily the shape of the 1' plate and the morphology of the hypotheca. As a consequence of my findings, I believe that the morphology of the 1’ plate and the sculpture of the epitheca may be too variable to be used to distinguish between P. obtusum and P. leonis. We also believe that P. obtusum, P. leonis as well as P. striatum require further clarification of their diagnostic characters. Taxa of similar morphology to P. sp. have been recorded in the literature and they may represent a new Protoperidinium taxon

Ecosystem processes: litter breakdown patterns in Mediterranean and Black Sea transitional waters

1 - Leaf litter decomposition rates, in aquatic ecosystems, are known to be related to many different abiotic and biotic factors. 2 - Here, we focus on the influence of abiotic factors, searching for patterns of reed litter decay rates on gradient of physiographic, hydrological and physico-chemical components of transitional water ecosystems. 3 - Field experiments were carried out in 16 water ecosystems in the Eastern Mediterranean and Black Sea in spring 2005. 4 - Significant differences of leaf litter decomposition were observed among ecosystems along univariate gradient of tidal range, index of sinuosity, water temperature and salinity. At least 71% of variance in the litter breakdown rate was explained by the considered abiotic factors. 5 - It is concluded that, at the macro-ecological scale of study, some key abiotic factors, such as tidal range and salinity, are suggested to play a major role as drivers of plant detritus decomposition processes. 6 - The relevance of the described abiotic drivers as descriptor of the most commonly used classification schemes for transitional water ecosystems (i.e., Confinement and Venice System classifications), is a further support to their role as environmental forcing factors

A risk-based approach to cumulative effect assessments for marine management

Marine ecosystems are increasingly threatened by the cumulative effects of multiple human pressures. Cumulative effect assessments (CEAs) are needed to inform environmental policy and guide ecosystem-based management. Yet, CEAs are inherently complex and seldom linked to real-world management processes. Therefore we propose entrenching CEAs in a risk management process, comprising the steps of risk identification, risk analysis and risk evaluation. We provide guidance to operationalize a risk-based approach to CEAs by describing for each step guiding principles and desired outcomes, scientific challenges and practical solutions. We reviewed the treatment of uncertainty in CEAs and the contribution of different tools and data sources to the implementation of a risk based approach to CEAs. We show that a risk-based approach to CEAs decreases complexity, allows for the transparent treatment of uncertainty and streamlines the uptake of scientific outcomes into the science-policy interface. Hence, its adoption can help bridging the gap between science and decision-making in ecosystem-based management

W.G. Sebald and the work of narrative melancholia

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Spatial and seasonal variability of the macrobenthic fauna in Mediterranean solar saltworks ecosystems

1. Solar saltworks are man-made systems for the production of salt and are characterized by high habitat heterogeneity owing to the existence of a strong salinity/confinement gradient. Although solar saltworks are considered to be artificial systems, they are also coastal aquatic ecosystems sharing common characteristics with natural transitional waters ecosystems, which are of special interest to the Water Framework Directive (2000/60/EC). 2. Spatial and seasonal distribution of macrobenthic invertebrates in relation to the abiotic environment of two Mediterranean solar saltworks ecosystems were assessed in this study. The spatial distribution investigated in this study ranged from the regional scale (Kalloni Saltworks, NE Aegean and Margherita di Savoia Saltworks, S. Adriatic) down to a local scale of 100s of metres in each ecosystem. 3. The macrobenthic community was variable at most spatial and seasonal scales examined in this study: spatial variability at the regional level was greater than seasonal variability within ecosystems and spatial variability among the salinity/confinement gradient levels was greater than within-level variability. 4. The abiotic environment, in both its spatial and seasonal aspects, was found to be crucial in determining the macrobenthic community structure. Biotic factors such as the life cycle of key species, the inter-specific competition as well as dispersion/colonization/extinction processes were also found to play an important role in structuring the macrobenthic fauna both in space and time. 5. A strong similarity of the macroinvertebrate faunal composition and community structure of the lower salinity ponds of solar saltworks with that of natural transitional waters ecosystems was observed. Therefore, solar saltworks ecosystems can be considered as important sites of study for the purposes of the Water Framework Directive

Ecosystem processes: Litter breakdown patterns in mediterranean and black sea transitional waters

Leaf litter decomposition rates, in aquatic ecosystems, are known to be related to many different abiotic and biotic factors. Here, we focus on the influence of abiotic factors, searching for patterns of reed litter decay rates on gradient of physiographic, hydrological and physico-chemical components of transitional water ecosystems. Field experiments were carried out in 16 water ecosystems in the Eastern Mediterranean and Black Sea in spring 2005. Significant differences of leaf litter decomposition were observed among ecosystems along univariate gradient of tidal range, index of sinuosity, water temperature and salinity. At least 71% of variance in the litter breakdown rate was explained by the considered abiotic factors. It is concluded that, at the macro-ecological scale of study, some key abiotic factors, such as tidal range and salinity, are suggested to play a major role as drivers of plant detritus decomposition processes. The relevance of the described abiotic drivers as descriptor of the most commonly used classification schemes for transitional water ecosystems (i.e., Confinement and Venice System classifications), is a further support to their role as environmental forcing factors. © 2007 University of Salento

Environmental factors affecting Phragmites australis litter decomposition in Mediterranean and Black Sea transitional waters

1. Leaf litter decomposition rates in aquatic ecosystems are known to be related to many abiotic and biotic factors. 2. Field experiments were carried out during spring 2005 in 16 ecosystems, each with four sampling sites, using the litter bag technique to investigate the influence of abiotic factors on patterns of reed litter breakdown in different physiographic, hydrological and physico-chemical gradients occurring in transitional water ecosystems in the Eastern Mediterranean and Black Sea. 3. Significant differences in leaf litter decomposition were observed among the studied ecosystems along univariate gradients of tidal range, water temperature, salinity and sinuosity index. 4. Overall, 71% of variance in the litter breakdown rate was explained by the hydrological, physico-chemical and physiographic components. Specifically, tidal range, salinity and sinuosity index are among the key factors in the most commonly used typological schemes for classifying transitional water ecosystems (i.e. Confinement Concept and Venice System), due to their influence on abundance and distribution of benthic macroinvertebrates and other guilds. 5. The patterns observed at the regional scale of the study suggest that certain key abiotic factors are likely to play a major role as drivers of plant detritus decomposition processes, through their influence on the overall metabolism of microorganisms and benthic macroinvertebrates. 6. These observations have implications for the identification of reference conditions for transitional water ecosystems in the studied area, on which all processes of classification and conservation of their ecological status are based. Copyright © 2008 John Wiley & Sons, Ltd

Ecosystem processes: Litter breakdown patterns in mediterranean and black sea transitional waters

Leaf litter decomposition rates, in aquatic ecosystems, are known to be related to many different abiotic and biotic factors. Here, we focus on the influence of abiotic factors, searching for patterns of reed litter decay rates on gradient of physiographic, hydrological and physico-chemical components of transitional water ecosystems. Field experiments were carried out in 16 water ecosystems in the Eastern Mediterranean and Black Sea in spring 2005. Significant differences of leaf litter decomposition were observed among ecosystems along univariate gradient of tidal range, index of sinuosity, water temperature and salinity. At least 71% of variance in the litter breakdown rate was explained by the considered abiotic factors. It is concluded that, at the macro-ecological scale of study, some key abiotic factors, such as tidal range and salinity, are suggested to play a major role as drivers of plant detritus decomposition processes. The relevance of the described abiotic drivers as descriptor of the most commonly used classification schemes for transitional water ecosystems (i.e., Confinement and Venice System classifications), is a further support to their role as environmental forcing factors. © 2007 University of Salento