DIVERSITY AND DISTRIBUTIONS, Issue 4 2004
Trudi N. Wharton
ABSTRACT Essigella californica is a pine aphid native to western North America. In Australia, E. californica is considered an invasive pest that has the potential to cause severe economic loss to the Australian forestry industry. Two CLIMEX models were developed to predict the Australian and global distribution of E. californica under current climate conditions based upon the aphid's known North American distribution. The first model (model I) was fitted using the reasonably contiguous set of location records in North America that constituted the known range of E. californica, and excluded consideration of a single (reliable) location record of the aphid in southern Florida. The second model (model II) was fitted using all known records in North America. Model I indicated that the aphid would be climatically restricted to the temperate, Mediterranean and subtropical climatic regions of Australia. In northern Australia it would be limited by hot, wet conditions, while in more central areas of Australia it is limited by hot, dry conditions. Model II is more consistent with the current Australian distribution of E. californica. The contrast in geographical range and climatic conditions encompassed between the two models appears to represent the difference between the realized niche (model I) and fundamental niche (model II) of E. californica. The difference may represent the strength of biotic factors such as host limitation, competition and parasitism in limiting geographical spread in the native range. This paper provides a risk map for E. californica colonization in Australia and globally. E. californica is likely to remain a feature of the Australian pine plantations, and any feasibility studies into establishing coniferous plantations in lower rainfall areas should consider the likely impact of E. californica. [source]

Review article: Mohammed, the early medieval Mediterranean, and Charlemagne

EARLY MEDIEVAL EUROPE, Issue 3 2002
Paolo Squatriti
Peregrine Horden and Nicholas Purcell. The Corrupting Sea. A Study in Mediterranean History [source]

Climate-driven decrease in erosion in extant Mediterranean badlands

EARTH SURFACE PROCESSES AND LANDFORMS, Issue 11 2010
Michèle L. Clarke
Abstract Badland areas provide some of the highest erosion rates globally. Most studies of erosion have insufficient lengths of record to interrogate the impacts of decadal-scale changes in precipitation on rates of badland erosion in regions such as the Mediterranean, which are known to be sensitive to land degradation and desertification. Erosion measurements, derived from field monitoring using erosion pins, in southern Italy during the period 1974,2004 are used to explore the impacts of changing precipitation patterns on badland erosion. Erosion on badland inter-rill areas is strongly correlated with cumulative rainfall over each monitoring period. Annual precipitation has a substantial dynamic range, but both annual and winter (December, January, February) rainfall amounts in southern Italy show a steady decrease over the period 1970,2000. The persistence of positive values of the winter North Atlantic Oscillation index in the period 1980,2000 is correlated with a reduction in the winter rainfall amounts. Future climate scenarios show a reduction in annual rainfall across the western and central Mediterranean which is likely to result in a further reduction in erosion rates in existing badlands. Copyright © 2010 John Wiley & Sons, Ltd. [source]

Rainfall variability and hydrological and erosive response of an olive tree microcatchment under no-tillage with a spontaneous grass cover in Spain

EARTH SURFACE PROCESSES AND LANDFORMS, Issue 7 2010
E. V. Taguas
Abstract Most studies on runoff and soil loss from olive orchards were performed on plots, despite the fact that measurements that examine a range of erosive processes on different scales are essential to evaluate the suitability of the use and soil management of this type of land. The main environmental limitations of much of the land used for olive orchards in the Mediterranean are the steep slopes and the shallow soil depth , and this was the case in the study area. Soil erosion and runoff over two hydrological years (2005,2006 and 2006,2007) were monitored in an olive orchard microcatchment of 6·1,ha under no-tillage with spontaneous grass in order to evaluate its hydrological and erosive behaviour. Moreover, soil parameters such as organic matter (%OM), bulk density (BD) and hydraulic saturated conductivity (Ks) were also examined in the microcatchment to describe management effects on hydrological balance and on erosive processes. In the study period, the results showed runoff coefficients of 6·0% in the first year and 0·9% in the second. The differences respond to the impact of two or three yearly maximum events which were decisive in the annual balances. On the event scale, although maximum rainfall intensity values had a big influence on peak flows and runoff, its importance on mean sediment concentrations and sediment discharges was difficult to interpret due to the likely control of grass cover on volume runoff and on soil protection. In the case of annual soil erosion, they were measured as 1·0,Mg,ha,1,yr,1 and 0·3,Mg,ha,1,yr,1. Both are lower than the tolerance values evaluated in Andalusia (Spain). These results support the implementation of no-tillage with spontaneous grass cover for sloping land, although the reduced infiltration conditions determined by Ks in the first horizon suggest grass should be allowed to grow not only in spring but also in autumn. In addition, specific measurements to control gullies, which have formed in the terraced area in the catchment, should be included since it is expected that they could be the main sources of sediments. Copyright © 2010 John Wiley & Sons, Ltd. [source]

Textural and compositional controls on modern beach and dune sands, New Zealand

EARTH SURFACE PROCESSES AND LANDFORMS, Issue 3 2007
J. J. Kasper-Zubillaga
Abstract Textural, compositional, physical and geophysical determinations were carried out on 111 beach and dune sand samples from two areas in New Zealand: the Kapiti,Foxton coast sourced by terranes of andesite and greywackes and the Farewell Spit,Wharariki coast sourced by a wide variety of Paleozoic terranes. Our aim is to understand how long-shore drift, beach width and source rock control the sedimentological and petrographic characteristics of beach and dune sands. Furthermore, this study shows the usefulness of specific minerals (quartz, plagioclase with magnetite inclusions, monomineralic opaque grains) to interpret the physical processes (fluvial discharges, long-shore currents, winds) that distribute beach and dune sands in narrow and wide coastal plains. This was done by means of direct (grain size and modal analyses) and indirect (specific gravity, magnetic/non-magnetic separations M/NM, magnetic susceptibility measurements, hysteresis loops) methods. Results are compared with beach sands from Hawaii, Oregon, the Spanish Mediterranean, Elba Island and Southern California. Compositionally, the Kapiti,Foxton sands are similar to first-order immature sands, which retain their fluvial signature. This results from the high discharge of rivers and the narrow beaches that control the composition of the Kapiti,Foxton sands. The abundance of feldspar with magnetite inclusions controls the specific gravity of the Kapiti,Foxton sands due to their low content of opaque minerals and coarse grain size. Magnetic susceptibility of the sands is related mainly to the abundance of feldspars with Fe oxides, volcanic lithics and free-opaque minerals. The Farewell Spit,Wharariki sands are slightly more mature than the Kapiti,Foxton sands. The composition of the Farewell Spit,Wharariki sands does not reflect accurately their provenance due to the prevalence of long-shore drift, waves, little river input and a wide beach. Low abundance of feldspar with magnetite inclusions and free opaque grains produces poor correlations between specific gravity (Sg) and Fe oxide bearing minerals. The small correlation between opaque grains and M/NM may be related to grain size. The magnetic susceptibility of Farewell Spit,Wharariki sands is low due to the low content of grains with magnetite inclusions. Hysteresis and isothermal remnant magnetization (IRM) agree with the magnetic susceptibility values. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Late Quaternary vadose carbonate diagenesis in coastal and desert dune and beach sands: is there a palaeoclimatic signal?

EARTH SURFACE PROCESSES AND LANDFORMS, Issue 12 2004
Sue McLaren
Abstract A study of the variation in cement amounts in aeolianite and sandy beach calcarenites that range in age from Holocene to Last Interglacial is used to assess whether a palaeoclimatic control on vadose diagenesis can be identi,ed. Examples are taken from modern-day arid to subhumid settings and represent a geographical distribution ranging from Libya and Oman, to the Mediterranean, the Caribbean and Mexico. The results indicate that a palaeoclimatic signal can be identi,ed in some deposits. However, in other sediments there is substantial variability in mean cement abundance within deposits as well as between these sand bodies. Moreover, many of the better cemented sediments are located in areas where there is accelerated diagenesis, such as in the sea spray zone, close to the groundwater table or near to a palaeosurface, rather than in climatically wet regions. The inference is that palaeoclimatic interpretations are substantially complicated by other factors that affect diagenetic processes and change. Therefore caution is needed when studying the role of climate in vadose diagenesis in the light of the effects of other intrinsic and extrinsic controls. This paper does not aim to provide a de,nitive comparison of sites from different climatic zones. The approach taken here is: (a) to see if there is an overall palaeoclimatic signal in the samples studied; (b) to use examples to illustrate how explanations/controls other than those relating to climate can account for the variabilities observed; and (c) if there is a climatic effect, to see if it is the main over-riding control on vadose diagenesis. The conclusions drawn from this research highlight that it is possible to misinterpret evidence if the study is approached with preconceived notions of simplistic relationships between diagenesis and climate. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Age-related change in canopy traits shifts conspecific facilitation to interference in a semi-arid shrubland

ECOGRAPHY, Issue 4 2007
Orna Reisman-Berman
Shifts between facilitation and interference and their importance in shaping plant population and community dynamics have received wide recognition. Nevertheless, the causes and spatio-temporal scales of these shifts are poorly understood, yet strongly debated. This study tested the hypothesis that age-related changes in canopy structure shift the effect of a nurse shrub on their protégé from facilitation to interference, using as a model system the interaction between the dwarf shrub Sarcopoterium spinosum and conspecific new recruits, in the shrubland of the transition area between the Mediterranean and the semi-arid climatic zones of Israel. Foliation level (i.e. the percentage of canopy surface area covered with leaves), a measure of shrub canopy structure, increased with age. Shading level was significantly and positively related to foliation level. Densities of new recruits in the shrubland showed a unimodal response to canopy structure and cover: the highest densities were associated with canopies presenting low and medium foliation levels (providing 71 and 82% shade, respectively), while high foliation levels (93% shade) and open spaces among canopies were characterized by very low densities. A related field experiment using shading nets revealed that seedling survival rates followed a similar unimodal pattern, with the highest survival (ca 60%) detected in moderate shade (70%), twice as much as in full sun, and the lowest survival (ca 10%) observed in extreme shade (90%). These results support the study hypothesis on age-dependent interactions. Thus, in a semi-arid shrubland ecosystem, the transition of the "nurse shrub" from "young" to "old" stage can shift facilitation to interference. Hence, the age structure of established shrub populations determines a) the availability of suitable sites for seedling recruitment and b) the balance between facilitation versus interference effects on seedling establishment. [source]

The waning of the Mediterranean 1550,1870: a geohistorical approach

ECONOMIC HISTORY REVIEW, Issue 3 2009
Jack A. Goldstone
No abstract is available for this article. [source]

Patapius spinosus: First record of Leptopodidae (Heteroptera) from Japan

ENTOMOLOGICAL SCIENCE, Issue 4 2004
Kazuo YAMAZAKI
Abstract Patapius spinosus, a remarkable leptopodid bug whose body is covered with spines, was collected for the first time in Japan. This species was found in the supralittoral zone of a sandy beach in Osaka Prefecture, central Japan, in autumn 2002 and in spring 2004. Patapius spinosus is known to be distributed in the Mediterranean and North African regions, and has been introduced into North America and Chile. Its occurrence in Japan could signify either an eastern limit of its native distribution or an exotic origin. [source]

Multiple bacterial symbionts in two species of co-occurring gutless oligochaete worms from Mediterranean sea grass sediments

ENVIRONMENTAL MICROBIOLOGY, Issue 12 2008
Caroline Ruehland
Summary Gutless oligochaete worms are found worldwide in the pore waters of marine sediments and live in symbiosis with chemoautotrophic sulfur-oxidizing bacteria. In the Mediterranean, two species of gutless oligochaete worms, Olavius algarvensis and O. ilvae, co-occur in sediments around sea grass beds. These sediments have extremely low sulfide concentrations (< 1 ,M), raising the question if O. ilvae, as shown previously for O. algarvensis, also harbours sulfate-reducing symbionts that provide its sulfur-oxidizing symbionts with reduced sulfur compounds. In this study, we used fluorescence in situ hybridization (FISH) and comparative sequence analysis of genes for 16S rRNA, sulfur metabolism (aprA and dsrAB), and autotrophic carbon fixation (cbbL) to examine the microbial community of O. ilvae and re-examine the O. algarvensis symbiosis. In addition to the four previously described symbionts of O. algarvensis, in this study a fifth symbiont belonging to the Spirochaetes was found in these hosts. The symbiotic community of O. ilvae was similar to that of O. algarvensis and also included two gammaproteobacterial sulfur oxidizers and two deltaproteobacterial sulfate reducers, but not a spirochete. The phylogenetic and metabolic similarity of the symbiotic communities in these two co-occurring host species that are not closely related to each other indicates that syntrophic sulfur cycling provides a strong selective advantage to these worms in their sulfide-poor environment. [source]

Comparative analysis of genome fragments of Acidobacteria from deep Mediterranean plankton

ENVIRONMENTAL MICROBIOLOGY, Issue 10 2008
Achim Quaiser
Summary Acidobacteria constitute a still poorly studied phylum that is well represented in soils. Recent studies suggest that members of this phylum may be also abundant in deep-sea plankton, but their relative abundance and ecological role in this ecosystem are completely unknown. A recent screening of three metagenomic deep-sea libraries of bathypelagic plankton from the South Atlantic (1000 m depth), the Adriatic (1000 m depth) and the Ionian (3000 m depth) seas in the Mediterranean revealed an unexpected relative proportion of acidobacterial fosmids, which affiliated to the Solibacterales (Group 3), to the Group 11 and, most frequently, to the Group 6 of this diverse phylum. Here, we present the comparative analysis of 11 acidobacterial genome fragments containing the rrn operon from these Mediterranean libraries. A highly conserved syntenic region spanning up to 30 kb and containing up to 25 open reading frames was shared by Group 6 Acidobacteria. Synteny was also partially conserved in distantly related acidobacterial genome fragments derived from a metagenomic soil library, indicating a remarkable conservation of this genomic region within these Acidobacteria. A search for Acidobacteria -specific hits in directly comparable, available fosmid-end sequences from soil and marine metagenomic libraries showed a significant increase of their relative proportion in plankton libraries as a function of increasing depth reaching, at high depth, levels nearly comparable to those of soil. Thus, our results suggest that Acidobacteria are abundant and represent a significant proportion of the microbial community in the deep-sea ecosystem. [source]

Sponge disease: a global threat?

ENVIRONMENTAL MICROBIOLOGY, Issue 6 2007
Nicole S. Webster
Summary Sponges are the most simple and primitive metazoans, yet they have various biological and ecological properties that make them an influential component of coral-reef ecosystems. Marine sponges provide refuge for many small invertebrates and are critical to benthic-pelagic coupling across a wide range of habitats. Reports of sponge disease have increased dramatically in recent years with sponge populations decimated throughout the Mediterranean and Caribbean. Reports also suggest an increased prevalence of sponge disease in Papua New Guinea, the Great Barrier Reef and in the reefs of Cozumel, Mexico. These epidemics can have severe impacts on the survival of sponge populations, the ecology of the reef and the fate of associated marine invertebrates. Despite the ecological and commercial importance of sponges, the understanding of sponge disease is limited. There has generally been a failure to isolate and identify the causative agents of sponge disease, with only one case confirming Koch's postulates and identifying a novel Alphaproteobacteria strain as the primary pathogen. Other potential disease agents include fungi, viruses, cyanobacteria and bacterial strains within the Bacillus and Pseudomonas genera. There is some evidence for correlations between sponge disease and environmental factors such as climate change and urban/agricultural runoff. This review summarizes the occurrence of sponge disease, describes the syndromes identified thus far, explores potential linkages with environmental change and proposes a strategy for future research towards better management of sponge disease outbreaks. [source]

Sponges as biomonitors of heavy metals in spatial and temporal surveys in northwestern Mediterranean: Multispecies comparison,

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2007
Emma Cebrian
Abstract Contamination by heavy metals has increased drastically in the coastal Mediterranean during the last 20 years. A comparative study on metal bioaccumulation by four widespread sponge species (Crambe crambe, Chondrosia reniformis, Phorbas tenacior, and Dysidea avara) has been performed to select the most suitable species for metal monitoring. Copper bioaccumulation fits an accumulation strategy while Pb concentration seems to be regulated in most sponges. Crambe crambe was the only studied species that bioaccumulated Pb and Cu as a function of the available metal, proving its suitability for monitoring purposes. Then, we examined its effectiveness as a bioindicator at large spatial and temporal scales, comparing metal accumulation in this species and in sediments. Crambe crambe provided accurate information on the background levels of metals in the area at both spatial and temporal scales, and furthermore it reflected seasonal fluctuations of the bioavailable metals, which would be impossible to assess by means of a sediment survey. [source]

Evaluation of the genetic basis of phenotypic heterogeneity in north Indian patients with Thalassemia major

EUROPEAN JOURNAL OF HAEMATOLOGY, Issue 6 2010
Nidhi Sharma
Abstract Objectives: To assess the molecular basis of phenotypic heterogeneity in north Indian patients with thalassemia major (TM). Methods: To determine the clinical severity, 130 patients of TM were studied for the age of first presentation and frequency of blood transfusion. The type of beta mutations, Xmn,1G, polymorphism and G6PD Mediterranean mutation was characterized. Analysis of the phenotypic presentation and the genotype was performed. Results: Majority (83.8%) presented before 1 year of age (mean 8.8 months). The caste distribution showed 41.6% were Aroras and 32.3% were migrants from Pakistan. IVS1-5(G,C) was commonest (32.7%) and the common five Indian mutations comprised of 88.4% of alleles. The mean age of presentation with IVS1-5(G,C), Fr 8/9, (+G) 619-bp del and IVS1-1(G,T) homozygosity was 4.3, 6, 3.4 and 9.1 months respectively. Xmn,1G, status showed ,/, in 66.9%, +/, in 26.1% and +/+ in 6.9% patients. Xmn,1G,,/, presented before 1 year of age. The mean age of presentation with +/+ was 18.3 months. Six hemizygous boys and one heterozygous girl with G6PD Mediterranean were found (prevalence 5.3%). Eight patients could be reclassified as thalassemia intermedia on follow up. Conclusions: This study showed that majority of TM in north India present before 1 year of age and homozygous 619-bp deletion presents the earliest. The presence of Xmn-1G, polymorphism delays the presentation, is associated with the IVS 1-1 (G,T) and shows variable improvement with hydroxyurea therapy. Based on the results of genotyping, reevaluation of patients can improve the outcome in a few patients. [source]

Changes in organic matter, nitrogen, phosphorus and cations in soil as a result of fire and water erosion in a Mediterranean landscape

EUROPEAN JOURNAL OF SOIL SCIENCE, Issue 2 2000
E. Gimeno-García
Summary Fire affects large parts of the dry Mediterranean shrubland, resulting in erosion and losses of plant nutrients. We have attempted to measure these effects experimentally on a calcareous hillside representative of such shrubland. Experimental fires were made on plots (4 m × 20 m) in which the fuel was controlled to obtain two different fire intensities giving means of soil surface temperature of 439°C and 232°C with temperatures exceeding 100°C lasting for 36 min and 17 min. The immediate and subsequent changes induced by fire on the soil's organic matter content and other soil chemical properties were evaluated, together with the impact of water erosion. Seven erosive rain events, which occurred after the experimental fires (from August 1995 to December 1996), were selected, and on them runoff and sediment produced from each plot were measured. The sediments collected were weighed and analysed. Taking into account the variations induced by fire on the soil properties and their losses by water erosion, estimates of the net inputs and outputs of the soil system were made. Results show that the greatest losses of both soil and nutrients took place in the 4 months immediately after the fire. Plots affected by the most intense fire showed greater losses of soil (4077 kg ha,1) than those with moderate fire intensity (3280 kg ha,1). The unburned plots produced the least sediment (72.8 kg ha,1). Organic matter and nutrient losses by water erosion were related to the degree of fire intensity. However, the largest losses of N-NH4+ and N-NO3, by water erosion corresponded to the moderate fire (8.1 and 7.5 mg N m,2, respectively). [source]

TIME TO THE MOST RECENT COMMON ANCESTOR AND DIVERGENCE TIMES OF POPULATIONS OF COMMON CHAFFINCHES (FRINGILLA COELEBS) IN EUROPE AND NORTH AFRICA: INSIGHTS INTO PLEISTOCENE REFUGIA AND CURRENT LEVELS OF MIGRATION

EVOLUTION, Issue 1 2002
Cortland K. Griswold
Abstract We analyzed sequences from a 275-bp hypervariable region in the 5, end of the mitochondrial DNA control region in 190 common chaffinches (Fringilla coelebs) from 19 populations in Europe and North Africa, including new samples from Greece and Morocco. Coalescent techniques were applied to estimate the time to the most recent common ancestor (TMRCA) and divergence times of these populations. The first objective of this study was to infer the locations of refugia where chaffinches survived the last glacial episode, and this was achieved by estimating the TMRCA of populations in regions surrounding the Mediterranean that were unglaciated in the late Pleistocene. Although extant populations in Iberia, Corsica, Greece, and North Africa harbor haplotypes that are basal in a phylogenetic tree, this information alone cannot be used to infer that these localities served as refugia, because it is impossible to infer the ages of populations and their divergence times without also considering the population genetic processes of mutation, migration, and drift. Provided we assume the TMRCAs of populations are a reasonable estimate of a population's age, coalescent-based methods place resident populations in Iberia, Corsica, Greece, and North Africa during the time of the last glacial maximum, suggesting these regions served as refugia for the common chaffinch. The second objective was to determine when populations began diverging from each other and to use this as a baseline to estimate current levels of gene flow. Divergence time estimates suggest that European populations began diverging about 60,000 years before present. The relatively recent divergence of populations in North Africa, Italy, and Iberia may explain why classic migration estimates based on equilibrium assumptions are high for these populations. We compare these estimates with nonequilibrium-based estimates and show that the nonequilibrium estimates are consistently lower than the equilibrium estimates. [source]

ISOLATION BY DISTANCE IN EQUILIBRIUM AND NONEQUILIBRIUM POPULATIONS OF FOUR TALITRID SPECIES IN THE MEDITERRANEAN SEA

EVOLUTION, Issue 5 2000
Elvira De Matthaeis
Abstract Allozymic variation at 21,23 loci was studied in 28 populations of Talitrus saltator, 23 populations of Orchestia montagui, 13 populations of O. stephenseni, and five populations of Platorchestia platensis from the Mediterranean Basin. Different levels of gene flow (Nm,) were detected within each species at the scale of the whole Mediterranean: O. montagui and P. platensis had low population structure, with levels of Nm, 1, whereas the T. saltator and O. stephenseni populations have values of Nm, < 1. The relationship between Nm, and geographic distance was analyzed to test for the presence of an isolation by distance pattern in the spatial genetic variation within each species. A model of isolation by distance is useful to describe the pattern of genetic structuring of study species at the scale of the whole Mediterranean: geographic distance explained from 28% to 70% of the variation in gene flow. In the Aegean area all species showed an island model of genetic structuring regardless of the levels of gene flow. [source]

Voracious invader or benign feline?

FISH AND FISHERIES, Issue 3 2009
A review of the environmental biology of European catfish Silurus glanis in its native, introduced ranges
Abstract A popular species for food and sport, the European catfish (Silurus glanis) is well-studied in its native range, but little studied in its introduced range. Silurus glanis is the largest-bodied freshwater fish of Europe and is historically known to take a wide range of food items including human remains. As a result of its piscivorous diet, S. glanis is assumed to be an invasive fish species presenting a risk to native species and ecosystems. To assess the potential risks of S. glanis introductions, published and ,grey' literature on the species' environmental biology (but not aquaculture) was extensively reviewed. Silurus glanis appears well adapted to, and sufficiently robust for, translocation and introduction outside its native range. A nest-guarding species, S. glanis is long-lived, rather sedentary and produces relatively fewer eggs per body mass than many fish species. It appears to establish relatively easily, although more so in warmer (i.e. Mediterranean) than in northern countries (e.g. Belgium, UK). Telemetry data suggest that dispersal is linked to flooding/spates and human translation of the species. Potential impacts in its introduced European range include disease transmission, hybridization (in Greece with native endemic Aristotle's catfish [Silurus aristotelis]), predation on native species and possibly the modification of food web structure in some regions. However, S. glanis has also been reported (France, Spain, Turkmenistan) to prey intensively on other non-native species and in its native Germany to be a poor biomanipulation tool for top-down predation of zooplanktivorous fishes. As such, S. glanis is unlikely to exert trophic pressure on native fishes except in circumstances where other human impacts are already in force. In summary, virtually all aspects of the environmental biology of introduced S. glanis require further study to determine the potential risks of its introduction to novel environments. [source]

Evaluation of a by-catch reduction device for glass eel fishing traps

FISHERIES MANAGEMENT & ECOLOGY, Issue 6 2009
M. A. LOPEZ
Abstract, The effectiveness of a new design of glass eel, Anguilla anguilla (L.), fishing trap was tested in the Ebro River delta fishery (Eastern Mediterranean, Spain). The modified fishing trap incorporated a by-catch reduction device (BRD) to increase trap selectivity and minimise by-catch of non-targeted fish, without affecting glass eel captures. The BRD is inexpensive and easy to implement, consisting of a cylinder covered with a rigid square-mesh of 2.0,2.4 mm knot-to-knot, which is easily fitted to the fishing trap entrance. Testing of the BRD was made by paired comparisons between captures of targeted and non-targeted fish species from both conventional and BRD-modified traps. The use of a BRD in the glass eel traps resulted in a 68.9% reduction in the number of captured non-targeted fish specimens, while it did not reduce glass eel yields. The BRD implementation was fully effective for all species and individuals with sizes >40 mm total length, with the exception of the black-striped pipefish, Syngnathus abaster Risso. These results support the implementation of the BRD in glass eel fisheries along the Eastern coast of the Iberian Peninsula where these fishing traps are used. [source]

The role of oceanographic conditions and plankton availability in larval fish assemblages off the Catalan coast (NW Mediterranean)

FISHERIES OCEANOGRAPHY, Issue 3 2010
M. PILAR OLIVAR
Abstract In the northwestern Mediterranean, most fish species reproduce in early summer and fewer in the autumn mixing period. This study analyses and compares larval fish assemblages (LFA) in both seasons, and is the first attempt to characterize LFA structure for the autumn period. We analyze horizontal and vertical distribution of fish larvae and the micro- and mesozooplankton biomass and abundance of the main zooplankton groups. The oceanographic situation was analyzed through the study of data from CTD, N,-Shuttle and ADCP surveys. LFA were determined by ordination analyses based on larval abundance, and the relationships between larval assemblages and environmental variables were investigated through canonical correspondence analysis. The importance of some hydrographic variables (temperature, salinity and stability of the water column), current fields (along-shelf and across-shelf transport) and the abundance of zooplankton are discussed as important factors shaping the structure of larval assemblages. In early summer, LFA were mainly structured by a combination of bathymetry and trophic components, although sea surface temperature also played a role in shaping the horizontal larval distributions. In autumn, trophic variables were the main factors influencing the shelf-dwelling species assemblage. Larvae of oceanic species, on the other hand, were not related to trophic variables but were more affected by current fields. [source]

Advection of anchovy (Engraulis encrasicolus) larvae along the Catalan continental slope (NW Mediterranean)

FISHERIES OCEANOGRAPHY, Issue 2 2007
A. SABATÉS
Abstract The Gulf of Lions is one of the main anchovy (Engraulis encrasicolus) spawning areas in the NW Mediterranean. During the spring, low-salinity surface water from the outflow of the Rhône is advected by the shelf-slope current along the continental slope off the Catalan coast. In June 2000, a Lagrangian experiment tracking these low-salinity surface waters was conducted to assess the importance of this transport mechanism for anchovy larvae and to determine the suitability of the tracked surface waters for survival of anchovy larvae. The experiment consisted of sampling the tracked water parcel for 10 days with three drifters launched at the core of the shelf-slope current where low-salinity surface waters were detected. The survey was completed by sampling the surrounding waters. Anchovy larvae from the spawning area in the Gulf of Lions were advected towards the south in the low-salinity waters. The size increase of anchovy larvae throughout the Lagrangian tracking closely followed the general growth rate calculated by otolith analysis (0.65 mm day,1). However, advection by the current was not the only mechanism of anchovy larval transport. A series of anticyclonic eddies, originated in the Gulf of Lions and advected southwards, seemed to play a complementary role in the transport of larvae from the spawning ground towards the nursery areas. These eddies not only contributed to larval transport but also prevented their dispersion. These transport and aggregation mechanisms may be important for anchovy populations along the Catalan coast and require further study. [source]

Spawning habitat and daily egg production of sardine (Sardina pilchardus) in the eastern Mediterranean

FISHERIES OCEANOGRAPHY, Issue 4 2006
S. SOMARAKIS
Abstract Spawning habitats of two eastern Mediterranean sardine, Sardina pilchardus (Walbaum, 1792), stocks (coastal waters of central Aegean and Ionian Seas) are characterized from daily egg production method (DEPM) surveys conducted during the peak of the spawning period. The latter occurs earlier in the Aegean Sea (December) than in the less-productive Ionian Sea (February). Single-parameter quotient analysis showed that the preferred bottom depth for spawning was 40,90 m in both areas but sardine selected sites of increased zooplankton in the Aegean Sea during December and increased fluorescence in the Ionian Sea during February. Estimates of daily egg production (P) and spawning stock biomass (B) were about four times lower for the Ionian Sea (P = 7.81 eggs m,2, B = 3652 tonnes) than the Aegean Sea (P = 27.52 eggs m,2, B = 16 174 tonnes). We suggest that zooplankton biomass might not be sufficient to support sardine reproduction in the highly oligotrophic Ionian Sea where the very small sardine stock may rely on the late-winter phytoplankton bloom. Actively selecting sites with increased zooplankton or phytoplankton and feeding plasticity (the well-known switching from selective particle feeding to non-selective filter feeding in sardines) are interpreted as adaptations to grow and reproduce optimally at varying prey conditions. Despite differences in temperature and productivity regimes, reproductive performance of sardine in the Ionian Sea was very similar to that in the Aegean Sea during the peak of the spawning period. In comparing adult parameters from DEPM applications to Sardina and Sardinops stocks around the world, a highly significant linear relation emerged between mean batch fecundity (F) and mean weight of mature female (W, g) (F = 0.364W, r2 = 0.98). The latter implies that, during the peak of the spawning period, mean relative batch fecundity (eggs g,1) of sardine is fairly constant in contrasting ecosystems around the world. [source]

Impact of freshwater input and wind on landings of anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) in shelf waters surrounding the Ebre (Ebro) River delta (north-western Mediterranean)

FISHERIES OCEANOGRAPHY, Issue 2 2004
J. Lloret
Abstract Time series analyses (Box,Jenkins models) were used to study the influence of river runoff and wind mixing index on the productivity of the two most abundant species of small pelagic fish exploited in waters surrounding the Ebre (Ebro) River continental shelf (north-western Mediterranean): anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus). River flow and wind were selected because they are known to enhance fertilization and local planktonic production, thus being crucial for the survival of fish larvae. Time series of the two environmental variables and landings of the two species were analysed to extract the trend and seasonality. All series displayed important seasonal and interannual fluctuations. In the long term, landings of anchovy declined while those of sardine increased. At the seasonal scale, landings of anchovy peaked during spring/summer while those of sardine peaked during spring and autumn. Seasonality in landings of anchovy was stronger than in sardine. Concerning the environmental series, monthly average Ebre runoff showed a progressive decline from 1960 until the late 1980s, and the wind mixing index was highest during 1994,96. Within the annual cycle, the minimum river flow occurs from July to October and the wind mixing peaks in winter (December,April, excluding January). The results of the analyses showed a significant correlation between monthly landings of anchovy and freshwater input of the Ebre River during the spawning season of this species (April,August), with a time lag of 12 months. In contrast, monthly landings of sardine were significantly positively correlated with the wind mixing index during the spawning season of this species (November,March), with a lag of 18 months. The results provide evidence of the influence of riverine inputs and wind mixing on the productivity of small pelagic fish in the north-western Mediterranean. The time lags obtained in the relationships stress the importance of river runoff and wind mixing for the early stages of anchovy and sardine, respectively, and their impact on recruitment. [source]

Climatic influences and anthropogenic stressors: an integrated framework for streamflow management in Mediterranean-climate California, U.S.A.

FRESHWATER BIOLOGY, Issue 2010
THEODORE E. GRANTHAM
Summary 1. In Mediterranean and other water-stressed climates, water management is critical to the conservation of freshwater ecosystems. To secure and maintain water allocations for the environment, integrated water management approaches are needed that consider ecosystem flow requirements, patterns of human water demands and the temporal and spatial dynamics of water availability. 2. Human settlements in Mediterranean climates have constructed water storage and conveyance projects at a scale and level of complexity far exceeding those in other, less seasonal climates. As a result, multiple ecological stressors associated with natural periods of flooding and drying are compounded by anthropogenic impacts resulting from water infrastructure development. 3. Despite substantial investments in freshwater ecosystem conservation, particularly in California, U.S.A., success has been limited because the scales at which river management and restoration are implemented are often discordant with the temporal and spatial scales at which ecosystem processes operate. Often, there is also strong social and political resistance to restricting water allocation to existing consumptive uses for environmental protection purposes. Furthermore, institutions rarely have the capacity to develop and implement integrated management programmes needed for freshwater ecosystem conservation. 4. We propose an integrated framework for streamflow management that explicitly considers the temporal and spatial dynamics of water supply and needs of both human and natural systems. This approach makes it possible to assess the effects of alternative management strategies to human water security and ecosystem conditions and facilitates integrated decision-making by water management institutions. 5. We illustrate the framework by applying a GIS-based hydrologic model in a Mediterranean-climate watershed in Sonoma County, California, U.S.A. The model is designed to assess the hydrologic impacts of multiple water users distributed throughout a stream network. We analyse the effects of vineyard water management on environmental flows to (i) evaluate streamflow impacts from small storage ponds designed to meet human water demands and reduce summer diversions, (ii) prioritise the placement of storage ponds to meet human water needs while optimising environmental flow benefits and (iii) examine the environmental and social consequences of flow management policies designed to regulate the timing of diversions to protect ecosystem functions. 6. Thematic implications: spatially explicit models that represent anthropogenic stressors (e.g. water diversions) and environmental flow needs are required to address persistent and growing threats to freshwater biodiversity. A coupled human,natural system approach to water management is particularly useful in Mediterranean climates, characterised by severe competition for water resources and high spatial and temporal variability in flow regimes. However, lessons learned from our analyses are applicable to other highly seasonal systems and those that are expected to have increased precipitation variability resulting from climate change. [source]

Across the Religious Divide: Women, Property, and Law in the Wider Mediterranean (ca.1300,1800) edited by Jutta Gisela Sperling and Shona Kelly Wray

GENDER & HISTORY, Issue 2 2010
EMMA LOOSLEY
No abstract is available for this article. [source]

The microstratigraphic record of abrupt climate changes in cave sediments of the Western Mediterranean

GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 5 2001
Marie-Agnès Courty
The purpose of this paper is to illustrate how calcareous sediments from Pleistocene and Holocene rockshelters and open caves of the Western Mediterranean can provide a stratigraphic record of abrupt climate change. The method proposed here is based on microstratigraphic examination of sedimentary sequences using microscopic techniques. The most important processes for characterizing the sensitivity of each cave to climate variables are: (1) the modes and rate of carbonate sediment production, (2) the nature and intensity of the pedogenic processes responsible for the synchronous alteration of carbonate materials (either those derived from the cave walls or those deposited on the ground surface), and (3) the supply of allogenic sediments, particularly by eolian activity. The cave sediment sequences presented record the marked coolings known as Dansgaard-Oeschger stadials and Heinrich events that occurred during the Pleistocene and the Holocene, as demonstrated by the high resolution records from ice and deep sea cores. At Abric Romanì in northeastern Spain, a series of sharp climatic deteriorations of increasing severity is shown to have occurred synchronously with the transition from the Middle to the Upper Paleolithic, with a period of seasonal frost and strong winds at ca. 37,000 yr B.P., tentatively correlated with Heinrich event 4. At Pigeon Cave, Taforalt (northern Morocco), the transition from the Aterian to Ibero-Maurusian/Epipalaeolithic cultures is dated to around 24,000,20,000 yr B.P. and is punctuated by a series of short cold pulses with evidence for seasonal freezing, soil erosion, and minimal evapotranspiration. In El Miron cave in north-central Spain, the exceptional nature of the Younger Dryas cooling produced a marked destabilization of the cave walls and roof. At El Miron, the stratigraphic evidence for sediment removal due to the rapid percolation of snow melt under a degraded soil cover allows us to reconstruct the nature of the negative excursion at ca. 8200 yr B.P. This example also illustrates how climate-controlled pedogenic processes can create a stratigraphic signature which has often been confused with a sedimentary hiatus. We conclude that cave sediments provide a valuable record of Pleistocene and Holocene climate changes. In appropriate contexts, these sequences allow us to examine the ecological stress generated by these unique global events at a local and regional level and improve our understanding of the complex anthropological processes that occurred at the same time. © 2001 John Wiley & Sons, Inc. [source]

Ribosomal RNA gene fragments from fossilized cyanobacteria identified in primary gypsum from the late Miocene, Italy

GEOBIOLOGY, Issue 2 2010
G. PANIERI
Earth scientists have searched for signs of microscopic life in ancient samples of permafrost, ice, deep-sea sediments, amber, salt and chert. Until now, evidence of cyanobacteria has not been reported in any studies of ancient DNA older than a few thousand years. Here, we investigate morphologically, biochemically and genetically primary evaporites deposited in situ during the late Miocene (Messinian) Salinity Crisis from the north-eastern Apennines of Italy. The evaporites contain fossilized bacterial structures having identical morphological forms as modern microbes. We successfully extracted and amplified genetic material belonging to ancient cyanobacteria from gypsum crystals dating back to 5.910,5.816 Ma, when the Mediterranean became a giant hypersaline brine pool. This finding represents the oldest ancient cyanobacterial DNA to date. Our clone library and its phylogenetic comparison with present cyanobacterial populations point to a marine origin for the depositional basin. This investigation opens the possibility of including fossil cyanobacterial DNA into the palaeo-reconstruction of various environments and could also be used to quantify the ecological importance of cyanobacteria through geological time. These genetic markers serve as biosignatures providing important clues about ancient life and begin a new discussion concerning the debate on the origin of late Miocene evaporites in the Mediterranean. [source]

History of Deforestation and Reforestation in the Dinaric Karst

GEOGRAPHICAL RESEARCH, Issue 1 2009
ANDREJ KRANJC
Abstract The term karst derives from the Kras plateau, which is in the northwestern part of the area now known as the Dinaric Karst. The landscape consists mostly of Mesozoic carbonate rocks and stretches along the Adriatic Sea coast for a distance of 600 km. Although the region lies parallel to the sea, the Mediterranean temperature influence is limited to a narrow coastal belt, except for the amount of precipitation, which can reach 5000 mm yr,1. Forests belonging to the Mediterranean and Euro-Siberian , North American region, covered the primary Dinaric Karst. Human deforestation of the Karst began during the Neolithic period, 6500,6000 BC. Throughout history there have been two main reasons for deforestation; economic (the requirements of new land, pastures, timber use and trade), and social (local increases in population, mass migration, wars, raids). Mankind's perception of forest protection and preservation can be traced through documents going back to the 12th century. Reforestation is mentioned in some of them, but successful reforestation did not begin until the 1850s. Nowadays dense natural forests, extensive forest plantations, dry karst shrublands and also completely barren karst areas can all be found on the Dinaric Karst. [source]

Late Miocene fish otoliths from the Colombacci Formation (Northern Apennines, Italy): implications for the Messinian ,Lago-mare' event

GEOLOGICAL JOURNAL, Issue 5 2006
Giorgio Carnevale
Abstract A fish otolith assemblage from the Messinian ,Lago-mare' deposits of the Colombacci Formation cropping out in the Montecalvo in Foglia Syncline, Marche, central Italy, is described. The assemblage displays a low diversity and consists of seven taxa belonging to three families: the Gobiidae, Myctophidae and Sciaenidae. Sciaenid otoliths are the most abundant elements representing 88% of the entire assemblage. The palaeoecological analysis reveals a coastal shallow marine environment strongly influenced by continental outflow. The low diversity and high abundance of the euryecious sciaenids are indicative of a very simplified food web, which probably represented an ecological response to the fluctuating environmental parameters and available food resources. The fish remains documented here provide an unambiguous evidence that normal marine conditions were present in the Mediterranean, at least in the upper part of the ,Lago-mare' event, and unquestionably demonstrate that the marine refilling preceded the Mio-Pliocene boundary. These findings clearly demonstrate that fishes, because of their mobility and migratory behaviour, represent a useful tool for the large-scale interpretation of the environmental conditions of the Messinian Mediterranean water body. The necessity of a new scenario of palaeoenvironmental evolution for the post-evaporitic Messinian of the Mediterranean is also discussed. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Ostracode faunas of bottom sediments from the continental shelf, south Marmara Sea, NW Turkey, and their comparison with other shelf environments in the Mediterranean and Aegean regions

GEOLOGICAL JOURNAL, Issue 2 2001
Atike Nazik
Abstract This study describes the ostracode faunal composition and distribution on the continental shelf of the southern Marmara Sea in Turkey. Twenty-three bottom samples were collected from the shelf. These samples are characterized by silt-clay (mud), sand and gravel in the studied area. A total of 46 species belonging to 32 genera were determined from these samples. Seven species were dominant from 46 ostracode species. Three assemblages were identified by their dominant species. These are characterized by: Costa edwardsii (Roemer); a mixed assemblage which consists of Cytheridea neapolitana Kollmann, Pterygocythereis ceratoptera (Bosquet), Tegmenia rugosa (Costa), Acanthocythereis hystrix (Reuss) and Xestoleberis communis (G.W. Müller); and Aurila convexa (Baird). The relations between the dominant species, lithology and CaCO3 concentration have been investigated, and the results are compared with other shelf environments within the Mediterranean and Aegean regions. Pterygocythereis, Costa, Tegmenia and Cytheridea are abundant in muddy substrates; Aurila and Acanthocythereis are abundant in sandy substrates. Acanthocythereis hystrix (Reuss), Aurila convexa (Baird), Buntonia subulata Ruggieri, Carinocythereis antiquata (Baird), Carinocythereis carinata (Roemer), Costa batei (Brady), Costa edwardsii (Roemer), Cytheridea neapolitana Kollmann, Celtia quadridentata (Baird), Loxoconcha rhomboidea (Fischer), Pterygocythereis jonesii (Baird) and Semicytherura acuticostata (Sars) are common, and similar species are recorded from other continental shelves of the Mediterranean. Copyright © 2001 John Wiley & Sons, Ltd. [source]