Reproductive potential of silver European eels (Anguilla anguilla) migrating from Vistonis Lake (Northern Aegean Sea, Greece)

The European eel (Anguilla anguilla), once abundant throughout much of Europe and North Africa, has recently been classified as critically endangered. Information on its biology from the eastern Mediterranean is lacking, especially in relation to spawner quality. Therefore, silver eels were sampled during their seaward spawning migration from Vistonis Lake in Greece. Characteristics linked to reproductive output and success (i.e. body size and condition, sex ratio, silvering, Anguillicola crassus infection, fecundity and oocyte diameter) were examined. The lake produced large (687–1138 mm), exclusively female silver eels, 61.7% of which were infected by A. crassus. Silver eel fecundity, the first estimates from the southern part of the species range, was positively related to body length (R2 = 0.693; P < 0.001) and body weight (R2 = 0.731; P < 0.001). Fecundity did not differ between A. crassus infected and uninfected silver eels, but Greek silver eels were significantly more fecund than those in north-west Europe. The reproductive potential of Vistonis Lake silver eels and their contribution to the A. anguilla spawning stock is discussed.

Chemical Characterization and Source Apportionment of Household Fine Particulate Matter in Rural, Peri-urban, and Urban West Africa

Household air pollution in sub-Saharan Africa and other developing regions is an important cause of disease burden. Little is known about the chemical composition and sources of household air pollution in sub-Saharan Africa, and how they differ between rural and urban homes. We analyzed the chemical composition and sources of fine particles (PM2.5) in household cooking areas of multiple neighborhoods in Accra, Ghana, and in peri-urban (Banjul) and rural (Basse) areas in The Gambia. In Accra, biomass burning accounted for 39–62% of total PM2.5 mass in the cooking area in different neighborhoods; the absolute contributions were 10–45 μg/m3. Road dust and vehicle emissions comprised 12–33% of PM2.5 mass. Solid waste burning was also a significant contributor to household PM2.5 in a low-income neighborhood but not for those living in better-off areas. In Banjul and Basse, biomass burning was the single dominant source of cooking-area PM2.5, accounting for 74–87% of its total mass; the relative and absolute contributions of biomass smoke to PM2.5 mass were larger in households that used firewood than in those using charcoal, reaching as high as 463 μg/m3 in Basse homes that used firewood for cooking. Our findings demonstrate the need for policies that enhance access to cleaner fuels in both rural and urban areas, and for controlling traffic emissions in cities in sub-Saharan Africa

Residential exposure to motor vehicle emissions and the risk of wheezing among 7-8 year-old schoolchildren: a city-wide cross-sectional study in Nicosia, Cyprus

<p>Abstract</p> <p>Background</p> <p>Several studies have reported associations between respiratory outcomes in children and a range of self-reported, administrative or geographical indicators of traffic pollution. First-time investigation into the frequency of asthmatic symptoms among 7-8 year-old Cypriot children in 1999-2000 showed increased prevalence in the capital Nicosia compared to other areas. Geographical differences on an island the size of Cyprus may reflect environmental and/or lifestyle factors. This study investigates the relationship between self-reported symptoms and residential exposure to motor vehicle emissions among Nicosia schoolchildren.</p> <p>Methods</p> <p>The addresses of children in the metropolitan area of Nicosia who participated in the original survey (N = 1,735) were geo-coded and the level of exposure of each child was assessed using distance- and emission-based indicators (i.e. estimated levels of particulate matter and nitrogen oxides emissions due to motor vehicles on main roads around the residence). Odds ratios of wheezing and asthma diagnosis in relation to levels of exposure were estimated in logistic regression models adjusting for person-based factors, co-morbidity and intra-school clustering.</p> <p>Results</p> <p>We found an increased risk of wheezing at distances less than 50 m from a main road and/or only among those experiencing the highest levels of exposure. The strongest effect estimates were observed when exposure was defined in terms of the cumulative burden at all roads around the residence. Adjusted odds ratios for current wheezing were 2.33 (95% CI 1.27, 4.30) amongst the quartile of participants exposed to the highest levels of PM at all roads 50 m of their residence and 2.14 (95% CI 1.05, 4.35) for NOx, with no effect at intermediate levels of exposure. While the direction of effect was apparent at longer distances, differences were generally not statistically significant.</p> <p>Conclusions</p> <p>Children experiencing the highest burden of emissions in Nicosia seem to be at a higher risk of reporting asthmatic symptoms. Due to the small number of children residing at close proximity to main roads and lack of evidence of risk at intermediate levels of exposure or longer distances, the observed pattern alone does not explain the generally higher prevalence observed in urban Nicosia compared to other areas.</p

Summer fish larval assemblages and station groups in the northern Aegean Sea

Fish larvae were collected in two surveys, carried out at the beginning of July 2002 and 2003 in Kavala Gulf (northern Aegean Sea) aimed at studying ichthyoplankton species assemblages and station groupings. The similarity dendrograms revealed the existence of four species assemblages associated with three station groups in 2002 and five species assemblages associated with four station groups in 2003. These groupings were confirmed by non-metric multidimensional scaling (NMDS) analysis. Analysis of similarity showed that the station groups were significantly different for 2002 (global R=0.748; P<0.001) and 2003 (global R=0.931; P<0.001). High dissimilarity between species assemblages as obtained from dendrograms and NMDS analyses was also recorded for 2002 (global R=0.834; P<0.001) and 2003 (global R=0.767; P<0.001). The assemblage structure was mainly determined by the most abundant and frequently occurring larvae, especially the European anchovy (Engraulis encrasicolus), and was largely influenced by the reproductive traits and spatial distribution of adult fish. Differences among station groupings were also determined by the spatial occurrence and abundance of each taxon

Reproductive biology of the marbled goby, Pomatoschistus marmoratus (Pisces, Gobiidae), in a northern Aegean estuarine system (Greece)

The reproductive biology of the marbled goby, Pomatoschistus marmoratus (Risso, 1810), was studied in the Strymon River estuarine system (northern Greece) between September 1997 and August 1999. Samplings were conducted on a monthly basis at the Mouth of the river using a bag seine net and overall a total of 4 563 individuals were collected. The total length of males ranged between 2.5 and 6.0 cm and that of females between 2.9 and 5.7 cm, while that of unsexed individuals ranged between 1.2 and 2.9 cm. Sex ratio was 1.54:1 in favour of the females and statistically different from unity. The spawning of the species was extended. occurring between February and May. Mean absolute fecundity (F) was 1 386 (SE = 8) oocytes and showed a significant positive exponential relationship with total length (F = 14.387TL(2.92)). and total weight (F = 1351TW(0.83)) of the fish. The relative fecundity ranged between 878 and 3444 oocytes/g of total weight. Mean size at first maturity was estimated at 3.82 cm for the females and 4.66 cut for the males