Spatial variability in reproductive cycle of the gorgonians <Emphasis Type="Italic">Paramuricea clavata</Emphasis> and <Emphasis Type="Italic">Eunicella singularis</Emphasis> (Anthozoa,Octocorallia) in the Western Mediterranean Sea

Paramuricea clavata (Risso, 1826) and Eunicella singularis (Esper, 1794) are the most representative gorgonian species in hard bottoms sublittoral communities in the Western Mediterranean Sea. Reproductive cycles of two populations of both species were studied in two distinct locations approximately 600 km apart (Medes Islands and Cape of Palos), in order to assess interpopulation variability on a relevant geographic scale. Seasonal variation of lipid concentration levels in the gorgonian tissue was used as a tool to quantify energy storage by each studied population in order to explain possible interpopulation differences in gonadal output. Sex ratio in Medes Islands populations of both species was 1:1, while in Cape of Palos sex ratio was significantly male biased (1:7) in P. clavata, and female biased (1.7:1) in E. singularis populations. Spawning timing occurred in all cases coinciding with a marked increase in sea-water temperature in spring, and after the most successful feeding season, but comparing localities there was a clear temporal shift in the time of gametes release, appearing well linked to the shift in sea-water temperature rising in spring in both sites at the depth where populations are placed. Therefore, in this study the temperature appears as the main synchronizing factor of gonadal development within these populations. Significant differences in gonadal volume per polyp were found in both species owing mainly to differences in the number of gonads per polyp between populations, with Cape of Palos populations displaying higher values in both studied species, suggesting that the exposition to different local conditions may be reverted in a different gonadal output. But the observed patterns in lipid concentrations levels in gorgonians disable us to conclude that lipid concentration levels explain the observed differences in gonadal output found in this study.     

Effects of spatial variability and colony size on the reproductive output and gonadal development cycle of the Mediterranean red coral (Corallium rubrum L.)

Red coral (Corallium rubrum, L. 1758) is an over-exploited Mediterranean gorgonian. The gonadal development cycle of this gorgonian is examined at the Costa Brava (NW Mediterranean) taking into account for the first time colony size, depth and spatial horizontal variability. This study compares the gonad development and fertility in two colony size classes (colonies <6-cm height, and >10-cm height, both at 40–45-m depth), and two populations at different depths (16–18-m depth, and 40–45-m depth, both consisting of <6-cm high colonies) in a 15-month period. The fertility of seven size classes (<2 cm to >12 cm high colonies, in 2 cm intervals) was examined in the deep population, where large colonies were present. Furthermore, reproductive output was compared in 6 populations (distributed along more than 70-km coastline) one month before spawning (June). Red coral was found to be dioecious and gonochoric with a sex ratio of 1:1, which differs from other NW Mediterranean populations. On the other hand, fertility of different size classes indicates that small colonies of 2-cm height already produce gonads, which is in line with previous studies. Female and male polyp fertility and sperm sac size increase significantly with colony size [sperm sac diameter: 476±144 μm (mean±SD) and 305±150 μm in the >10-cm and <6-cm height colonies, respectively), whereas no significant effect on oocyte diameter was found (oocyte diameter: 373.7±18.7 μm). Depth staggered spawning, that is, an earlier release of gonads in the shallow populations, was observed in summer 2003, coinciding with the highest temperature gradient between shallow and deep water during the study period. Colonies of <6-cm height were significantly less fertile than colonies >12 cm, thus the recommendation of this study is that a minimum height should be incorporated into fishing regulations. The six studied populations at the Costa Brava showed a comparable reproductive potential, which demonstrates little variability within the homogenous population structure and range of size classes (due to overharvesting) found at the Costa Brava. The study of reproductive output is an important tool for ecosystem management, and this work recommends basing specific exploitation laws for distinctive populations on colony size, which is found to have a larger effect on reproductive potential than mesoscale variability. An erratum to this article can be found at     

Population structure of an exploited benthic cnidarian: the case study of red coral (Corallium rubrum L.)

Octocorals are an important part of many ecosystems as they add three-dimensional complexity to the benthos and thereby increase biodiversity. The Mediterranean red coral (Corallium rubrum, L. 1758) is a longevous octocoral that is harvested commercially, yet natural and anthropogenic influences on its population size structure are little understood. This study found that some harvested red coral populations had a significantly different size structure when compared to populations at the nearby Marine Protected Area (MPA) of Medas Islands at the Spanish Costa Brava (NW Mediterranean). Eighty-nine percent of the red corals in the harvested Costa Brava area are less than 10 years old and 96% of all colonies have not yet grown more than second-order branches. The size/age distribution of the harvested population is notably skewed towards younger and smaller colonies. Thus, although red coral is still abundant, its population structure is strongly distorted by harvesting. The results confirm that MPAs are useful to distinguish between anthropogenic and natural influences on population structure. However, 14 years of protection appears to be an insufficient recovery time for a longevous octocoral population such as red coral.     

Waste management health risk assessment: A case study of a solid waste landfill in South Italy

An integrated risk assessment study has been performed in an area within 5 km from a landfill that accepts non hazardous waste. The risk assessment was based on measured emissions and maximum chronic population exposure, for both children and adults, to contaminated air, some foods and soil. The toxic effects assessed were limited to the main known carcinogenic compounds emitted from landfills coming both from landfill gas torch combustion (e.g., dioxins, furans and polycyclic aromatic hydrocarbons, PAHs) and from diffusive emissions (vinyl chloride monomer, VCM). Risk assessment has been performed both for carcinogenic and non-carcinogenic effects. Results indicate that cancer and non-cancer effects risk (hazard index, HI) are largely below the values accepted from the main international agencies (e.g., WHO, US EPA) and national legislation (D.Lgs. 152/2006 and D.Lgs. 4/2008).     

Cytogenetic analysis of Oedalechilus labeo (Pisces: Mugilidae), with a report of NOR variability

 A cytogenetic analysis by several staining techniques was carried out on Oedalechilus labeo specimens from the west coast of Italy, in order to extend the karyological knowledge on Mediterranean mullets. The karyotype of the species is composed of 46 acrocentric and 2 subtelocentric chromosomes. Constitutive heterochromatin was found to be restricted to the centromeres. Fluorochrome staining revealed a uniform base composition along the chromosome arms. Nucleolus organizer regions (NORs) are located on the short arms of chromosome pair 9 and can be either homomorphic or quite heteromorphic in size. In some specimens chromomycin A₃-staining and fluorescence in situ hybridization with 18S rDNA revealed a third additional and inactive NOR on the short arms of a medium-sized chromosome. This is the first report of NOR variability in Mugilidae, a family generally characterized by a quite conservative karyotype. Heterochromatin composition and NOR location differentiate O. labeo from a cytotaxonomical point of view from the Liza species studied, Liza being considered the genus from which the genus Oedalechilus derived. Received: 10 April 1999 / Accepted: 21 October 1999     

Numerical simulation of scalar dispersion downstream of a square obstacle using gradient-transport type models

We present a numerical study of scalar transport released from a line source downstream of a square obstacle to investigate the capabilities and limitations of gradient-transport modeling in predicting atmospheric dispersion. The standard k–? and k–ω models and a Reynolds Stress Transport closure are employed and compared to predict the time-averaged turbulent flow field, while a standard gradient–diffusion model is initially adopted to relate the scalar flux to mean gradients of the concentration field. The analysis of two algebraic closures for turbulent scalar fluxes based on the generalized-gradient–diffusion hypothesis and its quadratic extension is also presented. In spite of the rather simple flow setup, where both the flow and the scalar fields can be assumed homogeneous in the spanwise direction, the analysis clarifies several critical issues concerning gradient-transport type models. We established the dominant role of predicted turbulent kinetic energy on scalar dispersion when a scalar diffusivity is employed, irrespectively of the Reynolds stress closure adopted for the averaged momentum equation. Moreover, the standard gradient–diffusion hypothesis failed to predict the streamwise component of the scalar flux, which is characterized by a counter-gradient-transport mechanism. Although the resulting contribution in the averaged scalar transport equation is small in the present flow configuration, this limitation can become severe for strongly inhomogeneous flows in the presence of point sources, where the spread of the scalar plume is essentially three-dimensional. The predictive capabilities of gradient-transport type modeling are found clearly improved using algebraic closures, which appear to represent a promising tool for predicting atmospheric dispersion in complex flows when unsteady transport mechanisms are not dominant.     

Drinking water quality: An in vitro approach for the assessment of cytotoxic and genotoxic load in water sampled along distribution system

An in vitro approach was performed to assess the quality of drinking water collected at two treatment/distribution networks located near the source (Plant #1) and the mouth of River Po (Plant #2). The water was sampled at different points of each distribution network, before (raw water) and after the chlorine dioxide disinfection, and in two points of the pipeline system to evaluate the influence of the distribution system on the amount and quality of the disinfection by-product. Cytotoxicity and genotoxicity of water extracts were evaluated in human peripheral lymphocytes and Hep-G2 cells by the use of the micronucleus (MN) test and Comet assay. Raw water samples of both plants induced cytotoxic effects, but not the increases of MN frequency in Hep-G2 cells and in human lymphocytes. Increases of DNA damage in human leukocytes was detected by Comet assay for raw water of Plant #2 at concentration ≥ 0.25 Leq/mL. The disinfection process generally has reduced the toxicity of water samples, even if potential direct DNA-damaging compounds have been detectable in drinking water samples. The proposal approach, if currently used together with chemical analysis, can contribute to improve the monitoring drinking water.     

Real-life efficiency of urine source separation

Urine source separation (NoMix technology) is a promising innovation in wastewater management. To improve and further develop NoMix technology, it has been implemented in four Swiss households and at our research institute (Eawag). We conducted measurements during one year on frequency of toilet usage (in households 5.2/person/day for weekdays, and 6.3/person/day for weekends), flushing behavior (30–85% small flushes), and recovered urine. We calculate the amount of urine effectively recovered per voiding in NoMix toilets (138 ml/flush in households; 309 ml/flush in women's toilets at Eawag), and waterfree urinals (225 ml/usage). We estimate urine recovery in the households to be maximally 70–75% of the expected quantity, leaving room for technical and behavioral improvements. Based on sampling of N and P concentrations, we suspect nitrogen losses in the extended urine piping system. For households and workplaces, the daily and weekly flushing pattern is recorded. Our results are in accordance with literature data from a shorter period but with more people. These results represent a good dimensioning basis for future urine source separation applications. An example of extrapolation to an entire watershed is presented. The flushing pattern corresponds well with the typical nitrogen loading of a treatment plant.     

Assessment of compost quality for its environmentally safe use by means of an ecotoxicological test on a soil organism

A research project was carried out to evaluate toxicological effects of compost addition to agricultural soil using the earthworm Eisenia foetida (Annellida) as a representative organism of the soil fauna. Moreover, the correlation between compost biochemical stabilization and toxicity at different phases of the composting process was assessed. Samples were collected from three composting plants at three different maturation levels (beginning of the composting process, intermediate compost after bio-oxidation, and mature refined compost). Two tests were performed: a standard chronic solid-phase test and an acute solid-phase test (developed originally by the authors). In the first test, the measured end-points were mortality, growth and reproduction; while in the second test earthworms’ behavior was evaluated. The chosen compost concentrations in soil ranged from 2.5 to 100 %, with the aim of obtaining the toxicological parameters (LC50) and to mimic real agricultural dosages for the lower concentrations. Results indicated an increase in compost toxicity with greater compost concentrations; in particular, agricultural compost dosage below 10 % showed no toxicity. Moreover, toxicity did not decrease during composting; intermediate compost showed the highest LC50 values. As a consequence, no correlation was ascertained between the results of ecotoxicological analysis and waste biochemical stability parameters during the composting process.