Structural and functional response of meiofauna rocky assemblages to sewage pollution

Despite meiofauna being one of the most popular tool for detecting the ecological effects of different sources of impact, the application of structured experimental designs to this benthic component is typically neglected, especially in subtidal rocky shores. In this study, an asymmetrical design was used to detect hard-bottom meiofaunal abundance and biodiversity response to sewage discharge. Sampling was carried out at a depth of 3-4 m by SCUBA diving, by means of a modified manual corer. Six replicate cores were collected at three sites (80-100 m apart), at each of three locations (one purportedly impacted [I] and two controls [Cs]). A total of 84,994 specimens were collected. The outfall affected meiofaunal assemblages in terms of taxon richness, by determining a significant reduction of the number of taxa in the disturbed location, and community structure, by causing functional changes in terms of a decrease of the abundance of nematodes and an increase of the hydrozoan component. Nematodes and syllid polychaetes showed significant lower average abundance at I. Multivariate analyses showed that both meiofaunal assemblage and syllids were significantly different at I compared with Cs. The sewage outfall also affected patterns of spatial distribution at the scale of site (100 m apart) and of replicate units (centimetres apart), both in syllids and in nematodes. Our results provide evidence that the selection of multiple controls is crucial to prevent the widespread risk of Type II error, highlighting the need of more accurate experimental designs when dealing with meiofauna.     

Conservation of Mediterranean seascapes: analyses of existing protection schemes

Marine protected areas (MPAs) are aimed at managing and protecting marine environments. Their design, however, often disregards both a thorough knowledge of the distribution of habitats and assemblages and the use of proper experimental evaluations of the efficacy of MPAs by comparing protected vs. unprotected zones. About 200 MPAs have been recently instituted in the Mediterranean area, but the evidence of their efficacy is scant. The MPA of Torre Guaceto (Southern Adriatic Sea, Italy) is one of the rare cases of effective protection enforcement. The reserve was instituted more than 10 years ago, a period currently considered as sufficient to show responses by organisms to protection. The MPA is divided into a C zone, the general reserve, where many activities are permitted, a B zone, the partial reserve where restrictions increase and two A zones, the integral reserve where access is prohibited. The goals of the paper were to map the distribution of benthic assemblages to assess if they were properly represented in the differently protected zones, and to test the efficacy of protection by quantifying possible differences between the assemblages in two control areas and in the two A zones, where human impact is completely excluded. The analysis of habitat and assemblage distribution within the MPA showed that the zones with total protection do not include most valuable environmental types. Most of the considered variables (i.e. cover of substratum, number of taxa, and average abundance of the most common taxa) were not significantly different in and out of the A zones, at each time of sampling. Results, however, suggested a possible effect of protection in modifying patterns of abundance of sponges under Cystoseira canopy (more abundant in the fully protected zone). In the subtidal habitat, differences were found in the structure of the whole assemblage and in the abundance of encrusting coralline red algae (more abundant outside the fully protected area). Notwithstanding the correct general methodology employed in the study, a lack of statistical power could have a role in preventing the detection of ecologically relevant effects of protection. In some instances, data pooling allowed a discrimination between cases where there was clearly no effect of protection and cases where there might be. On this basis, the optimization of this experimental design should be considered in further studies. In any case, if the goals of MPAs have not been clearly stated, efficacy of protection might prove very difficult to test even with the use of sound experimental designs.     

Coastal fish indicate human-induced changes in the Mediterranean littoral.

Coastal fish assemblages were studied to assess two sorts of human impacts in southwestern Apulia (SE Italy, Mediterranean Sea). Fish assemblages were evaluated by visual census along two rocky locations impacted by a sewage outfall discharging nearshore (S) and by date-mussel (Lithophaga lithophaga) fisheries (F), respectively, and at two control locations (Cs). Multivariate analyses showed that fish assemblage structures at S and F differed from those at Cs. Asymmetric ANOVAs indicated that species richness were significantly lower both at S (approximately 27%) and at F (approximately 35%) compared with Cs. Total fish abundance was 5- to 7-fold higher at S than at Cs, while the values recorded at F were comparable to those of Cs. At S, average abundances of planktivorous fish and POM feeders were higher, and those of labrids and sparids of the genus Diplodus were lower, respectively, than at Cs. Labrids of the genus Symphodus and small serranids were significantly less abundant at F than Cs. Data suggested that coastal fish respond to the impact caused by the sewage discharge and provided a framework to assess potential benefits of its future displacement to deeper waters. For the first time, moreover, this study provided suggestive evidence that the habitat destruction caused by the illegal date-mussel fisheries may affect fish assemblages.     

Perfluorinated compounds in blood of Caretta caretta from the Mediterranean Sea

Perfluorinated compounds (PFCs), widely used for their hydro-oil repellent properties, are almost non-degradable in the environment; there is scientific evidence that indicate bioaccumulation. They represent a threat to many organisms, because they are toxic and are endocrine disruptors. Scientific studies have demonstrated the presence of PFCs in blood and liver samples of fish, turtles, birds and mammals of marine ecosystems in different geographical areas. The aim of this study was to determine the distribution of PFOS and PFOA in blood samples of the marine turtle Caretta caretta, using a minimally invasive sampling procedure. 49 blood samples of marine turtle, taken from several Italian marine turtle rescue centers, were analyzed. While PFOA was never detected, measurable concentrations of PFOS were found in 15 blood samples; the values show a range from 1.14 ng/g to 28.51 ng/g (wet wt.). No differences between groups of samples taken from different areas were found.     

The effects of sewage discharge on shallow hard substrate sessile assemblages

On rocky shores, sewage discharges can modify natural distribution patterns of sessile organisms. The impact of sewage on shallow hard substrate assemblages has been assessed along SW Apulian coast (Ionian Sea, Italy), providing a framework to evaluate the benefits of future sewage displacement to deeper waters. Four locations (three controls and one putatively impacted) were selected and three sites were chosen at each location. Each site was sampled by 10 replicate photographic records. Univariate analyses revealed that the outfall did not affect the spatial distribution of number of taxa, total cover and abundance of some dominant taxa (mostly algae, sponges and bryozoans). The outfall negatively influenced the natural distribution pattern of filamentous green algae, whilst some algae (i.e. Gelidiales and Colpomenia sinuosa) were exclusively present at the impacted location. Multivariate analyses revealed that the outfall heavily modified the natural pattern of variability in the structure of the assemblage.     

Implications of a combined biostratigraphic and palaeomagnetic study of the Umbrian Maiolica Formation

The study of a 275.5 m thick section of white, pelagic limestones occupying the valley of the Fonte del Giordano river on the southern slope of Mt. Montagnola has yielded a biostratigraphically controlled clear magnetic reversal pattern after thermal cleaning. The magnetic stratigraphy of the lower 131 m of the section (Calpionellid zones) is correlatable with the M-sequence of oceanic magnetic anomalies between M-19 and M-14. The reversal stratigraphy of the upper 81.5 m of the section (Radiolaria zone) has also been tied to the oceanic polarity time scale by making linear interpolation for a missing 63 m thickness underneath it.Besides the Fonte del Giordano section two Berriasian outcrops each with a different bedding attitude were studied at Gubbio and near Cagli for tectonic tilt test giving positive results. The mean palaeomagnetic pole position for the Late Jurassic/Early Cretaceous after bedding correction is: Φ = 19.1°, Λ = 288.2°, k = 148.7, α₉₅ = 10.2° (N = 3), confirming the presence of a large swing in the polar path, a common behaviour of apparent polar wandering for the peri-Adriatic region during this time.