Medium-term impacts of hydraulic clam dredgers on a macrobenthic community of the Adriatic Sea (Italy)

Hydraulic dredging targeting the bivalve Chamelea gallina in the northern and central Adriatic Sea has been taking place for over 30 years. In the period 2000–2001, 73 commercial dredgers harvested the resource within the sandy coastal area of the Ancona Maritime District (central Adriatic Sea). Despite this, no study aimed at investigating the impact of the fishery on the macrobenthic community of the area has ever been carried out. Sampling was done at 6 monthly intervals in an attempt to relate the impact of hydraulic dredging to different levels of fishing intensity. Data regarding two depth strata (4–6; 7–10 m) were analysed separately by means of permutational multivariate analysis of variance. The results revealed an overall condition of moderate disturbance within the benthic community, especially so within the 4–6 m depth stratum. The response of the benthic community to varying intensities of fishing activity was rapid, occurring within 6 months. Differences in the response of benthic community to differing intensities of fishing activity were found between the two depth strata considered. Significant differences in multivariate location of the benthic community were revealed between the three disturbance levels in both depth strata. Differences in multivariate dispersion were detected above a threshold level of fishing intensity, only within the shallow community. Differences were found between depth strata relating to species diversity and evenness, with significant differences between levels of fishing intensity being evident only within the 4–6 m depth stratum. The results emphasised that, even in a benthic community that is typical of a moderately disturbed environment, the effects of fishing on community structure were still discernible over and above the natural variation.     

Shortfalls in minerals investments

The international minerals industry continues to have a substantial investment shortfall. The widening exploration and mineral development gaps, not only in the lesser developed countries but also in the developed nations, are sowing the seeds for future mineral supply disruptions and conflicts. Mutuality of interests demands concerted initiatives, individual as well as collective, to reverse the investment trends established by international mineral finance and the multinational corporations in order to pave the way for secure mineral supplies in the future at acceptable prices.     

Establishing the Canadian Community Monitoring Network

Community-based ecosystem monitoring activities in Canada are increasing in response to a number of factors including: (i) the needs of decision-makers for timely information on local environmental changes; (ii) limited use of government monitoring data and information by decision makers; (iii) government cuts to monitoring programs; (iv) the increasingly recognized need to include stakeholders in planning and management processes; and (v) the desire of citizens to contribute to environmental protection. To date there has been no network coordination of community based monitoring in Canada. This paper reports on the establishment of the Canadian Community Monitoring Network by Environment Canada's Ecological Monitoring and Assessment Network Coordinating Office and the Canadian Nature Federation. Information on research prepared in support of network establishment is presented along with a discussion of the potential of the network.     

Lack of evidence for nepotism by workers tending queens of the polygynous termite <Emphasis Type="Italic">Nasutitermes corniger</Emphasis>

Kin selection theory predicts that workers in social insect colonies should preferentially aid close relatives over less related or unrelated individuals if such behaviors increase inclusive fitness. For example, a worker in a polygynous (multiple-queen) colony is predicted to tend its own mother rather than an unrelated queen if this nepotistic behavior increases its mother’s reproductive success in excess of costs. Despite predictions, experimental tests conducted in the social Hymenoptera have found no clear evidence of nepotism. No tests for nepotism have been carried out in the Isoptera (termites), another major insect taxon showing highly developed sociality. We tested for nepotistic behavior in the termite Nasutitermes corniger by determining if workers preferentially fed and groomed their mothers in a laboratory assay. We collected workers from nine naturally occurring multiple-queen colonies as they tended queens and determined their parentage using highly variable microsatellite markers. Our results provide no evidence that workers tend their mothers in preference to co-occurring queens. The absence of evidence for nepotism is consistent with previous results reported from numerous studies of eusocial hymenopterans.     

Factors affecting vapour production in large scale evaporating liquid cascades

This paper presents a computational fluid dynamics (CFD) model of the evaporating liquid cascade produced in a large hydrocarbon storage tank overfilling incident. The model is first validated against the results of a unique series of full-scale experiments, in which liquid hexane was released from a 10 m high tower. Comparisons are presented for the temperature of both the liquid and vapour in the cascade, and the temperature of the vapour current. The validated model is then used to investigate the effects of different tank bund configurations, and the influence of an accumulating vapour layer on the vapour production process.     

Blast damage to storage tanks and steel clad buildings

The 2005 Buncefield vapour cloud explosion showed the huge cost associated with blast damage to commercial property surrounding a major explosion incident. In most cases there was serious disruption to business activity; in many cases the buildings had to be demolished or abandoned for long periods until extensive repairs were carried out.Another key feature of this and other recent vapour cloud explosions has been the damage done to storage tanks. The blasts almost invariably cause immediate top and bund fires in any tanks surrounded by the vapour – even if they contain relatively high flashpoint materials such as diesel.The first part of this paper describes the patterns of damage observed in buildings in the industrial estates around Buncefield. Methods for assessing the degree of external and internal damage are presented.The second part of the paper deals with failure modes and ignition of various types of liquid storage tank during vapour cloud explosions. Again, the Buncefield data provides excellent examples that illustrate the importance of tank design, fill level, location relative to the cloud, etc.     

Comparison of gut morphology and gut microflora of seven species of mud shrimp (Crustacea: Decapoda: Thalassinidea)

The gut morphology is described for seven species of Thalassinidea; Callianassasubterranea (Montagu), Jaxea nocturna Nardo, Axius stirhynchus Leach, Calocaris macandreae Bell, Upogebia pusilla (Petagna), U. deltaura (Leach) and U. stellata (Montagu). Differences were observed in the structure of the dorsal and lateral teeth of the gastric mill. Callianassa subterranea and A. stirhynchus had simple robust dorsal teeth and proportionally larger lateral teeth with flexible spines. The three upogebiids had complex dorsal teeth that were highly ridged and proportionally smaller lateral teeth with inflexible spines. The dorsal and lateral teeth of J. nocturna were intermediate in form. The dorsal tooth of Calocaris macandreae, although relatively simple in design, possessed accessory projections, or “wings”, on either side of the main structure. The lateral teeth were proportionally quite large, but lacked ridges and spines. The epithelia surfaces of the digestive gland, midgut and posterior diverticulum were similar for all seven species. Differences were observed in the morphology of the hindgut. The hindgut lining was completely smooth for the three upogebiid species. The other thalassinidean species had four distinct rows of cuticular projections situated on top of the ridges formed by the longitudinal convolutions of the hindgut. The arrangement of these projections varied between species. A gut flora was observed for six of the seven species, the exception being C. macandreae. The differences observed in the structure of the gut are discussed in relation to feeding and thalassinidean phylogeny. Received: 3 July 1998 / Accepted: 8 October 1998     

Retaining natural vegetation to safeguard biodiversity and humanity

Global efforts to deliver internationally agreed goals to reduce carbon emissions, halt biodiversity loss, and retain essential ecosystem services have been poorly integrated. These goals rely in part on preserving natural (e.g., native, largely unmodified) and seminatural (e.g., low intensity or sustainable human use) forests, woodlands, and grasslands. To show how to unify these goals, we empirically derived spatially explicit, quantitative, area-based targets for the retention of natural and seminatural (e.g., native) terrestrial vegetation worldwide. We used a 250-m-resolution map of natural and seminatural vegetation cover and, from this, selected areas identified under different international agreements as being important for achieving global biodiversity, carbon, soil, and water targets. At least 67 million km² of Earth's terrestrial vegetation (∼79% of the area of vegetation remaining) required retention to contribute to biodiversity, climate, soil, and freshwater conservation objectives under 4 United Nations’ resolutions. This equates to retaining natural and seminatural vegetation across at least 50% of the total terrestrial (excluding Antarctica) surface of Earth. Retention efforts could contribute to multiple goals simultaneously, especially where natural and seminatural vegetation can be managed to achieve cobenefits for biodiversity, carbon storage, and ecosystem service provision. Such management can and should co-occur and be driven by people who live in and rely on places where natural and sustainably managed vegetation remains in situ and must be complemented by restoration and appropriate management of more human-modified environments if global goals are to be realized.