Habitat use by dusky dolphin in patagonia: how predictable is their location?

Off Patagonian coasts, Argentina, the dusky dolphin is one of the most common small cetaceans. This species is the aim of newly developed watching activities during summer in Golfo Nuevo. However, the real occurrence and movement pattern are unknown. The objectives of this work were to investigate the predictability of dusky dolphin distribution, group structure and behaviour in the western portion of Golfo Nuevo, with respect to environmental features (bottom depth, bottom slope, distance from shore and substrate). Random transects in the bay were searched by small boat during the summer and autumn of 2001–2004. When a group of dolphins was sighted, estimates of group size, composition (mothers with calves, adults and juveniles only, and mixed groups) and the predominant activity (feeding, travelling, socialising, resting and milling) were recorded and thereafter at 2 min intervals. A grid of 1.5 × 1.5 km was constructed and each cell was characterised by environmental features, Area Use Index (percent of total annual search effort) and Activity Index (predominant behaviour of groups observed in that cell). Mothers with calves and smaller groups and resting behaviour occurred in shallowest waters supporting the idea/hypothesis that movement to shallower water is related to increased safety for individuals. Travelling occurred in the deepest areas with other behaviours observed in intermediate depths. Dolphin distribution within the bay differed significantly between years, but this was not related to any of the factors analysed in this study. Although there was considerable variation between years, in general, dolphins were found in deeper waters further from shore (except for mother–calf groups) and over areas with steeper seafloor gradient. The high variability in the distribution of the animals does not allow for the generation of a simple, area-specific management plan.     

Heavy metals removal from electroplating wastewater by aminopropyl-Si MCM-41

The potential of removing nickel and copper from industrial electroplating wastewaters by using mesoporous materials with MCM-41 type structure functionalised with different ratios of aminopropyl groups, namely Na50, Na25 and Na5, were evaluated. The synthesised solids sorbents obtained were characterised by X-ray diffraction, elemental chemical analysis and IR spectroscopy. In preliminary experiments, studies were carried out to determine the optimal experimental conditions for the retention of heavy ions. Effects of concentration, optimal pH, interference with humic substances and other metals were studied for Na5, which showed the best capacity of absorption determined by the corresponding isotherm. This material has a greater selectivity against sodium, indicating that ionic strength does not affect the extraction. Results of an application of this material to remove nickel and copper in synthetic and real industrial wastewater samples from an electrochemical industry area are shown with successful results. The lowest level of nickel and copper were observed when Na5 was used. This observation suggests that reactive aminopropyl-Si MCM-41 and similar materials may be a promising and provide for alternative environmental technologies in the future.     

Establishing politically feasible water markets: a multi-criteria approach

A multiple criteria decision-making (MCDM) model to simulate the establishment of water markets is developed. The environment is an irrigated area governed by a non-profit agency, which is responsible for water production, allocation, and pricing. There is a traditional situation of historical rights, average-cost pricing for water allocation, large quantities of water used, and inefficiency. A market-oriented policy could be implemented by accounting for ecological and political objectives such as saving groundwater and safeguarding historical rights while promoting economic efficiency. In this paper, a problem is solved by compromise programming, a multi-criteria technique based on the principles of Simonian logic. The model is theoretically developed and applied to the Lorca region in Spain near the Mediterranean Sea.     

Race, Ethnicity and Disasters in the United States: A Review of the Literature

In this paper we synthesise past disaster research that addresses issues of race and ethnicity in the United States. Using an eight-stage typology to organise the findings, this literature review presents the results from a wide range of studies. The synthesis shows how various racial and ethnic groups perceive natural hazard risks and respond to warnings, how groups may be differentially affected, both physically and psychologically, and how disaster effects vary by race and ethnicity during the periods of emergency response, recovery and reconstruction. We show that studies have important findings, many illustrating that racial and ethnic communities in the US are more vulnerable to natural disasters, due to factors such as language, housing patterns, building construction, community isolation and cultural insensitivities. By presenting these studies together, we are able to witness patterns of racial and ethnic inequalities that may be more difficult to see or interpret in individual studies that take place in one specific time and place. We conclude the review with policy and research recommendations.     

Reproductive biology of <Emphasis Type="Italic">Cosmasterias lurida</Emphasis> (Echinodermata: Asteroidea) an anthropogenically influenced substratum from Golfo Nuevo,Northern Patagonia (Argentina)

The starfish Cosmasterias lurida was sampled from the pier piles of Almirante Storni in the Golfo Nuevo, northern Patagonia, from November 2001 to November 2003. In this anthropogenically modified site there is an unusually abundant food supply of mussels and large aggregations of starfishes. The reproductive cycle was studied by organ indices and histological examination of gonads. The highest gonad index (GI) values were found in the summer (February–March), followed by a drop in GI values, indicating spawning. Histological analyses indicated that gametogenesis takes place from June to January, sexual maturity occurred during the summer and spawning occurred in April. The GI and pyloric caeca index (PCI) tended to have an inverse relationship, but this was only statistically significant in males. However, biochemical analyses of the starfish indicated no transfer of nutrients between pyloric caeca and gonads in either sex. In fact, simultaneous accumulation of carbohydrates was found in the pyloric caeca and gonads of both sexes.     

Substrate use and temporal pattern of recruitment in juvenile fishes of the Mediterranean littoral

The microhabitat use and seasonality of the juveniles of 24 littoral species in the north-west Mediterranean Sea were studied between March 1993 and March 1994. Labrids species recruit during summer months, from July to September, whereas sparids recruit at different times of the year. Canonical correspondence analysis revealed that the species recruit in well-defined habitats. Sparid species recruit primarily in the shallowest zone (0 to 2 m), and most of them prefer varied bottoms (sand, gravel or small blocks). Some species of the genus Diplodus have similar habitat requirements, but show a clear seasonal segregation, with each species occupying successively the same zones at a different time of the year. Labrid species show a high degree of seasonal and spatial co-occurrence, and are normally found on rocky substrates with high algal cover. Two species (Mullus surmuletus and Symphodus cinereus) recruit mainly in Posidonia oceanica beds, while other species (Serranus cabrilla, Coris julis, Symphodus ocellatus, S. rostratus), are abundant in both seagrass beds and on rocky substrates.     

Effect of prey densities on cannibalism in Cape hake (Merluccius capensis) off Namibia

The preference of large (>60 cm total length) Cape hake (Merluccius capensis Castelnau, 1861) for small conspecifics under natural conditions was analyzed off southern Namibia (S.E. Atlantic) between 1983 and 1989. The results indicate that cannibalism is not related to the density of the small conspecifics nor to the density of alternative prey, but rather that large hake have a dietary preference for small conspecifics. The main consequence of such cannibalism is a lack of density-dependent regulation of the M. capensis population.     

Phenotypic plasticity in a mutualistic association between the sponge Haliclona caerulea and the calcareous macroalga Jania adherens induced by transplanting experiments. I: morphological responses of the sponge

The mutualistic association between the sponge Haliclona caerulea and the calcareous red macroalga Jania adherens is conspicuous on shallow rocky regions of Mazatlán Bay (eastern tropical Pacific, Mexico). Transplanting experiments were carried out to examine the morphological responses of the association to an environmental depth gradient. Simultaneously, we conducted caging experiments to examine the effects of predation (mainly by angelfishes) on association morphology. For this, we transplanted specimens of the association from a control area at 3 m depth to depths of 1 and 5 m, and measured the morphological responses in the association (macro- and microstructure) from the three sites before and after 103 days. The association had the capacity to adjust both macro and micromorphologically, and both external morphology and body structure changed significantly with depth. The specimens grown at 1 m developed a larger surface area of attachment, higher organic density and higher inorganic content than the control specimens at 3 m, and the organisms grown at 5 m depth. We also detected significant differences in the aquiferous system of the sponge, which developed smaller and more numerous oscula at 1 m than at 5 m depth. These differences seem to be consistent with the wave movement as one of the main regulatory factors of the morphology of the association. However, the spicules from H. caerulea were most slender in shallow water, which is not consistent with increasing robustness in the face of greater wave force. The algal skeleton supplied up to 27% of the total inorganic structure of the association; thus, algal contribution significantly reduces the energy costs of spicule production, specifically under high wave exposure, when H. caerulea requires structural reinforcement relative to organic content. The contribution of the sponge to the association (as ratio Si to CaCO₃) increased significantly from 3 to 5 m (12% in the uncaged specimens and 22% in the caged specimens), showing that the mutualistic relationship decreases with depth. The production of sponge branches in caged individuals was the most notable difference from uncaged morphs, which could suggest the effect of predators like angelfishes. However, branches could also be a response to the reduction in water movement and irradiance inside the cages. Sponges are known to show morphological acclimation in response to habitat variation, but this is the first study to show it in a sponge living in association with a macroalga.     

Atmospheric dynamics and ozone cycles related to nitrogen deposition in the western Mediterranean

Recent results from EU-sponsored projects have shed new light on the workings of the atmosphere in the Mediterranean Basin, where a large airmass becomes trapped and nearly stagnant over the sea during the summer. This work reviews the developments which have led to our present understanding of air pollution dynamics and associated meteorological processes in this region. In summer, the sea breezes combine with upslope winds to create recirculations along the coasts and within the western Mediterranean basin, with residence times in the order of days. Under strong insolation these recirculations become "large natural photo-chemical reactors" where most of the NOx emissions and other precursors are transformed into oxidants, acidic compounds, aerosols and ozone, which can exceed European Union directives for several months of the year. The objective of this paper is to evaluate available experimental evidence and complementary modelling results to help in the interpretation of observed ozone cycles and to anticipate possible scenarios for anthropogenic nitrogen deposition in the region.