Spatio-temporal variations of biomass and abundance in bathyal non-crustacean megafauna in the Catalan Sea (North-western Mediterranean)

The spatio-temporal variations in diversity, biomass and abundance of bathyal invertebrates (excluding decapod crustaceans, which have been analysed elsewhere) from the North-western Mediterranean margin are described. The upper canyon (∼450 m), middle slope (∼650 m) and lower slope (∼1,200 m) habitats were investigated throughout the year. The first two sites are visited daily by a specialised commercial fisheries’ fleet, while the deeper site has not been impacted by fishing activities. A total of 140 species from 12 phyla were collected from the 3 study areas. Of these, the Mollusca, Echinodermata, Polychaeta and Cnidaria were the most speciose groups. The patterns of species diversity (H′) and evenness (E) were similar in time and space. The upper canyon and middle-slope sites were dominated by echinoderms and molluscs, while the lower-slope site was dominated by cnidarians and sponges. Multifactorial ANOVA showed significant spatio-temporal differences in the biomass and/or abundance only in echinoderms, molluscs, cnidarians and polychaetes. The faunal differences observed were explained by habitat type, but not by season. The role of submarine canyons and commercial fishing on shaping the diversity and biomass of bathyal Mediterranean invertebrates is discussed. Luis Dantart: Deceased March 2005     

Spatial and temporal variability of phytoplankton biomass,primary production and community structure in the Pontevedra Ria (NW Iberian Peninsula): oceanographic periods and possible response to environmental changes

The spatial distribution of phytoplankton assemblages, chlorophyll, primary production and physical and chemical parameters were studied in the Pontevedra Ria in Galicia (NW Iberian Peninsula) from October 1997 to October 1998. In addition to the usual oceanographic periods described for the Galician Coast, two other periods were observed: a Prebloom or winter bloom, occurring during calm, sunny days in winter and a Continental period, related to the allochthonous intrusion of low salinity water from the Miño River in late spring. The phytoplankton biomass and production in both periods reached values of up to 145 mgChl-a m^?2 and 3.6 gC m^?2 day^?1, respectively, which were similar to those found in summer upwelling blooms. Throughout the year, the phytoplankton biomass and primary production gradients along the ria’s axis were highly dependent on the balance between upwelling and runoff. When the latter prevailed, increased values were measured toward the inner ria, while the opposite pattern was observed during summer upwelling blooms. According to projections derived from climate models and the analysis of wind patterns, temperature and precipitation trends in the area, a drop in the productivity of the ria would be expected as a result of reduced upwelling intensity in summer and decreasing rainfall in spring. In any case the estuarine part of the ria would be the most seriously affected.     

Controlling risks of P water pollution by sorption on soils,pyritic material,granitic material,and different by-products: effects of pH and incubation time

Environmental Science and Pollution Research - Batch experiments were used to test P sorbent potential of soil samples, pyritic and granitic materials, mussel shell, mussel shell ash, sawdust, and...     

High overlap between traditional ecological knowledge and forest conservation found in the Bolivian Amazon

It has been suggested that traditional ecological knowledge (TEK) may play a key role in forest conservation. However, empirical studies assessing to what extent TEK is associated with forest conservation compared with other variables are rare. Furthermore, to our knowledge, the spatial overlap of TEK and forest conservation has not been evaluated at fine scales. In this paper, we address both issues through a case study with Tsimane’ Amerindians in the Bolivian Amazon. We sampled 624 households across 59 villages to estimate TEK and used remote sensing data to assess forest conservation. We ran statistical and spatial analyses to evaluate whether TEK was associated and spatially overlapped with forest conservation at the village level. We find that Tsimane’ TEK is significantly and positively associated with forest conservation although acculturation variables bear stronger and negative associations with forest conservation. We also find a very significant spatial overlap between levels of Tsimane’ TEK and forest conservation. We discuss the potential reasons underpinning our results, which provide insights that may be useful for informing policies in the realms of development, conservation, and climate. We posit that the protection of indigenous cultural systems is vital and urgent to create more effective policies in such realms.     

Life cycle assessment and sustainable engineering in the context of near net shape grown components: striving towards a sustainable way of future production

Technical product harvesting (TEPHA) is a newly developing interdisciplinary approach in which bio-based production is investigated from a technical and ecological perspective. Society‘s demand for ecologically produced and sustainably operable goods is a key driver for the substitution of conventional materials like metals or plastics through bio-based alternatives. Technical product harvesting of near net shape grown components describes the use of suitable biomass for the production of technical products through influencing the natural shape of plants during their growth period. The use of natural materials may show positive effects on the amount of non-renewable resource consumption. This also increases the product recyclability at the end of its life cycle. Furthermore, through the near net shape growth of biomass, production steps can be reduced. As a consequence such approaches may save energy and the needed resources like crude oil, coal or gas. The derived near net shape grown components are not only considered beneficial from an environmental point of view. They can also have mechanical advantages through an intrinsic topology optimization in contrast to common natural materials, which are influenced in their shape after harvesting. In order to prove these benefits a comprehensive, interdisciplinary scientific strategy is needed. Here, both mechanical investigations and life cycle assessment as a method of environmental evaluation are used.     

Multivariate Statistical Analysis of Meteorological and Air Pollution Data in the ‘Campo De Gibraltar’ Region, Spain

A complete statistical analysis of meteorological and air pollution data was carried out in the ‘Campo de Gibraltar’ region (in the South of Spain) from 1999 to 2002. This is a heavy industrialized area where, up to date, very few air pollution studies have been made. The main objectives of the study presented here have been the characterization of the meteorological and (gaseous and particulate) air pollution conditions in the area, and the relations between them. Multivariate statistical techniques, such as Principal Component Analysis (PCA), have been applied to the data. The results show that air quality in the area is highly dependent on meteorological conditions such as wind persistence and direction, dispersion capability of the atmosphere, and humidity content. On average, sulphur dioxide and nitrogen oxide air pollution, mainly caused by fuel-oil combustion and traffic, respectively, is not very high. However, an important number of exceedences of the limits established by the EU Directive 1999 for PM10 (particulate matter with a diameter less than 10 μm) have been observed in some points of the area. A significant percentage of these exceedences (about 22% on average) are likely caused by African dust intrusions, which usually take place from May to August. From gaseous and particulate air correlations, it seems that anthropogenic activities contribute with about 19% on average.     

Regeneration of Nothofagus pumilio [Poepp. et Endl.] Krasser forests after five years of seed tree cutting

Nothofagus pumilio [Poepp. et Endl.] Krasser is a deciduous tree species that grows in Chile and adjacent Argentina between 36 and 56 degrees S, often forming the Andean tree line. Silvicultural systems proposed for this species integrate both regeneration and intermediate level operations in an orderly process for managing forest stands. The seed-tree method of regeneration has been used to manage even-aged stands of this species. This paper investigates the effect of seed tree cuttings on the regeneration of Nothofagus pumilio [Poepp. et Endl.] Krasser forest located in the Magallanes region (Chile). The studied forest was managed on an even-aged basis using a seed tree silvicultural system for regeneration with an intensity of cutting of 65-70% of the basal area and a minimum of 15 dominant lenga trees per hectare retained. A regeneration inventory sampling was used to quantify regeneration attributes in the study area. Regeneration was found to be significantly affected by the seed tree cuttings. In fact, the number of established individuals rose from 0.39 to 26.7 plants m(-2) pre-harvest to 9.2-21.5 plants m(-2) post-harvest, depending on the particular development stage. Total regeneration ranged from 9.5 to 48.2 plants m(-2). The number of plants established over the period 1992-1997 was related to the residual basal area, coverage and number of trees. However, mean tree height was not significantly related to any regeneration variable. Significant variables were used to establish a regeneration prediction model using single and multiple linear equations (R2<0.418). Consequently, the seed tree method of regeneration can be considered feasible for commercially valuable lenga forests, although this method, in its strictest application, will create many large, irregularly shaped, even-aged groups.     

Spatial and temporal occurrence of N-nitrosamines in seven drinking water supply systems

The spatiotemporal presence of eight N-nitrosamines in the water of seven supply systems in Quebec considered to be susceptible to these emerging disinfection by-products was evaluated. This is the first study on the presence of N-nitrosamines in drinking water utilities in Quebec. Seven sampling campaigns were carried out at several sampling points in each of the systems over a period of 1 year. The results show that N-nitrosamines, primarily N-nitrosodimethylamine (NDMA), were not commonly detected in the water of the facilities under study (10 % of samples). The concentrations measured were lower than those reported in recent North American studies. None of the 195 samples taken exceeded the Ontario standard of 9 ng/L for NDMA (maximum value observed of 3.3 ng/L). N-nitrosomethylethylamine and N-nitrosopiperidine were detected once, with concentrations of 3.7 and 6.0 ng/L, respectively. Chloramination was identified as being the main risk factor regarding the presence of N-nitrosamines, but water quality and some operating parameters, in particular disinfectant residual, also seem to be related to their presence. NDMA concentrations at the end of the distribution systems were generally higher than water leaving the plant. No seasonal trends were observed for the formation of N-nitrosamines in the investigated supply systems. Finally, an association between the presence of N-nitrosamines and the levels of trihalomethanes and haloacetic acids was observed in some facilities.     

Optimizing booster chlorination in water distribution networks: a water quality index approach

The optimization of chlorine dosage and the number of booster locations is an important aspect of water quality management in distribution networks. Booster chlorination helps to maintain uniformity and adequacy of free residual chlorine concentration, essential for safeguarding against microbiological contamination. Higher chlorine dosages increase free residual chlorine concentration but generate harmful by-products, in addition to taste and odor complaints. It is possible to address these microbial, chemical, and aesthetic water quality issues through free residual chlorine concentration. Estimating a water quality index (WQI) based on regulatory chlorine thresholds for microbial, chemical, and aesthetics criteria can help engineers make intelligent decisions. An innovative scheme for maintaining adequate residual chlorine with optimal chlorine dosages and numbers of booster locations was established based on a proposed WQI. The City of Kelowna (BC, Canada) water distribution network served to demonstrate the application of the proposed scheme. Temporal free residual chlorine concentration predicted with EPANET software was used to estimate the WQI, later coupled with an optimization scheme. Preliminary temporal and spatial analyses identified critical zones (relatively poor water quality) in the distribution network. The model may also prove useful for small or rural communities where free residual chlorine is considered as the only water quality criterion.     

Seasonal changes in the diet of a critically endangered seabird and the importance of trawling discards

Pelagic seabirds obtain food from oceans where the availability of their prey changes rapidly both seasonally and spatially. Here, we investigated changes in the trophic habits of the critically endangered Balearic shearwater (Puffinus mauretanicus) through the breeding season and tested for dietary differences between sexes and age classes. We analysed δ¹⁵N and δ¹³C values in blood of adults during the pre-incubation, incubation and chick-rearing periods and of their chicks. Using a two-isotope mixing model, we estimated dietary contributions based on isotope values from potential prey species which included small pelagic species available naturally and demersal fish species available only from trawling discards. Balearic shearwaters showed clear isotopic and dietary variation through the breeding season. During pre-incubation, breeding adults appeared to exploit demersal fish, whereas during the incubation and chick-rearing period, they fed mainly on pelagic anchovies (Engraulis encrasicolus) and pilchards (Sardina pilchardus). Similarly, chicks were fed mainly with anchovies, a resource with a high energetic value. This variation in the dietary habits of adult shearwaters during the breeding season was probably related to both natural and fishery-induced seasonal changes in the availability of potential prey species within their main feeding grounds. However, changes in the nutritional requirements of the shearwaters could also play an important role. Indeed, diet differed between sexes during pre-incubation: females fed less on trawling discards and more on small pelagic fish than males. This sexual segregation in diet could be the consequence of higher nutritional requirements of females during this period. Our study reveals the differential importance of both trawling discards and small pelagic fish species for a pelagic seabird depending on the breeding period and illustrates the importance of considering the entire breeding season when making inferences about the importance of specific prey in seabird dietary studies.