Ultrafiltration of wastewater from isolated soy protein production: A comparison of three UF membranes

The proteins of the wastewater from ISP production are small molecules (8–50 kDa) that were not removed during the production process; their recovery would result in large productive and financial advantages. Ultrafiltration appears as good alternative in wastewater treatment; one of the biggest limitations is the decrease in permeate flux. The performance of three UF membranes (5, 20 and 50 kDa) treating the wastewater from ISP production was evaluated. The use of these membranes is very promising regarding organic load and protein content reduction. The 5-kDa membrane presented the best results: the lowest permeate flux reduction, the most elevated retention percentages (34% of COD, 52% of protein, 21% of TS and 86% of TSS) and the wastewater with the best final quality.     

Surveillance of Enteric Viruses and Thermotolerant Coliforms in Surface Water and Bivalves from a Mangrove Estuary in Southeastern Brazil

This study was conducted to evaluate the microbiological quality of a mangrove estuary in the Vitória Bay region, Espírito Santo, Brazil. We analyzed the presence and concentration of enteric viruses and thermotolerant coliforms in water, mussels (Mytella charruana and Mytella guyanensis), and oysters (Crassostrea rhizophorae), collected over a 13-month period. Human adenovirus, rotavirus A (RVA), and norovirus genogroup II were analyzed by quantitative PCR. The highest viral load was found in RVA-positive samples with a concentration of 3.0 × 10⁴ genome copies (GC) L⁻¹ in water samples and 1.3 × 10⁵ GC g⁻¹ in bivalves. RVA was the most prevalent virus in all matrices. Thermotolerant coliforms were quantified as colony-forming units (CFU) by the membrane filtration method. The concentration of these bacteria in water was in accordance with the Brazilian standard for recreational waters (< 250 CFU 100 mL⁻¹) during most of the monitoring period (12 out of 13 months). However, thermotolerant coliform concentrations of 3.0, 3.1, and 2.6 log CFU 100 g⁻¹ were detected in M. charruana, M. guyanensis, and C. rhizophorae, respectively. The presence of human-specific viruses in water and bivalves reflects the strong anthropogenic impact on the mangrove and serves as an early warning of waterborne and foodborne disease outbreaks resulting from the consumption of shellfish and the practice of water recreational activities in the region.

     

Sexual harassment and female gregariousness in the South American sea lion, Otaria flavescens

Most colonial pinnipeds form extreme clusters of breeding females that cannot be entirely explained by the distribution of sites for reproduction. Avoidance of male harassment has been postulated as an important determinant of reproductive aggregation in this group of mammals. Female gregariousness can reduce harassment by resident males by two mechanisms; directly by the 'dilution effect' or indirectly because resident males that defend large female groups are less harassing. In order to investigate the relationship between male harassment and female gregariousness in relation to the size of breeding groups, we analysed the behaviour of dominant males and their females in a breeding colony of Otaria flavescens. Females in large breeding groups received less harassment by resident males due to dilution effects and because males that defended a large group interacted less frequently with females than males with small groups.     

Scale-dependent analysis of an otter–crustacean system in Argentinean Patagonia

The Southern river otter or ‘huillin’, Lontra provocax, is an endangered species endemic of the Andean Patagonian region of Argentina and Chile. It feeds almost exclusively on the genera of macro-crustacea: Aegla and Sammastacus. The aim of this study was to analyse the role of food availability on the huillin’s distribution using a scale-dependent analysis of crustacean and otter distributions. We compared the distributions of otters and macro-crustaceans along a north–south regional gradient, between river basins of northern Patagonia, in an altitudinal gradient within a river basin, and between habitat types within a lake. We investigated the distribution of otters by sign surveys along lake shores, river banks and marine coasts, and of crustaceans using surveys in the water, undigested remains in mink (Mustela vison) scats, presence of external skeletons at the waterside and through interviews with local people. Our results show that there were heterogeneities in the distributions of macro-crustaceans at four scales and these were generally reflected in the distributions of freshwater otters. We conclude that the main factor limiting the distributions of L. provocax in freshwater environments is the availability of macro-crustaceans. This paper shows how scale-dependent type analyses of population distribution serves as a method for identifying key environmental factors for species for which the use of long-term demographies is unfeasible.     

A critical review of the precautionary approach of the IUCN impact classification for non-native taxa

The International Union for the Conservation of Nature (IUCN) proposes the use of the Environmental Impact Classification for Alien Taxa to standardize the classification of introduced species (IS) based on their environmental impact. The IUCN invoked the precautionary principle (PP) via 2 rules: the impact assigned to a taxon must be the maximum recorded impact across different impact assessments, and when the main driver of environmental damage is unclear, it must be assumed to be caused by the IS. The validity of PP is conditioned on the degree of emergency that warrants urgent decisions and on the scientific evidence demonstrating the advantages of applying a preventive measure. The application of an impact classification system does not arise in the context of an emergency that requires management; it occurs before the decision-making phase. Thus, PP should not be used in early steps of the risk analysis process. The IUCN also did not provide enough scientific basis to justify the use of PP. Instead, the PP rules appear to be rooted primarily in the ethical value system underlying conservation science. Conservationists assign intrinsic value to native species by virtue of their roles and relationships within ecological and evolutionary systems and processes; thus, individuals introduced in new environments not only cease to have value because they are no longer part of that natural diversity and lack those links with the rest of the ecosystem, but they become a threat to what conservationists value most. The consequence of this belief is that all introduced taxa will have an impact at some level, suggesting that values justify the PP rules.     

Analysis of environmental correlates of sexual segregation in northern elephant seals using species distribution models

Elephant seals are among the most sexually dimorphic and polygynous species of all mammals. Their foraging grounds occupy a wide area of the world oceans, where they show spatial segregation between males and females. The objective of this paper was to correlate female and male foraging distributions of Mirounga angustirostris with main climatic variables at a biogeographical scale. We used website and bibliographical sources to obtain information on adult elephant seal distribution and environmental predictors (surface and bottom sea temperatures, productivity and bathymetry) and three species distribution models [maximum entropy model, environmental niche factor analysis and based on climatic envelopes (BIOCLIM)] to predict the habitat suitability of ocean regions. BIOCLIM provided the best fit. Sea surface and bottom temperatures were the variables with the highest explanatory power for females, while bathymetry was for males. Predictive maps suggest that low temperatures constrain female, but not male, distribution at high latitudes. We suggest that large size increases foraging efficiency of males because, among other benefits, it augments thermal insulation, improving the use of cold, rich sectors of the ocean. Different thermoregulatory abilities between sexes due to size dimorphism should be a complementary explanation of sexual segregation in elephant seals.