Pollution,habitat loss,fishing, and climate change as critical threats to penguins

Cumulative human impacts across the world's oceans are considerable. We therefore examined a single model taxonomic group, the penguins (Spheniscidae), to explore how marine species and communities might be at risk of decline or extinction in the southern hemisphere. We sought to determine the most important threats to penguins and to suggest means to mitigate these threats. Our review has relevance to other taxonomic groups in the southern hemisphere and in northern latitudes, where human impacts are greater. Our review was based on an expert assessment and literature review of all 18 penguin species; 49 scientists contributed to the process. For each penguin species, we considered their range and distribution, population trends, and main anthropogenic threats over the past approximately 250 years. These threats were harvesting adults for oil, skin, and feathers and as bait for crab and rock lobster fisheries; harvesting of eggs; terrestrial habitat degradation; marine pollution; fisheries bycatch and resource competition; environmental variability and climate change; and toxic algal poisoning and disease. Habitat loss, pollution, and fishing, all factors humans can readily mitigate, remain the primary threats for penguin species. Their future resilience to further climate change impacts will almost certainly depend on addressing current threats to existing habitat degradation on land and at sea. We suggest protection of breeding habitat, linked to the designation of appropriately scaled marine reserves, including in the High Seas, will be critical for the future conservation of penguins. However, large‐scale conservation zones are not always practical or politically feasible and other ecosystem‐based management methods that include spatial zoning, bycatch mitigation, and robust harvest control must be developed to maintain marine biodiversity and ensure that ecosystem functioning is maintained across a variety of scales. Contaminación, Pérdida de Hábitat, Pesca y Cambio Climático como Amenazas Críticas para los Pingüinos     

The use of agricultural substrates to improve methane yield in anaerobic co-digestion with pig slurry: Effect of substrate type and inclusion level

Anaerobic co-digestion of pig slurry with four agricultural substrates (tomato, pepper, persimmon and peach) was investigated. Each agricultural substrate was tested in co-digestion with pig slurry at four inclusion levels: 0%, 15%, 30% and 50%. Inclusion levels consisted in the replacement of the volatile solids (VS) from the pig slurry with the VS from the agricultural substrate. The effect of substrate type and inclusion level on the biochemical methane potential (BMP) was evaluated in a batch assay performed at 35 °C for 100 days. Agricultural substrate’s chemical composition was also analyzed and related with BMP. Additionally, Bacteria and Archaea domains together with the four main methanogenic archaeal orders were quantified using quantitative real-time TaqMan polymerase chain reaction (qPCR) at the end of the experiment to determine the influence of agricultural substrate on sludge’s microbial composition. Results showed that vegetable substrates (pepper and tomato) had higher lipid and protein content and lower carbohydrates than fruit substrates (persimmon and peach). Among substrates, vegetable substrates showed higher BMP than fruit substrates. Higher BMP values were obtained with increasing addition of agricultural substrate. The replacement of 50% of VS from pig slurry by tomato and pepper increased BMP in 41% and 44%, respectively compared with pig slurry only. Lower increments in BMP were achieved with lower inclusion levels. Results from qPCR showed that total bacteria and total archaea gene concentrations were similar in all combinations tested. Methanomicrobiales gene concentrations dominated over the rest of individual archaeal orders.     

Copper-algae interactions: Inheritance or adaptation?

This study evaluated the responses of wild, adult plants of Enteromorpha compressa, and their progeny, to various copper concentrations. Experiments were designed to test the hypotheses that: 1) individuals of E. compressa from Caleta Palito, a copper-enriched coastal locality, tolerate higher copper concentrations than those from a place with no history of copper pollution and 2) such copper tolerance is under genetic control and therefore, was an inherited character. Our results indicate that algae which inhabit a copper-enriched environment tolerate higher concentrations of copper than those from waters with low copper concentrations. On the other hand, our results suggest that generalizations regarding heritability of the tolerance to copper do not apply to the Chilean E. compressa, as no differences in growth or rhizoid production were found between the progeny from Caleta Palito and Caleta Zenteno. These findings are an indication that heritability and adaptation may represent alternative strategies used by different populations of the same algal species to tolerate copper.     

Multivariate analysis of the bentho-demersal ichthyofauna along soft bottoms of the Eastern Atlantic: comparison between unvegetated substrates,seagrass meadows and sandy bottoms beneath sea-cage fish farms

By means of multivariate techniques, we studied: (1) the differences in the structure of bentho-demersal, non-cryptic, fish assemblages associated with unvegetated sandy substrates, vegetated meadows constituted by the seagrass Cymodocea nodosa and the bottoms under the influence of sea-cage fish farms; as well as (2) the persistence of these patterns with regard to different scales of spatial variability, across three islands of the Canarian Archipelago (Central East Atlantic). Our sampling strategy (involving three islands, with five locations per island, and two sites within each location) detected significant changes in the composition and structure of the fish assemblages between the three habitats. Fish assemblages associated with the unvegetated and vegetated bottoms were similar among the surveyed islands. In contrast, we observed a significant inter-island variability in the fish populations associated with the sea-cage fish farms. The presence of the sea-cage fish farms increased the overall fish abundance (184.8±49.8 ind 100 m⁻²) as compared to both the vegetated (38.8±9.7 ind 100 m⁻²) and unvegetated habitats (1.1±0.4 ind 100 m⁻²). Differences within and between the habitats were found to be associated with the relative abundance of a few fish species. The most abundant species were Xyrichthys novacula in the unvegetated bottoms and Diplodus annularis, Spondyliosoma cantharus and Mullus surmuletus on the seagrass meadows. Finally, we recorded an increase in the abundance of Heteroconger longissimus, Trachinus draco and Pagellus acarne in the bottoms beneath the sea-cage fish farms. These species, in addition to a group of large benthic chondrichthyes, were responsible for the differences between islands in the composition and structure of the demersal ichthyofauna beneath the sea-cage fish farms.     

Males are attracted by their own courtship signals

Courting male fiddler crabs Uca terpsichores (1 cm carapace width) sometimes build mounds of sand called hoods at the entrances to their burrows. Males wave their single enlarged claws to attract females to their burrows for mating. It was shown previously that burrows with hoods are more attractive to females and that females visually orient to these structures. In this study, we test whether males also use their hoods to find their burrows. We first determined the maximum distance that males can see and find a burrow opening without a hood. Males were removed from their burrows and placed on the sand at a range of distances from a burrow opening. If they were more than about 8 cm (seven units of eye-height) away, they were unable find the burrow. In contrast, males that were burrow residents used a non-visual path map to return to their burrows from much greater distances. To determine if hoods help males find their burrows when there are errors in their path maps, we moved residents 1–49 cm on sliding platforms producing errors equal to the distances they were moved. Males with self-made hoods or hood models at their burrows relocated their burrows at significantly greater distances than did males with unadorned burrows. Hood builders also relocated their burrows faster. Hence, hoods have two functions: they attract females and they provide a visual cue that males use to find their burrows quickly and reliably when their path maps fail. An erratum to this article can be found at     

Measurements of personal exposure to nitrogen dioxide in four Mexican cities in 1996

Nitrogen dioxide is a ubiquitous pollutant in urban areas. Indoor NO2 concentrations are influenced by penetration of outdoor concentrations and by indoor sources. The objectives of this study were to evaluate personal exposure to NO2, taking into account human time-activity patterns in four Mexican cities. Passive filter badges were used for indoor, outdoor, and personal NO2 measurements over 48 hr and indoor workplace measurements over 16 hr. Volunteers completed a questionnaire on exposure factors and a time-activity diary during the sample period. An unpaired t test, an analysis of variance (ANOVA), and a linear regression were performed to compare differences among cities and mean personal NO2 concentrations involving housing characteristics, as well as to determine which variables predicted the personal NO2 concentration. Sampling periods were in April, May, and June 1996 in Mexico City, Guadalajara, Cuernavaca, and Monterrey. All 122 volunteers in the study were working adults, with a mean age of 34 (SD +/- 7.38); 64% were female, and the majority worked in public offices and universities. The highest NO2 concentrations were found in Mexico City (36 ppb for outdoor, 57 ppb for indoor, and 39 ppb for personal concentration) and the lowest in Monterrey (19 ppb for outdoor, 24 ppb for indoor, and 24 ppb for personal concentration). Significant differences in NO2 concentrations were found among the cities in different microenvironments. During the sampling period, volunteers spent 85% of their time indoors. The highest personal NO2 concentration was found when volunteers kept their windows closed (p = 0.03). In the regression model adjusted by city and gender, the best predictors of personal NO2 concentration were outdoor levels and time spent outdoors (R2 = 0.68). These findings suggest that outdoor NO2 concentrations were an important influence on the personal exposure to NO2, due to the specific characteristics and personal behavior of the people in these Mexican cities.     

Ecosystem-based adaptation to climate change: what role for policy-makers, society and scientists?

In developing countries where economies and livelihoods depend largely on ecosystem services, policies for adaptation to climate change should take into account the role of these services in increasing the resilience of society. This ecosystem-based approach to adaptation was the focus of an international workshop on “Adaptation to Climate Change: the role of Ecosystem Services” held in November 2008 in Costa Rica. This article presents the key messages from the workshop.     

Linking edge effects and patch size effects: Importance of matrix nest predators

The edge effect is usually considered to be the proximate cause of area sensitivity in forest birds. We tested if birds nesting in large patches are less vulnerable to the edge effect using a simple model that assumes an increase in patch size reduces the probability of a matrix predator moving to the core areas of forest and that larger perimeter/area ratios result in a higher number of matrix predators per unit of area. The probability of a nest being successful decreased asymptotically with an increase in either the patch penetration distance of predators or predator density, but those effects were reduced when patch size was increased. Large patches have a lower probability of being affected by an Allee effect and they can function as sink habitats only if penetration distance and predator density are largely increased. However, the transition from an Allee effect to a sink condition occurs with a small increase in penetration distance and predator density. Since birds nesting in large patches are less vulnerable to an increase in matrix predator populations, persistence of bird populations may be possible by increasing the size of habitat patches that can act as source populations.     

Rendering Bio-inert Low-Density Polyethylene Amenable for Biodegradation via Fast High Throughput Reactive Extrusion Assisted Oxidation

Journal of Polymers and the Environment - An energy-efficient high throughput pre-treatment of low-density polyethylene (LDPE) using a fast, reactive extrusion (REX) assisted oxidation technique...