Influences of winery–distillery waste compost stability and soil type on soil carbon dynamics in amended soils

The application of organic materials to replenish soil organic matter and improve soil structure and fertility has become a common agronomic practice. This research deals with the effects of soil amendment with winery and distillery waste composts on organic carbon (C) mineralisation in two arable soils. A sandy-loam and clay-loam soil were treated and incubated with a number organic materials obtained from the co-composting of different proportions of grape stalk, grape marc, exhausted grape marc and vinasse, with sewage sludge or animal manure. Moreover, the effect of compost stability on C mineralisation dynamics was studied by applying organic materials from different stages of the composting process. The results obtained showed that the addition of exogenous organic matter stimulated microbial growth, enhanced soil respiration and increased water-extractable C contents in both soils, particularly in the days immediately following amendment. The initial composition of the different organic materials used, especially for the mature samples, and the texture of the receiving soil did not influence significantly the C mineralisation final values, with around 11–20% of the added organic C being mineralised over the first 140 days. However, the contribution of organic amendment to the labile organic C pool, maximum rates of soil respiration, as well as the extent of initial disturbance of the soil microbiota were all found to be related to the degree of organic matter stability. Moreover, irrespective of the type and stability of the organic amendment, the mineralogical composition of the receiving soil was found to significantly influence its resilience in such systems.     

Evaluation of the variegated scallop Chlamys varia as a biomonitor of temporal trends of Cd, Cu, and Zn in the field

This study assesses the potential of the scallop Chlamys varia as a biomonitor of metal contamination in the field. Cd, Cu, and Zn concentrations were determined in the soft tissues and organs of individuals from the French Atlantic coast sampled over a 1 year period and covering a wide range of size. All metals were selectively distributed among the different body compartments considered, and their concentrations were influenced by the size of the specimens or the sampling-season. The present work shows the importance of considering the body compartment, the sampling period and the size in studies aiming at using this scallop as a biomonitor species. Among tissues, the digestive gland and kidneys exhibited the highest metal concentrations whatever the season or the size. The digestive gland contained 65 and 48% of the whole Cd and Cu body burdens, respectively, and kidneys accounted for 85% of the Zn load. Those tissues are therefore particularly recommended for use in biomonitoring programs.     

Knowledge and beliefs regarding agricultural pesticides in rural Guatemala

Throughout Central America, the United States Agency for International Development (USAID), and the Zamorano Pan-American Agricultural School support a Safe Pesticide Use program. In 1993, a study of results was carried out among farmers and housewives in eastern Guatemala. Aspects of the methodology included: (1) participation of extension workers in all aspects of the study; (2) small, region-focused samples (eight cells, 30 interviews per cell); (3) comparison to control groups of untrained farmers and housewives; (4) a traditional questionnaire for studying acquisition of specific knowledge; and (5) a flexible instrument for building a cognitive map of knowledge and beliefs regarding pesticides. The cognitive map is a step toward applying modern psychocultural scaling, an approach already well developed for medicine and public health, to environmental problems. Positive results detected include progress at learning the meaning of colors on containers that denote toxicity and where to store pesticides. Pesticide application problems detected were mention by farmers of highly toxic, restricted pesticides as appropriate for most pest problems and of insecticides as the correct solution to fungus problems, and the widespread belief that correct pesticide dosage depends on number of pests seen rather than on land or foliage surface. Health-related problems detected were admission by a vast majority of housewives that they apply highly toxic pesticides to combat children's head-lice; low awareness that pesticides cause health problems more serious than nausea, dizziness, and headaches; and a common belief that lemonade and coffee are effective medicines for pesticide poisoning.     

Trace element (Cd, Cu, Hg, Se, Zn) accumulation and tissue distribution in loggerhead turtles (Caretta caretta) from the Western Mediterranean Sea (southern Italy)

Cadmium (Cd), copper (Cu), mercury (Hg), selenium (Se) and zinc (Zn) were determined in the liver, kidney and muscle of 29 loggerhead turtles, Caretta caretta, from the South Tyrrhenian Sea (Western Mediterranean). No significant differences (p>0.05) were detected between males and females. Trace element concentrations were not influenced by the size of the specimen except Se in the liver, which was negatively correlated with the curved carapace length (p<0.001). Muscles generally displayed the lowest trace element burdens, with the exception of Zn which contained concentrations as high as 176 microgg-1dwt. Kidneys displayed the highest Cd and Se mean concentrations (57.2+/-34.6 and 15.5+/-9.1 microgg-1dwt, respectively), while liver exhibited the highest Cu and Hg levels (37.3+/-8.7 and 1.1+/-1.7 microgg-1dwt, respectively). Whichever tissue is considered, the toxic elements had elevated coefficients of variation (i.e. from 60% to 177%) compared to those of the essential ones (i.e. from 14% to 65%), which is a consequence of homeostatic processes for Cu, Se and Zn. Globally, the concentrations of Hg remained low in all the considered tissues, possibly the result of low trophic level in sea turtles. In contrast, the diet of loggerhead turtles would result in a significant exposure to Cd. Highly significant correlations between Cd and Cu and Zn in the liver and kidney suggest that efficient detoxification processes involving MT occur which prevent Cd toxicity in loggerhead turtles.     

Interannual patterns of variation in concentrations of trace elements in arms of Octopus vulgaris

Concentrations of essential (copper, iron, manganese, selenium, and zinc) and non-essential (arsenic, cadmium, mercury, and lead) trace elements were measured in arms of Octopus vulgaris. The cephalopods were sampled from commercial fishery landings at two sites on the Portuguese coast in spring 2002 and 2003. Mercury was determined using an Advanced Mercury Analyser Spectrophotometer (AMAS) and other trace elements were measured using inductively coupled plasma-atomic emission spectrometry (ICP-AES). Since high levels of arsenic were detected, identification of the forms present was carried out using high performance liquid chromatography (HPLC) followed by ICP-MS. Mean concentrations of trace elements analysed were in the following order: As > Zn > Fe > Cu > Cd > Pb > Se > Mn > Hg. The results of speciation of arsenic demonstrate that virtually all arsenic was in the arsenobetaine form, which is the less toxic form. The concentrations of several trace elements were generally high in samples from Viana in 2002. Cadmium concentrations were above the legal limit for human consumption in samples from Viana in 2002 and two of these animals also had lead concentrations that exceeded legal limits. Mercury appeared in all samples but levels were within legally defined safe limits. No relationship was detected between trace element concentrations and size or maturity of octopus.     

Correction to: Ecological restoration as a strategy for mitigating and adapting to climate change: lessons and challenges from Brazil

Mitigation and Adaptation Strategies for Global Change - The original version of the article unfortunately contained an error.     

Carbon conservation strategy for the management of pig slurry by composting: Initial study of the bulking agent influence

The intensification of the livestock production systems implies a potential environmental risk, associated with the great generation of animal wastes and slurries and their storage and management. Manure management is associated with considerable emissions of ammonia (NH₃) and greenhouse gases (GHG). However, the potential for GHG mitigation is highly dependent on the waste treatment strategy considered. This laboratory study aims to evaluate the influence of the type of bulking agent used on the potential reduction of the carbon dioxide (CO₂) emission, dealing with carbon (C) conservation when the solid fraction of pig (Sus scrofa domesticus) slurry is managed by composting. For this, a composting experiment in batch reactors was run with four mixtures elaborated using the solid fraction of pig slurry (SPS) and different materials (maize (Zea mays) stalks, barley (Hordeum vulgare L.) straw, cotton (Gossypium hirsutum) gin and garden prunings) as bulking agents. The potential C conservation in the mixtures was evaluated by determining the CO₂ emissions; the evolution of the mixtures, the thermal profile developed and the thermodynamics of the process were also studied. The mixtures elaborated with cotton gin and garden prunings showed the fastest temperature development, and also the highest CO₂ emissions. However, the use of maize stalks as bulking agent reduced CO₂ emissions due to its slow degradability: this could constitute a suitable strategy to promote C conservation during the management of pig slurry by composting.     

Ocean acidification and temperature rise: effects on calcification during early development of the cuttlefish Sepia officinalis

This study investigated the effects of seawater pH (i.e., 8.10, 7.85 and 7.60) and temperature (16 and 19 °C) on (a) the abiotic conditions in the fluid surrounding the embryo (viz. the perivitelline fluid), (b) growth, development and (c) cuttlebone calcification of embryonic and juvenile stages of the cephalopod Sepia officinalis. Egg swelling increased in response to acidification or warming, leading to an increase in egg surface while the interactive effects suggested a limited plasticity of the swelling modulation. Embryos experienced elevated pCO₂ conditions in the perivitelline fluid (>3-fold higher pCO₂ than that of ambient seawater), rendering the medium under-saturated even under ambient conditions. The growth of both embryos and juveniles was unaffected by pH, whereas ⁴⁵Ca incorporation in cuttlebone increased significantly with decreasing pH at both temperatures. This phenomenon of hypercalcification is limited to only a number of animals but does not guarantee functional performance and calls for better mechanistic understanding of calcification processes.     

Bioaccumulation of essential metals (Co,Mn and Zn) in the king scallop <Emphasis Type="Italic">Pecten maximus</Emphasis>: seawater,food and sediment exposures

In order to understand the bioaccumulation of essential metals in filter-feeding mollusks living in soft sediments, the uptake and depuration kinetics of three elements (Co, Mn and Zn) were investigated in the king scallop Pecten maximus exposed via seawater, food, or sediment, using radiotracer techniques. The scallops were collected in April 2005 in the Pertuis Breton, France and acclimated to laboratory conditions for 8 weeks prior to the experimental exposures. Dissolved metals were efficiently bioconcentrated with mean concentration factors (CFs) ranging from 65 (Co) to 94 (Mn) after 7 days of exposure. Feeding experiments using microalgae Skeletonema costatum (diatom) or Isochrysis galbana (flagellate) showed that metal assimilation efficiency (AE) and retention (T _b½) were strongly influenced by food source. For Co, AE was higher when ingested with I. galbana (29 vs. 4%), whereas Mn and Zn AE was higher for S. costatum (82 vs. 44% and 86 vs. 68%, respectively). Transfer factors (TFs) in P. maximus exposed to radiolabelled sediment were 3–4 orders of magnitude lower than CFs. Nevertheless, the fraction of sediment-bound metals that was taken up was efficiently absorbed in scallop tissues (>85%). Whatever the exposure pathway, metals were strongly retained in the kidneys of P. maximus. Due to poor determination of Mn biokinetics (and related parameters) in scallops exposed through sediment, the relative contribution of the three different pathways could be determined only for Co and Zn using a biodynamic model. The particulate pathway (i.e. food or sediment) appeared to be the main route for bioaccumulation of both metals in this scallop. In addition, even though P. maximus displayed different AEs for Co and Zn according to the food, results of the model were only slightly affected, if any, by change in the dietary parameters (AE and depuration rate constant, k _e).