Effect of field exposure to 38-year-old residual petroleum hydrocarbons on growth, condition index, and filtration rate of the ribbed mussel, Geukensia demissa

In September 1969, the Florida barge spilled 700,000 L of No. 2 fuel oil into the salt marsh sediments of Wild Harbor, MA. Today a substantial amount, approximately 100 kg, of moderately degraded petroleum remains within the sediment and along eroding creek banks. The ribbed mussels, Geukensia demissa, which inhabit the salt marsh creek bank, are exposed to the spilled oil. Examination of short-term exposure was done with transplantation of G. demissa from a control site, Great Sippewissett marsh, into Wild Harbor. We also examined the effects of long-term exposure with transplantation of mussels from Wild Harbor into Great Sippewissett. Both the short- and long-term exposure transplants exhibited slower growth rates, shorter mean shell lengths, lower condition indices, and decreased filtration rates. The results add new knowledge about long-term consequences of spilled oil, a dimension that should be included when assessing oil-impacted areas and developing management plans designed to restore, rehabilitate, or replace impacted areas.     

Nitrogen deposition increases the acquisition of phosphorus and potassium by heather Calluna vulgaris

Increased plant productivity due to nitrogen pollution increases the strength of the global carbon sink, but is implicated in plant diversity loss. However, modelling and experimental studies have suggested that these effects are constrained by availability of other nutrients. In a survey of element concentrations in Calluna vulgaris across an N deposition gradient in the UK, shoot concentrations of N and more surprisingly phosphorus and potassium were positively correlated with N deposition; tissue N/P ratio even decreased with N deposition. Elevated P and K concentrations possibly resulted from improved acquisition due to additional enzyme production or mycorrhizal activity. Heather occurs on organic soils where nutrient limitations are likely due to availability constraints rather than small stocks. However, if this effect extends to other plant and soil types, effects of N deposition on C sinks and plant competition may not be as constrained by availability of other nutrients as previously proposed.     

Chloride leaching from air pollution control residues solidified using ground granulated blast furnace slag

Ground granulated blast furnace slag (ggbs) has been used to solidify air pollution control (APC) residues obtained from a major UK energy-from-waste plant. Samples were prepared with ggbs additions between 10 and 50 wt% of total dry mass and water/solids ratios between 0.35 and 0.80. Consistence, setting time, compressive strength and leaching characteristics have been investigated. Results indicated that the highly alkaline nature of APC residues due to the presence of free lime can be used to activate ggbs hydration reactions. Increasing ggbs additions and reducing the water content resulted in increased compressive strengths, with 50 wt% ggbs samples having average 28 d strengths of 20.6 MPa. Leaching tests indicate low physical encapsulation and minimal chemical fixation of chloride in ggbs solidified APC residues. The results suggest that more than 50 wt% ggbs additions would be required to treat APC residues to meet the current waste acceptance criteria limits for chloride.     

Measurements of fog water interception by shrubs on the California central coast

Fog water deposition may be an important component of the water budget of herbaceous-shrub ecosystems on the central and southern coastal regions of California. This paper presents the first analysis of measured fog water drip rates and meteorological controls in shrublands of Big Sur, California. Seasonal totals of 1255 mm and 306 mm of fog water drip were recorded in 2014 and 2015 (respectively), for averaged fog deposition rates of 0.02–0.08 l m² hr.^?1 to the soil under shrub canopy cover. The diurnal patterns of fog water drip showed that the majority of all trough water collected under shrubs on no-rain days occurred between the hours of 11 PM and 9 AM. During the study period from June 1 to October 31 of both 2014 and 2015, soil water content decreased significantly from average levels of 4–6 % at the shrub canopy center and middle locations, through 2–3 % VWC at the shrub edge locations, to levels at or below 2 % at 2-m distance locations from the shrub edge in open grass cover. Based on these results, we conclude that detectable rates of shrub canopy fog interception help sustain elevated soil water levels under shrubs and aid woody vegetation survival through periods of low rainfall.     

Sustainability and comanagement of subsistence hunting in an indigenous reserve in Guyana

Although hunting is a key component of subsistence strategies of many Amazonians, it is also one of the greatest threats to wildlife. Because indigenous reserves comprise over 20% of Amazonia, effective conservation often requires that conservation professionals work closely with indigenous groups to manage resource use. We used hunter‐generated harvesting data in spatially explicit biodemographic models to assess the sustainability of subsistence hunting of indigenous Waiwai in Guyana. We collected data through a hunter self‐monitoring program, systematic follows of hunters, and semistructured interviews. We used these data to predict future densities of 2 indicator species, spider monkeys (Ateles paniscus) and bearded sakis (Chiropotes sagulatus), under different scenarios of human population expansion and changing hunting technology. We used encounter rates from transect surveys and hunter catch‐per‐unit effort (CPUE) to validate model predictions. Paca (Cuniculus paca) (198 /year), Currosaw (Crax alector) (168), and spider monkey (117) were the most frequently harvested species. Predicted densities of spider monkeys were statistically indistinguishable from empirically derived transect data (Kolmogorov–Smirnov D = 0.67, p = 0.759) and CPUE (D = 0.32, p = 1.000), demonstrating the robustness of model predictions. Ateles paniscus and C. sagulatus were predicted to be extirpated from <13% of the Waiwai reserve in 20 years, even under the most intensive hunting scenarios. Our results suggest Waiwai hunting is currently sustainable, primarily due to their low population density and use of bow and arrow. Continual monitoring is necessary, however, particularly if human population increases are accompanied by a switch to shotgun‐only hunting. We suggest that hunter self‐monitoring and biodemographic modeling can be used effectively in a comanagement approach in which indigenous parabiologists continuously provide hunting data that is then used to update model parameters and validate model predictions.     

非洲中部生态系统的碳排放及碳截留潜力

<京都议定书>中的<气候变化框架公约共同行动计划>和<清洁开发机制>要求对目前生态系统的碳蓄积、碳通量及碳截留潜力进行科学的理解,特别是对于碳贮库大但碳排放显著的、存在大面积和可重新造林土地的热带生态系统的了解.非洲中部拥有世界上10%的现有热带湿润森林,但有关该地区的碳研究甚少.1980年,非洲中部生态系统地上部分的碳蓄积为28.92Pg,到1990年则减少到24.79Pg.以增加生物量碳密度为目标而改善的森林管理能够截留18.32Pg的碳,到2050年还有超过50万km2原为森林的土地可以重新造林,从而增加截留10Pg的碳.了解生物量碳蓄积及其潜在截留量的空间分布对于通过<共同行动计划>和<清洁开发机制>所启动的碳贸易行动具有重大的意义.     

The use of ultraviolet germicidal irradiation (UVGI) in disinfection of airborne bacteria

Contamination of indoor air by microbial pollutants has been increasingly recognized as a public health problem, and may be responsible for building-related illness (BRI) and sick-building syndrome (SBS). Bioaerosols such as fungi, bacteria, and viruses in indoor air can cause allergic and irritant responses, infectious diseases, respiratory problems, and hypersensitivity reactions. People sensitive to indoor environmental problems complain of a wide variety of symptoms ranging from headache, fatigue, nausea, sinus congestion, to eye, nose, and throat irritations.Although ultraviolet germicidal irradiation (UVGI) with a predominant wavelength of 254 nm has been used for air disinfection for many years to minimize microbial numbers in the air, few quantitative data are available on the radiation susceptibilities of individual airborne microbes. There have been a number of UVGI studies documenting the effectiveness of UVGI for the control of microbes in controlled settings. Many of these studies documented the effectiveness of UVGI against airborne tuberculosis organisms.The studies described here used commercial type fan-powered shielded UVGI-containing fixtures to evaluate their effectiveness in air disinfection. Aerosolization tests were done in the contained environment of a negative pressure bioaerosol stainless steel testing chamber 0.75 m wide·3.7 m long. The chamber was designed so that microbes could be safely aerosolized and contained while traversing the chamber through the UVGI-containing fix-tures. Four commercial (Purair UV Germicidal Systems, Mount Vernon, N.Y.) fan-powered UVGI-containing fix-tures placed in the chamber were individually evaluated for their ability to disinfect individual bioaerosols of air-borne bacteria.Air samples were taken at the inlet and outlet of the UVGI-containing units positioned in the bioaerosol chamber, using Ace Glass all-glass impingers (AGI-30). Five bacterial species were individually aerosolized to evaluate their kill. The bacteria used to test all of the UVGI-containing units were vegetative cells of Escherichia coli, Micrococcus luteus, Pseudomonas fluorescens, Staphylococcus aureus, and endospores of Bacillus subtilis. Based upon the concentration of bioaerosols collected at the inlet and outlet of the fixtures tested, the total overall microbial kills for the four fixtures with the filters in place and the UVGI units on were more than 99% for all the airborne vegetative bacteria tested, and a mean of over 75% for the B. subtilis endospores.All of the fixtures were efficient in the kill of the test vegetative bacteria used, even the more UVGI-resistant M. luteus vegetative cells and endospores of B. subtilis. Units such as these may provide an economical way to supplement existing air cleaning procedures used in indoor environments, and to kill airborne bacteria effectively without human exposure to UV light.     

Changes in the trade in native medicinal plants in Brazilian public markets

Plants continue to be an important source of new bioactive substances. Brazil is one of the world’s mega-diverse countries, with 20 % of the world’s flora. However, the accelerated destruction of botanically rich ecosystems has contributed to a gradual loss of native medicinal species. In previous study, we have observed a fast and intensive change in trade of medicinal plants in an area of Amazon, where human occupation took place. In this study, we surveyed 15 public markets in different parts of Brazil in search of samples of 40 plants used in traditional medicine and present in first edition of Brazilian Official Pharmacopoeia (FBRAS), published in 1926. Samples of plants commercialized as the same vernacular name as in Pharmacopoeia were acquired and submitted to analysis for authentication. A total of 252 plant samples were purchased, but the laboratory analyses showed that only one-half of the samples (126, 50.2 %) were confirmed as the same plant species so named in FBRAS. The high number of unauthenticated samples demonstrates a loss of knowledge of the original native species. The proximity of the market from areas in which the plant occurs does not guarantee that trade of false samples occurs. The impact of the commerce of the substitute species on their conservation and in public health is worrying. Strategies are necessary to promote the better use and conservation of this rich heritage offered by Brazilian biodiversity.     

Predicting System-Scale Impacts of Oyster Clearance on Phytoplankton Productivity in a Small Subtropical Estuary

Oyster populations in south Florida estuaries have declined in part through altered salinity driven by anthropogenic changes in freshwater inputs. In particular, the St. Lucie Estuary (SLE) in southeastern Florida has suffered widespread loss of oyster habitat. With efforts underway to improve water quality and oyster habitat in the SLE, the goal of this study was to develop a model to assess ecosystem level impacts of oyster restoration. Phytoplankton and oyster biomass modeling targets were established from observational data collected from 2005 to 2009. Modeled oyster biomass production and filtration fluctuated with temperature, salinity, and total suspended solids from a combination of observational and predicted input functions in 10-year simulations (1998–2007). Model estimates of oyster biomass fluctuated with salinity from near zero after extreme freshwater discharge in 2002–2003 and 2004–2005 to maximum values near 150.0 and 200.0 g?C?m^?2 in spring 1999 and fall 2006. There was potential for algal blooms as turnover time for the phytoplankton standing stock (15.6 days) was faster than water mass turnover (21.0 days). While >1,000 days were required for 50 ha of oyster habitat to filter the entire volume of the estuarine segment, filter time reduced to <20 days with an estimated fivefold increase in net consumption of phytoplankton if the oyster habitat was increased to 300 ha. Re-establishment of biologically desirable salinity envelopes would stabilize oyster survival allowing the possibility for successful habitat restoration to benefit water quality and faunal attributes of the St. Lucie Estuary.