Elevated testosterone advances onset of migratory restlessness in a nearctic-neotropical landbird

The primary cue for initiation of spring migratory restlessness (Zugunruhe) in landbird migrants is photoperiod. Gonadal hormones are known to have a role in the regulation of migratory disposition; however, the extent of their effect is not well understood. We examined the impact of exogenous testosterone on the onset of migratory restlessness in gray catbirds (Dumetella carolinensis). Catbirds were stratified by sex and randomly assigned to two rooms; individuals in one room were photoadvanced to initiate migratory restlessness and the other room was maintained on a 12:12 light/dark photoperiod. Each room had three groups (n?=?10/group); males with testosterone implants, males with empty implants, and females. We predicted that in the photoadvanced room males with testosterone implants would initiate migratory activity earlier than empty-implanted males. We found that in the photoadvanced group, testosterone-implanted males initiated migration 2 weeks prior to empty-implanted males, and 3 weeks prior to females. In the non-photoadvanced males, the testosterone-implanted males initiated migration at the same time as the corresponding group in the photoadvanced room, while the empty-implanted males and females did not exhibit Zugunruhe. Our results illustrate that elevated testosterone can advance the onset of Zugunruhe, even in the absence of an extended photoperiod. Additionally, the onset of migratory restlessness observed in the photoadvanced, non-testosterone-implanted males and females further supports the importance of photoperiod as a cue for migratory restlessness. An interesting observation was the intersexual differences in the onset of migratory activity in gray catbirds, a species not previously known to exhibit protandry.     

Soil solution and sugar maple response to NH4NO3 additions in a base-poor northern hardwood forest of Québec, Canada

Nitrogen additions (NH4NO3) at rates of three- and ten-fold ambient atmospheric deposition (8.5 kg ha(-1) year(-1)) were realised in an acid- and base-poor northern hardwood forest of Québec, Canada. Soil solution chemistry, foliar chemistry, crown dieback and basal area growth of sugar maple (Acer saccharum Marsh.) were measured. Except for a transitory increase of NO3 and NH4 concentrations, there was no persistent increase in their level in soil solution 3 years after N treatments, with the exception of one plot out of three, that received the highest N addition, beginning to show persistent and high NO3 concentrations after 2 years of N additions. Three years of N additions have significantly increased the N DRIS index of sugar maple but not N foliar concentration. Potassium, Ca and Mn foliar concentrations, as well as P and Ca DRIS indices, decreased in treated plots after 3 years. No treatment effect was observed for basal area growth and dieback rate. One unexpected result was the significant decrease in foliar Ca even in the treated plots that received low N rates, despite the absence of significant NO3-induced leaching of Ca. The mechanism responsible for the decrease in foliar Ca is not known. Our results, however, clearly demonstrate that increased N deposition at sites with low base saturation may affect Ca nutrition even when clear signs of N saturation are not observed.     

Quantitation of persistent organic pollutants adsorbed on plastic debris from the Northern Pacific Gyre's "eastern garbage patch"

Floating marine plastic debris was found to function as solid-phase extraction media, adsorbing and concentrating pollutants out of the water column. Plastic debris was collected in the North Pacific Gyre, extracted, and analyzed for 36 individual PCB congeners, 17 organochlorine pesticides, and 16 EPA priority PAHs. Over 50% contained PCBs, 40% contained pesticides, and nearly 80% contained PAHs. The PAHs included 2, 3 and 4 ring congeners. The PCBs were primarily CB-11, 28, 44, 52, 66, and 101. The pesticides detected were primarily p,p-DDTs and its metabolite, o,p-DDD, as well as BHC (a,b,g and d). The concentrations of pollutants found ranged from a few ppb to thousands of ppb. The types of PCBs and PAHs found were similar to those found in marine sediments. However, these plastic particles were mostly polyethylene which is resistant to degradation and although functioning similarly to sediments in accumulating pollutants, these had remained on or near the ocean surface. Particles collected included intact plastic items as well as many pieces less than 5 mm in size.     

EPA’S Federal Technology Transfer Act Program

In 1986, the Federal Technology Transfer Act (FTTA) was established to promote a closer, collaborative relationship between federal government agencies and the private sector. With the increasing need for new cost-effective technologies to prevent and control pollution, both the U.S. Environmental Protection Agency and private industry are encouraged to facilitate the transfer of knowledge and technology under this Act. The FTTA removed several of the legal and institutional barriers to cooperative research that existed before the Act's passage. Through the FTTA, the government strives to promote the movement of its products, processes, skills and knowledge into the private sector for further development and commercialization by encouraging the exchange of technical personnel and the sharing of facilities and other resources. Collaborative efforts among industry, federal agencies and academia are made possible through cooperative research and development agreements (CRDAs). Thirty-three CRDAs and four licensing agreements have been initiated with EPA under the program. This paper provides an overview of this new and innovative program.     

Generation of Ensemble Streamflow Forecasts Using an Enhanced Version of the Snowmelt Runoff Model1

Harshburger, Brian J., Von P. Walden, Karen S. Humes, Brandon C. Moore, Troy R. Blandford, and Albert Rango, 2012. Generation of Ensemble Streamflow Forecasts Using an Enhanced Version of the Snowmelt Runoff Model. Journal of the American Water Resources Association (JAWRA) 48(4): 643‐655. DOI: 10.1111/j.1752‐1688.2012.00642.x Abstract: As water demand increases in the western United States, so does the need for accurate streamflow forecasts. We describe a method for generating ensemble streamflow forecasts (1‐15 days) using an enhanced version of the snowmelt runoff model (SRM). Forecasts are produced for three snowmelt‐dominated basins in Idaho. Model inputs are derived from meteorological forecasts, snow cover imagery, and surface observations from Snowpack Telemetry stations. The model performed well at lead times up to 7 days, but has significant predictability out to 15 days. The timing of peak flow and the streamflow volume are captured well by the model, but the peak‐flow value is typically low. The model performance was assessed by computing the coefficient of determination (R²), percentage of volume difference (Dv%), and a skill score that quantifies the usefulness of the forecasts relative to climatology. The average R² value for the mean ensemble is >0.8 for all three basins for lead times up to seven days. The Dv% is fairly unbiased (within ±10%) out to seven days in two of the basins, but the model underpredicts Dv% in the third. The average skill scores for all basins are >0.6 for lead times up to seven days, indicating that the ensemble model outperforms climatology. These results validate the usefulness of the ensemble forecasting approach for basins of this type, suggesting that the ensemble version of SRM might be applied successfully to other basins in the Intermountain West.     

Can spatial isolation help predict dispersal-limited sites for native species restoration?

When the distribution of species is limited by propagule supply, new populations may be initiated by seed addition, but identifying suitable sites for efficiently targeted seed addition remains a major challenge for restoration. In addition to the biotic or abiotic variables typically used in species distribution models, spatial isolation from conspecifics could help predict the suitability of unoccupied sites. Site suitability might be expected to increase with spatial isolation after other factors are accounted for, since isolation increases the chance that a site is unoccupied only because of propagule limitation. For two native annual forbs in Californian grasslands, we combined experimental seeding and niche modeling to ask whether suitability of unoccupied sites could be predicted by spatial variables (either distances from, or densities of, conspecific populations), either by themselves or in combination with niche models. We also asked whether experimental tests of these predictions held up not only in the short term (one year), but also in the longer term (three years). For Lasthenia californica, seed additions were only successful relatively near existing populations. For Lupinus nanus, seeding success was low and was positively related to the number of conspecifics within 1 km. For both species, a few previously unoccupied sites remained occupied three years after seeding, but this subset was not predictable based on either spatial or niche variables. Seed addition alone may be a limited means of native forb restoration if suitable unoccupied sites are either rare or unpredictable, or if they tend to be close to where the species already occurs.     

Chemical residence time and hydrological conditions influence treatment of fipronil in vegetated aquatic mesocosms

Fipronil, a phenyl-pyrazole insecticide, is often used in rice (Oryza sativa L.) production agriculture, with elevated runoff concentrations and loads having potential toxicological effects on downstream aquatic environments. This study evaluated two species of aquatic plants-broadleaf cattail (Typha latifolia L.) and powdery alligator-flag (Thalia dealbata Fraser ex Roscoe)-placed in series against a nonvegetated mesocosm in reducing concentrations and loads of fipronil, and associated metabolites. Vegetation type and hydrological condition (inundated vs. dry) were treatment effects used for comparison. The vegetated mesocosms significantly reduced higher loads and concentrations of fipronil, fipronil sulfone, and sulfide in both inundated and dry hydrological conditions over nonvegetated nesocosms. Under inundation conditions, vegetated mesocosms reduced >50% of influent fipronil concentrations and betweeen 60 and 70% of fipronil loads, which was significantly higher than the dry conditions (10-32% concentration and load). These results show that agricultural management strategies usingephemeral aquatic zones, such as drainage ditches, can be optimized to couple chemical applications with vegetation presence and hydrology to facilitate the reduction in chemical waste loads entering downstream aquatic ecosystems. Such reduction is critical for use with fipronil, where negative impacts have been demonstrated with several nontarget species.     

Subsurface application of poultry litter in pasture and no-till soils

Poultry litter provides a rich nutrient source for crops, but the usual practice of surface-applying litter can degrade water quality by allowing nutrients to be transported from fields in surface runoff while much of the ammonia (NH3)-N escapes into the atmosphere. Our goal was to improve on conventional titter application methods to decrease associated nutrient losses to air and water while increasing soil productivity. We developed and tested a knifing technique to directly apply dry poultry litter beneath the surface of pastures. Results showed that subsurface litter application decreased NH3-N volatilization and nutrient losses in runoff more than 90% (compared with surface-applied litter) to levels statistically as low as those from control (no litter) plots. Given this success, two advanced tractor-drawn prototypes were developed to subsurface apply poultry litter in field research. The two prototypes have been tested in pasture and no-till experiments and are both effective in improving nutrient-use efficiency compared with surface-applied litter, increasing crop yields (possibly by retaining more nitrogen in the soil), and decreasing nutrient losses, often to near background (control plot) levels. A paired-watershed study showed that cumulative phosphorus losses in runoff from continuously grazed perennial pastures were decreased by 55% over a 3-yr period if the annual poultry litter applications were subsurface applied rather than surface broadcast. Results highlight opportunities and challenges for commercial adoption of subsurface poultry litter application in pasture and no-till systems.     

Perceptions of Community Benefits from Two Wild and Scenic Rivers

Wild and Scenic Rivers provide a host of psychological, social, ecological, and economic benefits to local communities. In this study, we use data collected from recreational users of two Wild and Scenic Rivers to examine perceptions of the benefits provided by the rivers to local communities. Our purposes are (1) to determine if similar perceptions of community benefits exist across the two rivers, (2) to determine if individuals’ proximity to the rivers are related to the benefits they perceive, (3) to determine if individuals’ prior recreation experience on the river is related to variations in perceived benefits, (4) to determine if users’ sociodemographic characteristics are related to perceived community benefits, and (5) to determine if the influence of these characteristics on perceived community benefits is similar across the two resource areas. Perceived benefits were found to be analogous across both rivers as individuals consistently ranked ecological/affective benefits as well as tangible benefits similarly. Recreationists living further from the river ranked ecological and affective benefits as significantly less important than those individuals living closer to the river. Women perceived the community benefits produced by the resource areas to be significantly more important when compared to men. Significant relationships were also found between perceived benefits and recreationists’ previous use of the river, their age, and their level of education. With the exception of resource proximity and prior use history, the effects of user characteristics on perceived community benefits were not statistically different across the two rivers. These findings imply similar patterns of perceived community benefits exist across distinct resource areas and that the relationships between user characteristics and perceived benefits are also similar across the study rivers.     

Changes in persistent contaminant concentration and CYP1A1 protein expression in biopsy samples from northern bottlenose whales, Hyperoodon ampullatus, following the onset of nearby oil and gas development

A small population of endangered northern bottlenose whales (Hyperoodon ampullatus) inhabits "The Gully" a Marine Protected Area on the Scotian Shelf, eastern Canada. Amid concerns regarding nearby oil and gas development, we took 36 skin and blubber biopsy samples in 1996-1997 (prior to major development) and 2002-2003 (five years after development began), and three samples from a population in the Davis Strait, Labrador in 2003. These were analysed for cytochrome P4501A1 (CYP1A1) protein expression (n=36), and for persistent contaminants (n=23). CYP1A1 showed generally low expression in whales from The Gully, but higher levels during 2003, potentially coincident with recorded oil spills, and higher levels in Davis Strait whales. A range of PCB congeners and organochlorine compounds were detected, with concentrations similar to other North Atlantic odontocetes. Concentrations were higher in whales from The Gully than from the Davis Strait, with significant increases in 4,4'-DDE and trans-nonachlor in 2002-2003 relative to 1996-1997.