Natural and anthropogenic hydrocarbon inputs to sediments of Patos Lagoon Estuary, Brazil

The Patos Lagoon Estuary, southern Brazil, is an area of environmental interest not only because of tourism, but also because of the presence of the second major port of Brazil, with the related industrial and shipping activities. Thus, potential hydrocarbon pollution was examined in this study. Sediment samples were collected at 10 sites in the estuary, extracted, and analyzed by GC-FID and GC-MS for composition and concentration of the following organic geochemical markers: normal and isoprenoid alkanes, petroleum biomarkers, linear alkylbenzenes (LABs), and polycyclic aromatic hydrocarbons (PAHs). The total concentrations varied from 1.1 to 129.6 microg g(-1) for aliphatic hydrocarbons, from 17.8 to 4510.6 ng g(-1) for petroleum biomarkers, from 3.2 to 1601.9 ng g(-1) for LABs, and from 37.7 to 11,779.9 ng g(-1) for PAHs. Natural hydrocarbons were mainly derived from planktonic inputs due to a usual development of blooms in the estuary. Terrestrial plant wax compounds prevailed at sites located far from Rio Grande City and subject to stronger currents. Anthropogenic hydrocarbons are related to combustion/pyrolysis processes of fossil fuel, release of unburned oil products and domestic/industrial waste outfalls. Anthropogenic hydrocarbon inputs were more apparent at sites associated with industrial discharges (petroleum distributor and refinery), shipping activities (dry docking), and sewage outfalls (sewage). The overall concentrations of anthropogenic hydrocarbons revealed moderate to high hydrocarbon pollution in the study area.     

Decrease in water-soluble 17beta-Estradiol and testosterone in composted poultry manure with time

Little attention has been paid to the environmental fate of the hormones 17beta-estradiol and testosterone excreted in animal waste. Land application of manure has a considerable potential to affect the environment with these endocrine disrupting compounds (EDCs). Composting is known to decompose organic matter to a stable, humus-like material. The goal of the present study was to quantitatively assess levels of water-soluble 17beta-estradiol and testosterone in composting chicken manure with time. Chicken layer manure was mixed with hay, straw, decomposed leaves, and starter compost, adjusted to approximately 60% moisture, and placed into a windrow. A clay-amended windrow was also prepared. Windrows were turned weekly, and temperature, oxygen, and CO(2) in the composting mass were monitored for either 133 or 139 d. Commercial enzyme immunoassay kits were used to quantitate the levels of 17beta-estradiol and testosterone in aqueous sample extracts. Water-soluble quantities of both hormones diminished during composting. The decrease in 17beta-estradiol followed first-order kinetics, with a rate constant k = -0.010/d. Testosterone levels declined at a slightly higher rate than 17beta-estradiol (i.e., k = -0.015/d). Both hormones could still be measured in aqueous extracts of compost sampled at the conclusion of composting. The decline in water-soluble 17beta-estradiol and testosterone in extracts of clay-amended compost was not statistically different from normal compost. These data suggest that composting may be an environmentally friendly technology suitable for reducing, but not eliminating, the concentrations of these endocrine disrupting hormones at concentrated animal operation facilities.     

Echolocation,development, and vocal communication in the lesser bulldog bat,Noctilio albiventris

Summary Foraging and echolocation behavior and its ontogeny in the lesser bulldog bat, Noctilio albiventris, were studied in Panama under field and captive conditions. The vocalizations utilized for echolocation and communication were monitored. Adult N. albiventris captured insect prey from the water surface employing various combinations of CF/FM (constant frequency and frequency modulated) signals. The proportions of CF/FM and the repetition rate were a function of the bat's activity. Most adults exhibited post-sunset and pre-dawn foraging activity, although several telemetered lactating females foraged for only the half hour after dusk, spending the rest of the night with their babies in the roost. When the juveniles began to leave the roost at the age of two months, they appeared to accompany their mothers on initial flights.Captive infant Noctilio developed slowly, and did not fly until about 5–6 weeks postnatally. They continued to nurse for almost 3 months, even though they were capable of eating solid food at about 6 weeks. Previous to weaning, mothers fed their infants with masticated food from their cheekpouches.At birth, Noctilio emit a combination of long FM isolation calls and shorter CF/FM pulses. Mothers nurse only their own babies which they appear to recognize by a vocal signature contained in the infants' isolation calls. The individual isolation calls, as well as the mother's communication sounds, appear to be variations of an FM sinusoidal wave. The periodicity and amplitude change, and different portions including harmonics are added or deleted. The short CF/FM signals of the infant evolve into the adult orientation type signals as the CF component increases in frequency and the repetition rate increases. These sounds appear to serve a dual function in communication and echolocation. Mother-young pairs were observed to call antiphonally, utilizing CF/short FM signals in retrieval situations. This duetting was also observed in bats flying over the Chagras River after the time the juveniles began to fly, and may function to maintain vocal contact during initial foraging flights.Deceased     

Behavioral correlations with aberrant patterns in humpback whale songs

Summary Humpback whales emit long, patterned vocalizations referred to as songs. We analyzed songs from 22 recording sessions whick took place from January to April, 1980 on Silver Bank, Dominican Republic. The sequence of patterns (which we call themes) in these songs is remarkably regular. In this sample, there were 427 transitions from one theme to another. Only 20 of these did not follow the expected sequence. We present evidence that some themes are sung out of their usual order far more often than others. We also show that when themes are sung out of sequence, the whale is at the surface, blowing. This finding provides a link between the song structure and humpback behavior. Because aspects of the song structure can be linked to breathing, we hypothesize that a function of the songs is to show how long a whale can hold its breath, and that the duration of a song may be an indication of stamina and physical condition.     

Males are selective too: mating, but not courtship, with sequential females influences choosiness in male field crickets (Gryllus bimaculatus)

Mate choice experiments have generally focused on female choice; few have considered that males can also be selective. We examined courtship in male field crickets sequentially introduced to four females of differing size. Large (L) and small (S) females were introduced in order of either LSLS or SLSL. We demonstrate that naive males invest equally (courtship effort) in the first female they meet, regardless of her size, but show greater courtship effort when they subsequently encounter large compared with small females. Moreover, we demonstrate that males show this discriminatory behavior when they are permitted to mate with females (i.e. use a spermatophore) but are less choosy when the female is removed before spermatophore transfer.     

Comparison of beach bacterial water quality indicator measurement methods

Three methods (membrane filtration, multiple tube fermentation, and chromogenic substrate technology kits manufactured by IDEXX Laboratories, Inc.) are routinely used to measure indicator bacteria for beach water quality. To assess comparability of these methods, quantify within-laboratory variability for each method, and place that variability into context of variability among laboratories using the same method, 22 southern California laboratories participated in a series of intercalibration exercises. Each laboratory processed three to five replicates from thirteen samples, with total coliforms, fecal coliforms or enterococci measured depending on the sample. Results were generally comparable among methods, though membrane filtration appeared to underestimate the other two methods for fecal coliforms, possibly due to clumping. Variability was greatest for the multiple tube fermentation method. For all three methods, within laboratory variability was greater than among laboratories variability.     

Evaluation of preservation methods for nutrient species collected by automatic samplers

Automatic samplers are a common method of data collection for numerous monitoring projects in the South Florida region and elsewhere. Although total phosphorus (TP) is the primary parameter of interest within this region, nitrogen species such as ammonia nitrogen (NH₄-N), nitrate+nitrite nitrogen (NO_x-N), and total kjeldahl nitrogen (TKN) are also collected and analyzed. Federal and state quality assurance guidelines require nutrient samples to be preserved by acidification with H₂SO₄ to a pH < 2 and stored immediately at 4 °C. However, the remoteness of manysampling locations in South Florida makes it difficult to supplyelectricity for the refrigeration of samples collected by autosamplers. In addition, the use of propane-powered refrigerated autosamplers is a costly and ineffective solution in the South Florida climate. Consequently, while samples collected at these remote locations are routinely pre-preservedwith acid, they are not cooled to 4 °C for a period fromone to seven days. This study evaluated if a statistically significant difference ( = 0.05) existed between concentrations of nitrogen species from a common source samplethat was either: processed immediately; refrigerated to 4 °C for seven days; or not refrigerated for seven days.In all cases, the collected sample was pre-preserved by adding 1 mL of 50% H₂SO₄ to each 1 L discrete sample container before each 7 day testing period. Differences in concentrations of the calculated parameter total nitrogen (TN)were also investigated.Analyses using the Wilcoxon Signed-Rank Test showed no significant differences among the three treatment groups for NO_x-N, TKN, TN and TP. Significant differences were observedwhen the NH₄-N samples that were processed immediately werepaired with NH₄-N samples that were left unrefrigerated or refrigerated for seven days. Information from this study can be used by researchers and managers in evaluating the usefulness of nutrient water quality data that is collected when sample refrigeration is not available.     

Monitoring trace metals in urban aerosols from Buenos Aires city. Determination by plasma-based techniques

A study was undertaken, within the framework of a 3 years national project, to assess the content of 13 elements in airborne particulate matter collected in representative zones of the metropolitan area of Buenos Aires. The sampling strategy followed consisted in collecting simultaneously 67 samples of PM10 particulate matter in 9 sampling sites covering an area of about 30 km2 during one week. The collection was performed on ash-free fibre-glass filters using high volume samplers. A combination of aqua regia and perchloric acid was used for leaching metals from filters. Key elements, namely Al, Ca, Cu, Fe, Mn, Mo, Ni, Pb, S, Sb, Sn, Zn and Zr, were determined by inductively coupled plasma-optical emission spectrometry (ICP-OES) and inductively coupled plasma-mass spectrometry (ICP-MS) at micro g g(-1) and ng g(-1) levels. Analyte concentration varied from 130 ng g(-1)(Mo) to over 30%(Ca). Multivariate statistical analysis was performed on the data set including the measured elemental compositions for the monitored period. The atmospheric concentration found for Pb confirms the decreasing levels of this element since the introduction of unleaded gasoline in 1995: 88 ng m(-3)(2001) < 220 ng m(-3)(1997) < 3900 ng m(-3)(1994). The average S concentration above 3 microg m(-3) is somehow unexpectedly high for Buenos Aires since the relatively low S content of liquid fuels and the massive usage of natural gas imply low emissions of this element from combustion activities. To the best of our knowledge, S concentrations are reported for the first time for this city.     

Ambient toxicity due to chlorpyrifos and diazinon in a central California coastal watershed

The Salinas River watershed along the central coast of California, U.S.A., supports rapidly growing urban areas and intensive agricultural operations. The river drains to an estuarine National Wildlife Refuge and a National Marine Sanctuary. The occurrence, spatial patterns, sources and causesof aquatic toxicity in the watershed were investigated by sampling four sites in the main river and four sites in representative tributaries during 15 surveys between September1998 and January 2000. In 96 hr toxicity tests, significant Ceriodaphnia dubia mortality was observed in 11% of the mainriver samples, 87% of the samples from a channel draining anurban/agricultural watershed, 13% of the samples fromchannels conveying agricultural tile drain runoff, and in 100% of the samples from a channel conveying agricultural surface furrow runoff. In six of nine toxicity identificationevaluations (TIEs), the organophosphate pesticides diazinon and/or chlorpyrifos were implicated as causes of observed toxicity, and these compounds were the most probable causes oftoxicity in two of the other three TIEs. Every sample collectedin the watershed that exhibited greater than 50% C. dubia mortality (n = 31) had sufficient diazinon and/or chlorpyrifos concentrations to account for the observed effects.Results are interpreted with respect to potential effects on other ecologically important species.     

Understanding Human–Landscape Interactions in the “Anthropocene”

This article summarizes the primary outcomes of an interdisciplinary workshop in 2010, sponsored by the U.S. National Science Foundation, focused on developing key questions and integrative themes for advancing the science of human–landscape systems. The workshop was a response to a grand challenge identified recently by the U.S. National Research Council (2010a)—“How will Earth’s surface evolve in the “Anthropocene?”—suggesting that new theories and methodological approaches are needed to tackle increasingly complex human–landscape interactions in the new era. A new science of human–landscape systems recognizes the interdependence of hydro-geomorphological, ecological, and human processes and functions. Advances within a range of disciplines spanning the physical, biological, and social sciences are therefore needed to contribute toward interdisciplinary research that lies at the heart of the science. Four integrative research themes were identified—thresholds/tipping points, time scales and time lags, spatial scales and boundaries, and feedback loops—serving as potential focal points around which theory can be built for human–landscape systems. Implementing the integrative themes requires that the research communities: (1) establish common metrics to describe and quantify human, biological, and geomorphological systems; (2) develop new ways to integrate diverse data and methods; and (3) focus on synthesis, generalization, and meta-analyses, as individual case studies continue to accumulate. Challenges to meeting these needs center on effective communication and collaboration across diverse disciplines spanning the natural and social scientific divide. Creating venues and mechanisms for sustained focused interdisciplinary collaborations, such as synthesis centers, becomes extraordinarily important for advancing the science.