Locating Sampling Sites Research Articles

Wind turbine wakes can impact down-wind vegetation greenness

Global wind energy has expanded 5-fold since 2010 and is predicted to expand another 8–10-fold over the next 30 years. Wakes generated by wind turbines can alter downwind microclimates and potentially downwind vegetation. However, the design of past studies has made it difficult to isolate the impact of wake effects on vegetation from land cover change. We used hourly wind data to model wake and non-wake zones around 17 wind facilities across the U.S. and compared remotely-sensed vegetation greenness in wake and non-wake zones before and after construction. We located sampling sites only in the dominant vegetation type and in areas that were not disturbed before or after construction. We found evidence for wake effects on vegetation greenness at 10 of 17 facilities for portions of, or the entire growing season. Evidence included statistical significance in Before After Control Impact statistical models, differences >3% between expected and observed values of vegetation greenness, and consistent spatial patterns of anomalies in vegetation greenness relative to turbine locations and wind direction. Wakes induced both increases and decreases in vegetation greenness, which may be difficult to predict prior to construction. The magnitude of wake effects depended primarily on precipitation and to a lesser degree aridity. Wake effects did not show trends over time following construction, suggesting the changes impact vegetation greenness within a growing season, but do not accrue over years. Even small changes in vegetation greenness, similar to those found in this study, have been seen to affect higher trophic levels. Given the rapid global growth of wind energy, and the importance of vegetation condition for agriculture, grazing, wildlife, and carbon storage, understanding how wakes from wind turbines impact vegetation is essential to exploit or ameliorate these effects.

PCDD/PCDFs and PCBs in the irrigation water in Egypt: levels, patterns, and potential sources.

The contamination levels of PCDD/PCDFs in irrigation water are the most rarely studied throughout the world. The major problem in Egypt is the lack of studies andstatistics about these contaminants of POPs in irrigation water. Therefore, this study is the first comprehensive report to elucidate the estimation and sources of PCDD/PCDFs and PCBs in irrigation water from Egypt and rare for worldwide may provide a reference to future studies of POPs compounds in irrigation water of Egypt. A total of 24 irrigated water samples were collected from different irrigation canals which are adjacent to industrial areas from six Egyptian governorates (Bani Swef, El-Giza, El-Sharkeya, El-Menoufeya, El-Gharbeya, and Alexandria). The study shows that irrigation water canals were contaminated with low levels of PCDDs/PCDFs, which were 0.95pgWHO-TEQ/l, and the total of PCDD/PCDFs and dl-PCBs were 2.06 pgWHO-TEQ/l with contamination ranging between 0.88 to 2.97 pgWHO-TEQ/l while the levels of indicator PCBs were 18.52ng/l and ranged between 0.39 to 165.6ng/l. The most predominant dioxins congeners were HpCDD, OCDD, HpCDF, and OCDF while for dl-PCBs were PCB105 and PCB118, and for ndl-PCBs was PCB138. The areas with recent urbanization and industrialization were more contaminated with PCBs than the unindustrialized area. Lightly to moderately chlorinated congeners dominated the PCB profiles. The major sources for these contaminants were fire bricks followed by textile industries closer to the located sampling sites. The detected pattern was found to be similar to the patterns reported in the air by other studies. Although the concentrations of the studied POPs are found to be low in irrigated water, it may be considered as a potential source of soil pollution due to their accumulation process in the agricultural land and may lead to risk on human health by consuming the agricultural products irrigated by contaminated water.

Feeding range of age 1+ year Eurasian perch Perca fluviatilis in the Baltic Sea.

Using the widespread Eurasian perch Perca fluviatilis as a model organism, feeding ranges were investigated using stable-isotope ratios (δ15 N and δ13 C) and body condition. Differences were found between closely located sampling sites in a littoral area without obvious migration barriers, indicating that individual fish had small feeding ranges. Body condition differences between sampled stations were consistent over 4 years. Such sedentary behaviour is important to consider in, e.g. fisheries management and environmental monitoring, as local catch regulations may be meaningful or geographic stability in sampling locations may reduce noise in data.

Variability of bioturbation in various sediment types and on different spatial scales in the southwestern Baltic Sea

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 557:31-49 (2016) - DOI: https://doi.org/10.3354/meps11837 Variability of bioturbation in various sediment types and on different spatial scales in the southwestern Baltic Sea Claudia Morys*, Stefan Forster, Gerhard Graf Department Marine Biology, University of Rostock, Albert-Einstein-Str. 3, 18059 Rostock, Germany *Corresponding author: claudia.morys@uni-rostock.de ABSTRACT: Variability of bioturbation on different spatial scales was revealed through a survey at 6 stations in the southwestern Baltic Sea with different sediment types, salinities and macrozoobenthic communities. At each station, 6 sampling locations were investigated with 4 cores each (24 cores per station). The cores were analyzed for vertical chlorophyll (chl) profiles, which were modeled with both a local (tracer distribution decreasing exponentially with depth indicative of diffusive transport, DB) and a non-local (presence of subsurface maximum of the tracer, injection flux J and ingestion rate r) mixing model developed by Soetaert et al. (1996; J Mar Res 54:1207–1227). Degradation of chl was determined experimentally by an incubation of fresh sediment under anoxic, dark conditions and provided decay constants kD of 0.01 d-1 for mud and 0.02 d-1 for sand. Mixing depths reach 7.1 ± 1.6 cm at stations in the west (except Lübeck Bay, LB), 2 cm deeper than at stations in the east, which reach 5.2 ± 1.7 cm (including LB), mainly depending on the macrozoobenthic community present. Bioturbation intensities indicate high variability between closely located sampling sites as well as across the southern Baltic Sea, and depend on the food supply from the water column. Stations indicate a difference in local mixing (DB) of a factor of 20 and in non-local processes (J) of 6. Non-local transports account for 33 to 50% of the investigated area in the west and for 70 to 100% in the east. The statistical description of the results indicates the necessity of high sampling effort when using chl as a particle tracer. KEY WORDS: Bioturbation · Local and non-local transport · Chlorophyll degradation · Mixing depth Full text in pdf format PreviousNextCite this article as: Morys C, Forster S, Graf G (2016) Variability of bioturbation in various sediment types and on different spatial scales in the southwestern Baltic Sea. Mar Ecol Prog Ser 557:31-49. https://doi.org/10.3354/meps11837 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 557. Online publication date: September 28, 2016 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2016 Inter-Research.

Original specimens and type localities of early described polychaete species (Annelida) from Norway, with particular attention to species described by O.F. Müller and M. Sars

Oug, E., Bakken, T. and Kongsrud, J.A. 2014. Original specimens and type localities of early described polychaete species (Annelida) from Norway, with particular attention to species described by O.F. Muller and M. Sars. Memoirs of Museum Victoria 71: 217–236. Early descriptions of species from Norwegian waters are reviewed, with a focus on the basic requirements for reassessing their characteristics, in particular, by clarifying the status of the original material and locating sampling sites. A large number of polychaete species from the North Atlantic were described in the early period of zoological studies in the 18th and 19th centuries. The descriptions were often short or referred solely to general characteristics, which by today’s standards are considered inadequate for species discrimination. As a result, a number of taxa among the so-called ‘wellknown and widely distributed’ species have later been confused with morphologically similar species. Close to 100 presently valid species were described from Norwegian waters before 1900. The most prolific contributions were made by O.F. Muller (with about 20 species from 1771–1776) and Michael Sars (with more than 50 species from 1829–1872). Other authors in the 19th century included Anders Orsted, Heinrich Rathke and Gerhard Armauer Hansen. Descriptions were mostly in Latin (O.F. Muller) or in Norwegian or Danish with the diagnosis in Latin (M. Sars and contemporary naturalists). Original material from O.F. Muller is not known to exist. Original material from M. Sars and contemporary scientists does still exist, but is often not identified as original (‘syntypes’) and is occasionally spread over several museum collections. Locating original sampling localities (‘type localities’) has been achieved by combining information from various literature sources, labels of original material (when extant), and knowledge of historic place names.

Genetic structure among earthworms ( Lumbricus terrestris L.) from different sampling sites in western Germany based on random amplified polymorphic DNA

Summary Earthworms are being used as bio-indicators to assess terrestrial pollution. However, it is often not known whether their populations possess a uniform genetic structure, which would allow comparison of residues or biological properties of earthworms from different sampling locations. In order to investigate this point, random amplified polymorphic DNA (RAPD) variation was surveyed in earthworms ( Lumbricus terrestris ) from five different sampling sites in Germany. Forty oligonucleotide RAPD primers (10 base pairs in length) were screened, three of which produced high polymorphic band patterns. A total of 61 DNA fragments were detected in 90 individuals of L. terrestris from five sampling sites with 49 (80.3%) RAPD markers being polymorphic. The genetic similarities within (band sharing rates between 0.756 and 0.795) and among the L. terrestris populations (0.635) were similar even at widely separate locations. Inter-population variation in the RAPD pattern for all five earthworm populations accounted for 37.9% of the total variation, while intra-population variation for three adjacent Saarland populations accounted for only 18.0% of the total variation. Principal component analysis (PCA) and the genetic distances of the populations confirm these results. Twenty-four percent of the genetic distance is caused by geographical isolation as shown by a test for isolation by distance. These results show that L. terrestris fulfils the genetic qualifications for a bio-indicator particularly at closely located sampling sites. However, the results also suggest that earthworm studies of widely separated locations should include genetic characterisation of the earthworm samples.

Evidence for decrease in atmospheric sulfur burden in the eastern United States caused by reduction in SO2 emissions

We report aerosol SO42− measurements from 1979 to 1996 at Whiteface Mountain located in the Adirondack Mountains and from 1983 at Mayville, in western New York State. From 1981 to 1991 SO42− decreased, ∼3% per year. Reductions of nearly 47% in SO42− and total sulfur concentrations at Whiteface Mountain, and about 30% at Mayville, were observed during 1995 to 96 compared with the mean levels during 1981–91, while the upwind SO2 emissions in the Midwestern United States decreased by 36%. Linear relationships between SO42− and total sulfur concentrations and the SO2 emissions were observed for the entire period. The mean ratio of SO42− concentrations to SO2 emissions for the eighteen year period at Whiteface Mountain is 0.11 ± 0.014 and for thirteen years at Mayville is 0.23± 0.014 µg SO42−/m³ per 10³ metric tons SO2 emitted per day. The data suggest that the observed relationship could be used to predict decreases in atmospheric SO42− levels based on SO2 emissions several years hence. Furthermore, it appears feasible to develop an empirical source‐receptor relationship if similar data were acquired from a network of strategically located sampling sites.

Evaluating GIS for Establishing and Monitoring Environmental Conditions of Oil Fields: ABSTRACT

Good management of an oil field and compliance with ever-increasing environmental regulations is enhanced by technologies that improve a company`s understanding of field/production facilities and environmental conditions that have occurred to both through time. In Nigeria, Kazakhstan, Indonesia, and offshore Cabinda, remote sensing, computer-aided drafting (CAD) and Global Positioning System (GPF) technologies have effectively been used by Chevron to provide accurate maps of facilities and to better understand environmental conditions. Together these proven technologies have provided a solid and cost-effective base for planning field operation, verifying well and seismic locations, and locating sampling sites. The end product of these technologies is often locations, and locating sampling sites. The end product of these technologies is often cartographic-quality hardcopy images and maps for use in the office and field. Chevron has been evaluating the capability of Geographical Information System (GIS) technology to integrate images, maps, and tabular data into a useful database that can help managers and workers better evaluate conditions in an oil field, plan new facilities, and monitor/predict trends (for example, of air emissions, groundwater, soil chemistry, subsidence, etc.). Remote sensing, CAD (if formatted properly), and GPS data can be integrated to establish the spatial or cartographic base of themore » GIS. A major obstacle to establishing a sophisticated GIS for an overseas operation is the initial cost of data collection and conversion from legacy data base management systems and hardcopy to appropriate digital format. However, Chevron routinely uses GIS for oil spill modeling and is now using GIS in the field for integrating GPS data with field observations and programs.« less

An optimization method for monitoring network design in multilayered groundwater flow systems

Multiple migration pathways and the need to consider several potential siting horizons render the problem of groundwater monitoring network design a difficult task for three‐dimensional systems. While the application of quantitative simulation‐based approaches for this problem is often impractical due to computational requirements, qualitative approaches can be ineffective because they are highly subjective and typically lack a set of well‐defined criteria for locating sampling sites. An analytically based methodology developed in this paper integrates the practical implementation aspects of a qualitative approach with a quantitative analysis in deriving groundwater monitoring networks geared toward early detection of migrating contaminant. Monitoring wells are located among sets of candidate nodes in each of several hydrostratigraphic intervals on the basis of contamination susceptibility. Susceptibility is defined by nodal weights, which are derived on the basis of the locations of sites relative to contaminant source boundaries and potential contaminant plumes. As is illustrated from the results of a case study application, derived monitoring network configurations exhibit two key characteristics: (1) clustering of wells around outlets at contaminant source boundaries and (2) coverage of vacant areas in multiple siting horizons that are susceptible to contamination.

Fish Assemblage Recovery Along a Riverine Disturbance Gradient

Artificial fluctuations in streamflow have been documented to alter the composition and structure of stream communities. This study tests the hypothesis that a spatial recovery gradient in fish assemblage structure exists downstream of a hydroelectric dam, and that recovery can be identified by the presence and abundance of species largely restricted to flowing-water habitats (fluvial specialists). A longitudinal gradient of change in a shoreline fish assemblage was quantified in a 66-km reach of a mid-sized, species-rich river (Tallapoosa River, Alabama) with daily flow fluctuations from hydropower generation. The shoreline fish assemblage in a nearby and similar river (Cahaba River, Alabama) was quantified as a regional reference for the occurrence of fish assemblage gradients. Fish were collected with prepositioned area electrofishers in 240 randomly located sampling sites, and physical habitat was quantified. Using distributional and habitat use information, fish species were categorized as fluvial specialists or macrohabitat generalists (species that occur in a wide variety of aquatic systems). Sampled habitats were similar between rivers and along each study reach. The longitudinal pattern of species occurrence and fish abundance was consistent in the free-flowing river. A longitudinal gradient of increasing abundance and richness of only fluvial specialist species existed downstream of the hydroelectric dam. No similar spatial gradient existed for macrohabitat generalists in either river. Although a fish community recovery gradient was identified, a recovery endpoint was not evident because assemblage change was gradual and possibly incomplete. The preservation and management of riverine fish faunas will partly depend on incorporating spatial recovery into decisions about permitting and siting of anthropogenic changes like hydroelectric dams.

Locating Sampling Sites for Salinity Mapping

AbstractAn evaluation of the suitability of a commercial long‐range navigation (LORAN‐C) method to locate and determine mapping coordinates of soil salinity sites was made in California field trials. The LORAN‐C‐determined position was within 16 m of the true position 90% of the time. This is sufficient accuracy to locate sampling areas identified with Système Probatoire d'Obervation de la Terre (SPOT) satellite imagery (pixel resolution of 30 m), but not for locating smaller sampling areas, such as those identified in low‐altitude photographs. The LORAN‐C method proved suitable for producing regional salinity maps that could resolve soil‐salinity differences on a scale of 200 m.

Gas exchange strategy in the Nile crocodile: a morphometric study

The respiratory surface area (SAR) per kilogram body mass (MB), the harmonic mean thickness of the air-blood barrier (τhtR) in the gas exchange tissue, and the anatomical diffusion factor (ADF=SAR/τhtR per MB) were calculated for four juvenile Nile crocodiles. The ADF of three small specimens (mean MB=3.59 kg) was 625 cm2·μm−1·kg−1. The values varied considerably among individuals and were similar to that of a 5.68-kg specimen (593 cm2·μm−1·kg−1). Only 9% of the ADF is located in the anterior third of the lung, which because of its conical shape makes up only 14 percent of the total lung volume. Particularly in the middle third of the lung, the proximal region near the intrapulmonary bronchus displays a greater ratio of respiratory/non-respiratory surface areas than do more distally located sampling sites. The τhtR is also significantly smaller proximally than distally. The cumulative ADF per unit MB is greater than that previously reported for this species on the basis of overall estimates of SAR and τhtR, but is still less than that of lizards and testudinids. The disposition of ADF between distal air storage region and the intrapulmonary bronchus is consistent with a bidirectional cross-current gas exchange model.

Radio Detector and Peg Technique for Locating Sampling Sites in the Field1

AbstractIt is usually difficult to relocate specific sites in fields. Many methods have been used, including metal detectors, permanent stakes and measuring from bench mark sites. A new system has been developed which has advantages over all these methods. It consists of a peg (transponder) that can be buried below cultivation depth and an easily operated detector that can detect the peg from approximately 2 m distance and home in on the exact position. The accuracy is within 5 cm when the peg is buried at a 1‐m depth. The equipment is of sturdy construction and the pegs remain useable for many years.