News from Scientists at the USGS Patuxent Wildlife Research Center
Tuesday, October 15, 2002
| Patuxent's
Mcdiarmid Presents Paper with Colleagues at the ICSEB Meeting in
Greece
Patuxent Scientist, Dr. Roy McDiarmid recently presented the following paper with two colleagues at the ICSEB meeting in Greece: Ruggiero, M., R.W. McDiarmid and B.B. Collette. 2002. Organizing the names: the ITIS experience. Presentation in Symposium 10, A Diversity of Names for the Diversity of Life, at the Sixth International Congress of Systematic and Evolutionary Biology (ICSEB VI), held from 9-16 September 2002, in Patras, Greece. Abstract: The Integrated Taxonomic Information System (ITIS) is a database of scientific and vernacular names of organisms arranged in a hierarchy. ITIS includes all taxa but primarily those from North America and surrounding waters. ITIS began in 1993 and went on line in 1996. Currently there are nearly 400,000 names in the system. We present an overview of what ITIS is, how it started, sources of the original data, and its growth through collaboration with systematists and other list keepers. ITIS recently expanded to include Canada and Mexico as partners (ITIS NA), and has an international collaboration with Species 2000 and GBIF. We also discuss some of the lessons learned during the 10 year life of the project, specifically, (1) advantages and disadvantages of a global vs. a regional approach; (2) a single accepted list of names vs. multiple classification; (3) competing issues of data quality vs. data quantity (4) making ITIS useful to systematists, resource managers, and decision-makers. Contact: Dr Roy W. McDiarmid 202.357.2780 Patuxent Scientist Sykes Presents Poster Entitled "An Efficient Method of Capturing Painted Buntings and Other Small Seed-Eating Passerines" at Third North American Ornithological Conference Patuxent Scientist, Paul W. Sykes recently present a poster entitled: An efficient method of capturing Painted Buntings and other small seed-eating passerines at the Third North American Ornithological Conference in New Orleans, LA on 25 September and again at the Georgia Ornithological Society fall meeting at Jekyll Island, GA on 5 October. The poster dealt with the development of a technique to capture a large sample of buntings for uniquely color leg banding as part of a six-year study of "Annual survival in the southeastern coastal breeding population of the Painted Bunting" (P. W. Sykes, Jr., W. L. Kendall, and J. M. Meyers). At the completion of the fourth field season, 2667 individuals had been captured, banded and released in four states (FL, GA, SC, and NC) using the technique described. Contact: Paul W. Sykes 706-542-1237 Publications by Patuxent Scientists: Albers Publishes Article Entitled "Source, fate, and effects of PAHs in shallow water environments: a review with special reference to small watercraft" Albers, P. H. 2002. Sources, fate, and effects of PAHs in shallow water environments: a review with special reference to small watercraft. Pages 143-150 in Michael J. Kennish, editor. Impacts of Motorized Watercraft on Shallow Estuarine and Coastal Marine Environments. Journal of Coastal Research Special Issue 37 Abstract: Polycyclic aromatic hydrocarbons (PAHs) are aromatic hydrocarbons with two to seven fused carbon (benzene) rings that can have substituted groups attached. Shallow coastal, estuarine, lake, and river environments receive PAHs from treated wastewater, stormwater runoff, petroleum spills and natural seeps, recreational and commercial boats, natural fires, volcanoes, and atmospheric deposition of combustion products. Abiotic degradation of PAHs is caused by photooxidation, photolysis in water, and chemical oxidation. Many aquatic microbes, plants, and animals can metabolize and excrete ingested PAHs; accumulation is associated with poor metabolic capabilities, high lipid content, and activity patterns or distributions that coincide with high concentrations of PAHs. Resistance to biological transformation increases with increasing number of carbon rings. Four- to seven-ring PAHs are the most difficult to metabolize and the most likely to accumulate in sediments. Disturbance by boating activity of sediments, shorelines, and the surface microlayer of water causes water column re-entry of recently deposited or concentrated PAHs. Residence time for PAHs in undisturbed sediment exceeds several decades. Toxicity of PAHs causes lethal and sublethal effects in plants and animals, whereas some substituted PAHs and metabolites of some PAHs cause mutations, developmental malformations, tumors, and cancer. Environmental concentrations of PAHs in water are usually several orders of magnitude below levels that are acutely toxic, but concentrations can be much higher in sediment. The best evidence for a link between environmental PAHs and induction of cancerous neoplasms is for demersal fish in areas with high concentrations of PAHs in the sediment. Contact: Dr Peter H. Albers 301-497-5700 Winger Publishes Article Entitled "Toxicological assessment of aquatic ecosystems: application to watercraft contaminants in shallow water environments" Winger, P. V. 2002. Toxicological assessment of aquatic ecosystems: application to watercraft contaminants in shallow water environments. Pages 179-191 in Michael J. Kemmish, editor. Impacts of Motorized Watercraft on Shallow Estuarine and Coastal Marine Environments. Journal of Coastal Research Special Issue 37 Abstract: Recreational boating and personal watercraft use have the potential to adversely impact shallow water systems through contaminant release and physical disturbance of bottom sediments. These nearshore areas are often already degraded by surface runoff, municipal and industrial effluents, and other anthropogenic activities. For proper management, information is needed on the level of contamination and environmental quality of these systems. A number of field and laboratory procedures can be used to provide this much needed information. Contaminants, such as metals, pesticides, polychlorinated biphenyls and polycyclic aromatic hydrocarbons, entering aquatic environments generally attach to particulate matter that eventually settles and becomes incorporated into the bottom sediments. Because bottom sediments serve as a sink and as a source for contaminants, environmental assessments generally focus on this matrix. While contaminant residues in sediments and sediment pore waters can reflect environmental quality, characteristics of sediment (redox potential, sediment/pore-water chemistry, acid volatile sulfides, percent organic matter, and sediment particle size) influence their bioavailability and make interpretation of environmental significance difficult. Comparisons of contaminant concentrations in pore water (interstitial water) and sediment with water quality criteria and sediment quality guidelines, respectively, can provide insight into potential biological effects. Laboratory bioaccumulation studies and residue concentrations in resident or caged biota also yield information on potential biological impacts. The usefulness of these measurements may increase as data are developed relating in-situ concentrations, tissue residue levels, and biological responses. Exposure of test organisms in situ or to field-collected sediment and pore water are additional procedures that can be used to assess the biological effects of contaminants. A battery of tests using multi-species and/or various life stages with different sensitivities to contaminants may offer a more conservative assessment of toxicity than single species testing. Using a "weight of evidence" approach, the Sediment Quality Trial produces a robust evaluation of habitat quality and includes a measure of contaminant concentrations in the sediment, an assessment of sediment/pore-water toxicity to laboratory animals, and an evaluation of in situ biological assemblages. Field and laboratory procedures are available that can be used to ascertain habitat quality, identify contaminants causing environmental degradation and delineate aquatic systems requiring mitigation of protective efforts. These studies provide the scientific data that are integral to developing an environmental risk assessment of contaminants from watercraft use in shallow water systems. Contact: Dr Parley V. Winger 706-546-2146 |
Publications, continued Guntenspergen Among Authors of Article Entitled "Narrowing historical uncertainty: probabilistic classification of ambiguously identified tree species in historical forest survey data". Mladenoff, D. J., S. E. Dahir, E. V. Nordheim, L. A. Schulte, and G. G. Guntenspergen. 2002. Narrowing historical uncertainty: probabilistic classification of ambiguously identified tree species in historical forest survey data. Ecosystems 5:539-553. Abstract: Historical data have increasingly become appreciated for insight into the past conditions of ecosystems. Uses of such data include assessing the extent of ecosystem change; deriving ecological baselines for management, restoration, and modeling; and assessing the importance of past conditions on the composition and function of current systems. One historical data set of this type is the Public Land Survey (PLS) of the United States General Land Office, which contains data on multiple tree species, sizes, and distances recorded at each survey point, located at half-mile (0.8 km) intervals on a 1-mi (1.6 km) grid. This survey method was begun in the 1790s on US federal lands extending westward from Ohio. Thus, the data have the potential of providing a view of much of the US landscape from the mid-1800s, and they have been used extensively for this purpose. However, historical data sources, such as those describing the species composition of forests, can often be limited in the detail recorded and the reliability of the data, since the information was often not originally recorded for ecological purposes. Forest trees are sometimes recorded ambiguously, using generic or obscure common names. For the PLS data of northern Wisconsin, USA, we developed a method to classify ambiguously identified tree species using logistic regression analysis, using data on trees that were clearly identified to species and a set of independent predictor variables to build the models. The models were first created on partial data sets for each species and then tested for fit against the remaining data. Validations were conducted using repeated, random subsets of the data. Model prediction accuracy ranged from 81% to 96% in differentiating congeneric species among oak, pine, ash, maple, birch, and elm. Major predictor variables were tree size, associated species, landscape classes indicative of soil type, and spatial location within the study region. Results help to clarify ambiguities formerly present in maps of historic ecosystems for the region and can be applied to PLS datasets elsewhere, as well as other sources of ambiguous historical data. Mapping the newly classified data with ecological land units provides additional information on the distribution, abundance, and associations of tree species, as well as their relationships to environmental gradients before the industrial period, and clarifies the identities of species formerly mapped only to genus. We offer some caveats on the appropriate use of data derived in this way, as well as describing their potential. Contact: Dr Glenn G. Guntenspergen 301-497-5523 Patuxent Scientists Jung, Sauer and Droege Among Authors of "An evaluation of population index and estimation techniques for tadpoles in desert pools" Jung, R. E., G. H. Dayton, S. J. Williamson, J. R. Sauer, and S. Droege. 2002. An evaluation of population index and estimation techniques for tadpoles in desert pools. Journal of Herpetology 36(3):465-472. Abstract: Using visual (VI) and dip net indices (DI) and double-observer (DOE), removal (RE), and neutral red dye capture-recapture (CRE) estimates, we counted, estimated, and censused Couch's spadefoot (Scaphiopus couchii) and canyon treefrog (Hyla arenicolor) tadpole populations in Big Bend National Park, Texas. Initial dye experiments helped us determine appropriate dye concentrations and exposure times to use in mesocosm and field trials. The mesocosm study revealed higher tadpole detection rates, more accurate population estimates, and lower coefficients of variation among pools compared to those from the field study. In both mesocosm and field studies, CRE was the best method for estimating tadpole populations, followed by DOE and RE. In the field, RE, DI, and VI often underestimated populations in pools with higher tadpole numbers. DI improved with increased sampling. Larger pools supported larger tadpole populations, and tadpole detection rates in general decreased with increasing pool volume and surface area. Hence, pool size influenced bias in tadpole sampling. Across all techniques, tadpole detection rates differed among pools, indicating that sampling bias was inherent and techniques did not consistently sample the same proportion of tadpoles in each pool Estimating bias (i.e, calculating detection rates) therefore was essential in assessing tadpole abundance. Unlike VI and DOE, DI, RE, and CRE could be used in turbid waters in which tadpoles are not visible. The tadpole population estimates we used accommodated differences in detection probabilities in simple desert pool environments but may not work in more complex habitats. Contact: Dr Robin E. Jung Jung and Droege Among Authors of "Evaluation of canoe surveys for anurans along the Rio Grande in Big Bend National Park, Texas" Jung, R. E., K. E. Bonine, M. L. Rosenshield, A. de la Reza, S. Raimondo, and S. Droege. 2002. Evaluation of canoe surveys for anurans along the Rio Grande in Big Bend National Park, Texas. Journal of Herpetology 36(3):390-397. Abstract: Surveys for amphibians along large rivers pose monitoring and sampling problems. We used canoes at night to spotlight and listen for anurans along four stretches of the Rio Grande in Big Bend National Park, Texas, in 1998 and 1999. We explored temporal and spatial variation in amphibian counts and species richness and assessed relationships between amphibian counts and environmental variables, as well as amphibian-habitat associations along the banks of the Rio Grande. We documented seven anuran species, but Rio Grande leopard frogs (Rana berlandieri) accounted for 96% of the visual counts. Chorus surveys along the river detected similar or fewer numbers of species, but orders of magnitude fewer individuals compared to visual surveys. The number of species varied on average by 37% across monthly and nightly surveys. We found similar average coefficients of variation in counts of Rio Grande leopard frogs on monthly and nightly bases (CVs = 42-44%), suggesting that canoe surveys are a fairly precise technique for counts of this species. Numbers of Rio Grande leopard frogs observed were influenced by river gage levels and air and water temperatures, suggesting that surveys should be conducted under certain environmental conditions to maximize counts and maintain consistency. We found significant differences in species richness and bullfrog (Rana catesbeiana) counts among the four river stretches. Four rare anuran species were found along certain stretches but not others, which could represent either sampling error or unmeasured environmental or habitat differences among the river stretches. We found a greater association of Rio Grande leopard frogs with mud banks compared to rock or cliff (canyon) areas and with seepwillow and open areas compared to giant reed and other vegetation types. Canoe surveys appear to be a useful survey technique for anurans along the Rio Grande and may work for other large river systems as well. Contact: Dr Robin E. Jung 301-497-5875 Patuxent's Sykes Presented with Earle R. Greene Memorial Award for Outstanding Achievement in Ornithology On 5 October, Patuxent Scientist Paul W. Sykes was presented the Earle R. Greene Memorial Award by the Georgia Ornithological Society at the fall meeting at Jekyll Island, GA. This annual award is presented for outstanding achievement in ornithology. Previous recipients include Chan Robbins, Roger Tory Peterson, Ron Pulliam, Eugene Odum, John Avise, et al. Contact: Paul W. Sykes 706-542-1237
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