Terrestrial and Aquatic Ecology Commons^™

Leptodactylus Pentadactylus, Miriam M. Heyer, W. R. Heyer, Rafael O. De Sá

Biology Faculty Publications

Adult Leptodactylus pentadactylus (Figure 1) are large, the head is about as wide as long, and the hind limbs are moderately long (Table 1; Heyer and Thompson [2000] provided definitions of adult size and leg length categories for Leptodactylus). Male vocal sacs are not visible externally or are moderately expanded as a single sac. Sexually active males usually do not have hypertrophied forearms (the largest male examined, 195 mm SVL, has very weakly hypertrophied forearms), only the largest males have a single small to moderate size black spine on each thumb. No males have chest spines. Dorsolateral folds are …

The Impact Of Black Swan (Cygnus Atratus) Grazing On The Seagrass Halophila Ovalis In The Lower Swan River Estuary, Gary Choney

Theses: Doctorates and Masters

Grazing is an important ecosystem process, influencing community structure and rates of ecosystem processes. Although grazing on seagrasses is generally considered to be minor in many temperate regions of the world, waterfowl are often considered significant grazers in temperate lagoons and estuaries. This study examined spatial and temporal variation in swan abundance, grazing pressure and the impact grazing has on seagrass. Little is known on how grazing rates vary on larger water bodies in the southern hemisphere at different times of year and whether temporal changes in grazing rates affect the ability of seagrasses to tolerate grazing. The plant response …

Diversity And Community Assembly Patterns Of Epigean Vs. Troglobiont Spiders In The Iberian Peninsula, Pedro Cardoso

International Journal of Speleology

Cave-obligate organisms usually have smaller ranges and their assemblages have higher beta diversity than their epigean counterparts. Phylogenetic and functional diversity is usually low in cave communities, leading to taxonomic and functional disharmony, with entire groups missing from the subterranean realm. The objective of this work is to compare range, beta diversity, phylogenetic and functional diversity, taxonomic and functional disharmony of epigean versus troglobiont spiders in the Iberian Peninsula.

The median extent of occurrence was found to be 33 times higher for epigean than for cave species. Beta diversity was significantly higher for troglobiont assemblages. Cave assemblages present lower phylogenetic …

The World’S Deepest Subterranean Community - Krubera-Voronja Cave (Western Caucasus), Alberto Sendra, Ana Sofia P.S. Reboleira

International Journal of Speleology

Subsurface biota extends over a wide variety of habitats that can be spatially interconnected. The largest communities of this subsurface biota inhabit cavities and are well known mainly in caves where biologists are able to have access. Data about deep subterranean communities and arthropods living under one thousand meters was unknown.

An expedition to world’s deepest cave, Krubera-Voronja in Western Caucasus, revealed an interesting subterranean community, living below 2000 meters and represented by more than 12 species of arthropods, including several new species for science. This deep cave biota is composed of troglobionts and also epigean species, that can penetrate …

Ontogeny And Littoral Structure Of Lakes Created On Phosphate Mined Lands Of Central Florida, Chrysoula Mitraki

USF Tampa Graduate Theses and Dissertations

Created lakes are an end product of phosphate mining in Florida. Beginning in 1975, Florida reclamation rules set criteria for phosphate created lakes aiming to approximate the structure of natural lakes, and emphasizing extensive littoral zones with both emergent and submersed vegetation.

Lake development relative to lake age and design were examined for 22 phosphate lakes representing a 40-year age trajectory, utilizing water quality and benthic invertebrate communities from littoral and deep-water locations (Chapter 1). The relative importance of morphometry and lake age in the development of littoral plant communities was examined using multiple vegetation surveys throughout the year, in …

Diversity Among Macroalgae-Consuming Fishes On Coral Reefs: A Transcontinental Comparison, Adriana Verges, Scott Bennett, David R. Bellwood

Research outputs 2012

Despite high diversity and abundance of nominally herbivorous fishes on coral reefs, recent studies indicate that only a small subset of taxa are capable of removing dominant macroalgae once these become established. This limited functional redundancy highlights the potential vulnerability of coral reefs to disturbance and stresses the need to assess the functional role of individual species of herbivores. However, our knowledge of species-specific patterns in macroalgal consumption is limited geographically, and there is a need to determine the extent to which patterns observed in specific reefs can be generalised at larger spatial scales. In this study, video cameras were …

A Meta-Analysis Of Seaweed Impacts On Seagrasses: Generalities And Knowledge Gaps, Mads Thomsen, Thomas Wernberg, Aschwin H. Engelen, Fernando Tuya, Mat A. Vanderklift, Marianne Holmer, Karen J. Mcglathery, Francisco Arenas, Jonne Kotta, Brian R. Silliman

Research outputs 2012

Seagrasses are important habitat-formers and ecosystem engineers that are under threat from bloom-forming seaweeds. These seaweeds have been suggested to outcompete the seagrasses, particularly when facilitated by eutrophication, causing regime shifts where green meadows and clear waters are replaced with unstable sediments, turbid waters, hypoxia, and poor habitat conditions for fishes and invertebrates. Understanding the situations under which seaweeds impact seagrasses on local patch scales can help proactive management and prevent losses at greater scales. Here, we provide a quantitative review of available published manipulative experiments (all conducted at the patch-scale), to test which attributes of seaweeds and seagrasses (e.g., …

Limnological Assistance For Lake Mead National Recreation Area: Quarterly Report, Period Ending December 31, 2011, Margaret N. Rees

Limnological Studies

Project 1

• Technical assistance with the implementation of the Interagency Monitoring Action Plan (IMAP) for Quagga Mussels is ongoing; remaining analyses are underway with report delivery rescheduled for 05/2012.
• Data have been delivered for Veliger abundance and settlement at different depths of Lake Mead with report delivery re-scheduled for 05/2012.
• Growth of adult quagga mussels within Las Vegas Wash/Las Vegas Bay
• The Interagency Quagga Mussel Meeting was held on 11/17/2011; the next meeting is scheduled for 02/16/2011.

Project 2

• Appendix 7, an addition to the Long-term Limnological and Aquatic Resource Monitoring and Research Plan for Lakes Mead and Mohave, has …

Environmental Influences On Juvenile Fish Abundances In A River-Dominated Coastal System, Laure Carassou, Brian Dzwonkowski, Frank J. Hernandez, Jr., Sean P. Powers, William M. Graham, Kyeong Park, John Mareska

University Faculty and Staff Publications

We investigated the influence of climatic and environmental factors on variations in juvenile abundances of marine fishes in a river-dominated coastal system of the north-central Gulf of Mexico, where an elevated primary productivity sustains fisheries of high economic importance. Fish were collected monthly with an otter trawl at three stations near Mobile Bay from 1982 to 2007. Fish sizes were used to isolate juvenile stages within the data set, and monthly patterns in juvenile fish abundance and size were then used to identify seasonal peaks for each species. The average numbers of juvenile fish collected during these seasonal peaks in …

Avian Species Abundance In Response To Recreational Trail Use, Carrie A. Wencel

Department of Environmental Studies: Undergraduate Student Theses

Studies have indicated that non-consumptive outdoor recreation may affect wildlife. Thus, as the nation increases interest in outdoor recreation, data suggests the effect on wildlife will also increase. Previous studies indicate that as disturbance to wildlife increases, both avian species richness will decrease. Knowing how to anticipate effects on native species when planning and managing recreational areas is important in order to both provide for human desires and ensure the least impact to local species diversity.

The goal of this project was to observe and compare avian species richness and diversity between selected trail sites within Shevlin Park, Bend, Oregon …

Herpetofaunal Diversity At Yankee Hill State Lake And Wildlife Management Area, Lancaster County, Nebraska, Shelby Klima

Department of Environmental Studies: Undergraduate Student Theses

A survey for amphibians and reptiles was conducted in March through October 2011 at Yankee Hill Wildlife Management Area in Lancaster County, Nebraska. The survey was conducted using several different techniques including: visual and auditory encounters, artificial and natural cover objects, aquatic trappings and road surveys. A total of 145 individuals representing 12 species were identified including seven reptiles and five amphibians. A total of 48% of the species that may potentially occur on the site were encountered, all of which are common, widely distributed generalist species. Neither Graham’s Crayfish Snake nor the Massasauga, both target species for this survey, …

Synopsis Of Methods Used To Map Historical Vegetation In Oregon And Washington, Based On General Land Office Survey Notes, John Christy, Edward Alverson

Institute for Natural Resources Publications

Mapping historical vegetation in Oregon and Washington has been ongoing since about 1993. It is based primarily on General Land Office (GLO) surveyors' descriptions of vegetation, recorded between 1851 and about 1940. For areas along the coast and the lower Columbia River, topographic maps ("T-sheets") of the U.S. Coast Survey (later called U.S. Coast and Geodetic Survey, and more recently the National Geodetic Survey)—based on field work conducted between 1852 and 1889—have been integrated whenever possible with GLO data because of their superior cartography and land cover symbology. For more detailed descriptions of mapping methods, see Christy and Alverson (2011) …

Current Status And Long-Term Trends In Water Quality And Living Resources In The Virginia Tributaries And Chesapeake Bay Mainstem From 1985 Through 2010, Daniel M. Dauer, Harold G. Marshall, John R. Donat, Michael F. Lane, Suzanne C. Doughten, Frederick A. Hoffman, Raghavendra Kurada

Status and Trends for Virginia Chesapeake Bay

The period prior to the implementation of the Chesapeake Bay Monitoring Program was characterized by a marked decline in the water quality of the Chesapeake Bay. The disappearance of submerged aquatic vegetation in certain regions of the Bay, declines in the abundance of some commercially and recreationally important species, increases in the incidence of low dissolved oxygen events, changes in the Bay's food web, and other ecological problems have been related to the deteriorating water quality (e.g. USEPA, 1982,1983;Officer et al.,1984; Orth and Moore, 1984). The results of concentrated research efforts in the late 1970s and early 1980s stimulated the …

Preliminary Evaluations Of Secondary Productivity Estimates As Indicators Of The Ecological Value Of The Benthos To Higher Trophic Levels In Chesapeake Bay, Daniel M. Dauer, Michael F. Lane, Roberto J. Llansó, Robert Diaz

Benthic Applications

The primary objective of this project was to develop an analytical tool that management could use to assess the ecological value of the benthos for higher trophic levels. Ideally any tool developed should be simple to implement, adaptable to both fixed and probability monitoring programs and applicable across multiple spatial and temporal scales. Direct evaluations of secondary productivity involve time-consuming cohort or size-based methods that require multiple measurements of the populations in question over time (Dolbeth et al., 2005; Cusson and Bourget, 2005). However, empirical regression models have been developed that provide reasonable alternatives to these techniques when direct measurements …

Bryoecology In The American Southwest: Patterns Of Biodiversity And Responses To Global Change, John Carroll Brinda

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation combines investigation of the large-scale responses of bryophyte species diversity and distribution with small-scale physiological adaptations to global change. These two areas of inquiry are linked because one way to predict plant species responses to global change is to examine their distribution across current ecological gradients produced by factors such as latitude and elevation. By examining these biogeographic patterns one can identify those species that have a narrow tolerance and therefore are most sensitive to change. Selected bryophytes might then be used as indicator species in long-term monitoring programs. Where historical data exist, these can be used to …

Microbial Impacts On Endocrine Disrupting Contaminants: Las Vegas Wash And Lake Mead, Nevada, Susanna May Blunt

UNLV Theses, Dissertations, Professional Papers, and Capstones

International concern over endocrine disrupting chemicals (EDCs) has become heightened in recent years as more studies reveal their persistence in the environment and their detrimental effects on wildlife. However, little is known about the role of microorganisms in the fate and transport of these compounds in surface waters. Las Vegas Wash, a stream flowing into Lake Mead and fed primarily by treated wastewater effluent, provided a unique experimental system in which to study the role microorganisms play in the dispersal of these compounds in aquatic systems. Samples were collected from the Las Vegas Wash downstream of the Las Vegas Valley's …

Bycatch Of The Lake Pontchartrain Basin Inshore Shrimp Fishery And Its Effect On Two Sea Catfish Species: The Gafftopsail Catfish (Bagre Marinus) And The Hardhead Catfish (Ariopsis Felis), Scott P. Eustis

LSU New Orleans Theses and Dissertations

In Lake Pontchartrain Basin, commercial fishing in estuarine habitats impacts many non-target species collected as bycatch. I investigated the bycatch assemblages collected by commercial vessels and compared these to assemblages collected by typical fishery-independent methods. I compared assemblages using analysis of similarity (ANOSIM) and determined important species by weight and abundance using similarity percentages analyses (SIMPER). I also examined differences in size-class distributions by gear type using density kernel plots and Mann-Whitney U tests. The two gear types collected significantly different assemblages (ANOSIM R = 0.522, p = 0.001) and gear type explained more composition differences than other factors such …

A Comparison Of The Effectiveness Of Scent Lures On Attracting Mesopredators, Tom Batter

Department of Environmental Studies: Undergraduate Student Theses

A mesopredator is a medium-sized middle trophic level predator such as a raccoon (Procyon lotor), red fox (Vulpes vulpes), striped skunk (Mephitis mephitis), or coyote (Canis latrans; Crooks and Soule 1999). Mesopredators have long been trapped for recreational, economic, or academic reasons. Throughout human history trapping has been used to capture animals for food and skins, as well as to prevent personal harm and property damage from predators. In order to increase the probability of success, scent lures are often used as an attractant (Geary 1984, Mills et al. 2010, Schlexer 2008).

Prey Selection By The Northern Watersnake, Nerodia Sipedon, Kyle O' Connell

Department of Environmental Studies: Undergraduate Student Theses

Prey selection and composition of the northern waternake, Nerodia sipedon was investigated between 8/2010 and 3/2011 by palpation of stomach contents in the field and conducting laboratory trials. 41 snakes were captured, five yielded prey contents. Fish parts, freshwater mussels, and an insect exoskeleton were found. No amphibians were found despite availability at study sites. Snakes in the laboratory underwent 22 trials, feeding on 11 occasions. Snakes fed on an equal number of both fish species, revealing no selection. Further research is needed to determine the rate of digestion of N. sipedon.

Effects Of Climate Change On Spring Ecosystem Hydroecology As A Guide To Developing Alternative Water Policies, Scott Mensing, Saxon E. Sharpe, Scott Bassett, Don Sada, Jim Thomas

Climate Change Seminar Series (NNE)

Hydroecology: the interface of ecological systems and water which combines the scientific disciplines of hydrology and ecology

Goal: evaluate the hydrologic and climate history using pollen, loss on ignition, total inorganic carbon, and invertebrates from spring sediments in Spring Valley, Eastern Nevada and Snake Valley, Western Utah