12/2012 - Michael McCann, Stony Brook University, USA
Regime shifts are abrupt transitions between distinct community and ecosystem states. They are found in many ecological systems and are typically depicted as a large change in dominance between species or functional groups in response to a small change in an environmental driver. Many small, freshwater ponds can be found in distinct states – dominated by unrooted, floating plants (e.g., duckweed), by submerged vegetation, or by phytoplankton and each with very different ecosystem properties. The shift between these regimes is mainly driven by changes in nutrient levels, often from anthropogenic sources. Small ponds such as these are an ideal system for studying the characteristics of ecological system that make them prone to a regime shift – in particular how species-, community-, and ecosystem-level properties can modify the functional relationship between an environmental driver (e.g., nutrients such as nitrogen and phosphorus) and system state (e.g., growth form of the dominant vegetation). My dissertation will use a multilevel approach in freshwater ponds to understand the presence and likelihood of a regime shift to floating plant dominance in waterbodies on Long Island, New York and Connecticut. I am surveying many small ponds in Long Island and Connecticut to document the abundance and composition of aquatic primary producer growth forms (i.e., free-floating, submerged, or phytoplankton) and I am relating the vegetation regimes to abiotic factors (e.g., nutrients, pH) and waterbody characteristics (e.g., surface area). I am also conducting laboratory experiments to examine growth rates, nutrient uptake rates, and competitive interactions between different species of free-floating plants over a range of nutrient conditions.
07/2012 - Natasha Gownaris, Stony Brook University, USA
My dissertation research focuses on understanding how changes in the flow rates of the Omo River, Ethiopia will impact the fish communities of Lake Turkana, Kenya. Lake Turkana is the world's largest desert lake and the most understudied of the African Great Lakes. It is home to 50 species of fish, the world's largest remaining Nile Crocodile population, and 350+ native and migratory bird species. Over 700,000 people from eight tribes live on the lake's shores and depend on it for food, water, and transportation. The Omo River contributes 90% of the lake's inflow. Changes in Omo River inflow are expected to occur due to climate change, dam development (e.g. Gibe III), and large-scale irrigation schemes in the region. Changes in the patterns of Omo River inflow will alter the turbidity, productivity, salinity, and the availability of important fish habitats in the lake. I hope to determine the current movement patterns of the lake's fishes and the trophic structure of different fish communities in the lake and how these parameters will be impacted by changes in water inflow. I will also be using geographic information systems to determine how different water inflow scenarios will alter habitat availability. The end goal of this project will be to develop an ecological model that will be used to predict changes in fish communities (e.g. species dominance, biomass, fisheries productivity) given different water inflow scenarios.
12/2011 - Lesley Knoll, Lacawac Sanctuary Foundation, USA
Lake Lacawac is a pristine glacial lake located in Northeastern Pennsylvania. I plan to use Lake Lacawac as a "control" or "model" lake in which to study the effects of climate change on lake ecosystems. The watershed of this lake has been well-protected and generally unimpacted by human disturbance. Common issues associated with human development/modification, such as eutrophication, are not a confounding factor in this lake. I will use Lake Lacawac, nearby impacted lakes, and experiments to determine the effects of altered precipitation patterns and temperature on lake ecosystems.
07/2011 - Andrew Chang, University of California @ Davis, USA
My research has two parts. One is to examine the mechanisms by which ecological communities are assembled and the ultimate consequences of different assembly histories for the structure and functioning of communities. How estuarine community structure and functioning affected by the history of species arrival and the timing of disturbances such as storms and freshwater flow (which is directly tied to both watershed modification and climate change)? This work is done using sessile estuarine invertebrates such as bivalves, tunicates, bryozoans, and so on, in the San Francisco Estuary. I use long term surveys, monitoring of temperature and salinity, and manipulative experiments to understand community dynamics (part 1). One significant aspect of this work is that I have shown very large community changes that are tied to freshwater flow changes -- and now I aim to determine the effects of these changes for the broader ecosystem, especially through changes in the community's water filtration activity.
The second part of my research examines native Olympia oyster (Ostrea lurida) population dynamics, their responses to storm events, and functional consequences for the ecosystem. Olympia oysters are one of the few native Pacific coast estuarine species, are considered a foundation species for these estuarine ecosystems, and are currently a target of significant restoration efforts. Yet relatively little is known about the factors that govern oyster population dynamics in Pacific estuaries or about their effect on algae and plankton in the water column in different salinity, temperature, and turbidity conditions. This knowledge is crucial both to more effective conservation and restoration efforts as well as understanding the likely effects of climate change on these ecosystems. This work involves long-term monitoring and surveys, trace element microchemistry (to track dispersal of oyster larvae), and manipulative experiments.
12/2010 - Don Buso, Cary Institute of Ecosystem Studies, USA
I manage research projects for the Cary Institute (in NY) at the Hubbard Brook Experimental Forest (HBEF) in NH (www.hubbardbrook.org
). Previous research at HBEF has revealed that Dissolved Organic Carbon in streams varies across the landscape in patterns that can be correlated to several characteristics, such as differences in vegetation cover type, the presence of wetlands, and stream geomorphology. The variability in DOC influences many in-stream metabolic processes, acid-base reactions, and watershed carbon export. Documenting that variablity spatially is critical to understanding the importance of each characteristic.
07/2010 - Denise Burchsted, University of Connecticut, USA
My research addresses the fundamental question of the billion-dollar river restoration industry: what did our rivers look like prior to European colonization? Typically, river restoration projects are designed according to a vision of unobstructed, free-flowing waterbodies. Pre-industrial rivers, however, were punctuated by frequent obstructions of many types. These obstructions included those created by beavers who construct up to three dams in a 100-meter stretch of river.
Although beavers once dominated headwaters and floodplains across the continental United States, as demonstrated by fur trading records, historic accounts, and sediment cores, fur trapping nearly exterminated them from the U.S. Successful reintroduction in protected areas enables researchers to characterize beaver-colonized landscapes. However, the extent of modification under beavers is so great that reintroduction is infeasible for many rivers targeted for restoration. Therefore, my PhD research quantifies the hydrology, sediment regime, and shape of beaver-colonized headwater streams in order to apply these parameters to river restoration design in the human environment.
12/2009 - Jeffrey Simmons, Mount St. Mary's University, USA
My students and I are investigating the impacts of wastewater effluent on stream ecosystems. Much is known about eutrophication of lakes and estuaries, but much less has been reported about the impacts on streams themselves. Our goal is to determine the changes in ecosystem function in streams. We have so far focused on decomposition and effects on phosphorus cycling. Next we would like to begin to investigate the impacts on algal biomass (periphyton and planktonic) and productivity. Nutrient concentrations are higher downstream of wastewater treatment plants, so we expect algal biomass and productivity to be higher. But the question is, how much higher? Will biomass stay the same due to increased grazing? Will light limitation restrict the amount of production?
07/2009 - Nancy Dalman, North Georgia College and State University, USA
The focus of my research recently has been water quality in the native waters of North Georgia. I currently have two research projects and a community outreach program that encompass water quality issues:
1. The first project, one that has been ongoing since 2007, examines the impact of human recreation on fecal bacteria counts. The premise for this work is that river sediments harbor high fecal coliform bacteria counts and that humans entering the river disrupt these bacterial stores, amplify waterborne bacteria counts and increase their risk of illness. This spring, we published a paper with data supporting this hypothesis. Work was done in a stretch of mountain river that receives several hundred people rafting and tubing each day. Our results showed that water samples collected in the evening, near the end of the daily human activity period, contained high levels of sediment within the water column and showed significantly greater E. coli counts than water samples collected in the morning prior to humans entering the water. This trend was only apparent at high traffic sites. We plan to focus our work this summer on identifying the host source of bacteria; measurement of optical brighteners in the water will act as a screening method in this process. The area surrounding this river contains several cattle ranches, poultry farms and houses with septic systems, all of which are possible sources of contamination. Measurement of optical brighteners will distinguish human host from other host sources.
2. The second research project will be initiated this summer in conjunction with biology and physics colleagues. This large - scale study will encompass three watersheds to examine landscape influences on water quality. Similar work has been done in other watersheds; the unique aspect of our work is the clear gradient of human development across these three watersheds. Our plan is to conduct a multi - year study that investigates different land uses and changes in these uses over time on three physically similar watersheds. Water quality (including basic chemical and physical parameters, fecal bacteria counts, Indices of Biotic Integrity, cyanobacteria measurements) will provide a cornerstone to the project, but we hope to extend our collaboration in the future and incorporate measures of human community health and socioeconomic factors.
3. This past fall several biology colleagues and I began an annual community - wide watershed monitoring event. This event, the River Rendezvous, involved college students and community volunteers in conducting a one - day "snapshot" of water quality throughout our county's watershed. The data gathered is currently being used in follow - up bacterial source tracking at sampling locations with high bacterial counts. By making this an annual event, we will be able to collect long - term data that may track changes in water quality, foster interaction between the university and local region and give community members stewardship of our county's rivers.
12/2008 - Marita Davison, UMSA & BIOTA, Bolivia; Cornell Lab of Ornithology, USA
Of the six extant species of flamingo in the world, those restricted to wetlands of the high Andes of Argentina, Bolivia, Chile and Peru (Andean flamingo, Phoenicoparrus andinus and James flamingo, P. jamesi) are the most endangered and least studied. As dominant grazers on phytoplankton in their habitats, flamingos play a focal role in aquatic food webs by influencing primary production, nutrient cycling, and species diversity. Two of the most important breeding and feeding sites for Andean and James flamingos across their range, Laguna Colorada and Lago Uru-Uru/Poopo, are located in southwestern Bolivia. Although both of these wetland systems are RAMSAR wetland conservation sites, flamingo populations are declining in both areas as a result of intense human disturbance in the form of unregulated ecotourism (Laguna Colorada) and sewage pollution (Lago Uru-Uru/Poopo). The aim of this research is to combine experimental and monitoring approaches to investigate the influence of pollution and human-induced flamingo loss on biomass of primary producers and lake biodiversity at Laguna Colorada and Lago Uru-Uru/Poopo. Scientific data on the ecological role of flamingos within a context of human disturbance will be directly relevant for promoting sound conservation strategies for these endangered birds and the unique ecological systems of which they are a part.
07/2008 - John Spinicchia- St. Mary's County, Maryland Public Schools, Leonardtown, MD
We are currently monitoring one of the sites on Breton Bay, a tidal tributary of the Chesapeake Bay. Breton Bay is currently listed as impaired under EPA CWA section 303 (d). Breton Bay serves Leonardtown, St. Mary's County seat; The St. Mary's County Waste Water Treatment Plant dumps over 1 million gallons of treated waste per day into a tributary of Breton Bay. We need to monitor for eutrophication as indicated by chlorophyll a in vivo
concentrations on a monthly basis and submit the data to the Maryland Department of the Environment/ Department of Natural Resources. The long term loaner instrument we were using was recently taken back by Morgan State University. We do not have the money in our budget to buy an instrument; this is a public school.
The instrument will allow us to monitor Chl a
concentrations and to prepare our yearly report by comparing our data to the other monitoring stations and to the determined TMDL for Chl a
. We can also look at turbidity and correlate to the amount of farmland/runoff and application and effectiveness of agricultural and development BMP's.
Update from 06/03/10 "We are using the Aqua
Fluor to track chlorophyll a
as a function of season and events in order to get a rough estimate of food availability for an oyster restoration project we are participating in. The study also involves O2 availability, pH, and the usual water quality parameters. Samples are taken every two weeks and the Aqua
Fluor has been a great tool for educating prospective professionals in the natural resources management fields. We really appreciate the grant and the opportunity to use this instrument."
12/2007 - Laurel Standley - Silent Springs Institute, Newton, MA
The primary barrier to our goal of systematically screening adequate numbers of water samples for endocrine disrupting compounds (EDCs) and pharmaceuticals is expense, with analysis for each sample costing approximately $1,000. To guide our selection of water samples, we must often use indirect measures of potential contamination, including land use designations, such as residential density, and/or the presence of other wastewater contaminants, such as nutrients. These approaches are helpful but limited. The best proxies for EDCs and pharmaceuticals, beyond incurring the cost of measuring them directly, are compounds in wastewater that behave similarly in ground and surface waters. Fluorescent whitening agents (FWAs), which are added to clothes, detergents, and paper products to brighten their appearance, fit these characteristics; thus, we propose to use them as proxies for EDCs and pharmaceuticals in ground and surface waters. Use of a fluorometer to screen for the presence of wastewater-associated FWAs would greatly streamline sample screening and allow us to more accurately select samples to submit to a laboratory for the more costly analysis of EDCs and pharmaceuticals. For example, on a recent sampling trip a colleague used his fluorometer to pinpoint the location of wastewater plumes to ponds, greatly facilitating our sampling efforts. With a donation of your company's fluorometer, we would have this screening capability available for all our projects.
Update from 06/05/08 "We are using the Aqua
Fluor Fluorometer to develop a screening method for evidence of wastewater contamination in drinking water, ground water, and surface water samples. We have begun testing tap water samples for the presence of optical brighteners and comparing them to water that has been treated using commercially-available carbon filters. In addition to these experiments, we are also getting ready to sample ponds that receive wastewater-contaminated groundwater for the presence of optical brighteners. The instrument is very easy to use and we appreciate the donation which has enabled us to move forward with this project."
07/2007 - Dr. Johan van der Molen- University of KwaZulu-Natal, South Africa , South Africa
The St. Lucia lake system is the largest estuarine system in Africa with a water surface of 300 km2 and a shoreline of over 400 km. However, the mouth of this estuary has been closed between July 2002 and March 2007. This has had a major impact on the entire ecosystem. Although the estuary is a World Heritage site, very little research has been undertaken on the lower levels of the food web. Indeed, the algae of the St. Lucia system have received little attention from researchers concerning their biomass and especially their productivity. Phytoplankton productivity in estuaries plays an essential role in element cycling, water quality, and food supply to heterotrophs. The aim of this study is to provide quantitative data of biomass and productivity for phytoplankton and microphytobenthos and to analyse the correlation with biotic and abiotic parameters.