Terrestrial and Aquatic Ecology Commons^™

An Investigation Of Epiphytic Diatom Substrate Specificity And Its Use In Paleolimnology, David Rawn Zilkey

Electronic Thesis and Dissertation Repository

Submerged macrophyte communities are an important component of lake ecosystems that can be altered by anthropogenic disturbances. In the absence of direct monitoring, it is difficult to know how these communities respond to such disturbance. This thesis investigated the potential of epiphytic diatoms preserved in lake sediments to record submerged macrophyte community composition. Epiphytic diatoms from Chara sp., Myriophyllum spicatum and Potamogeton robbinsii were sampled from Gilmour Bay, Ontario, Canada to assess whether submerged macrophyte species were characterized by distinct diatom communities. Principal components analysis indicated overlap, but analysis of similarity suggested there were differences in diatom community composition. A …

Developing A Long-Term Perspective On The Sensitivity Of Lake Trophic State Changes In Maine, Simona Lukasik

Electronic Theses and Dissertations

Even with similar external drivers, lakes can respond differently because of key ecosystem features that determine lake sensitivity. Identifying factors that determine lake sensitivity are important for successful lake management. The purpose of this research was to determine patterns of algal community change over the past 400 years in lakes with watersheds that vary in surficial geology, specifically the glacio-marine clay layer in Maine known as the Presumpscot formation. Responses to two external drivers, major land use changes and climate change, were assessed. Four lakes were chosen based on their surficial geology and land use history: Unity Pond, Webber Pond, …

Diatom Voucher Flora And Comparison Of Collection Methods For Biodiversity Hotspot Upper Three Runs Creek, Katie M. Johnson

Biology Theses

Surface freshwater is a scarce resource. Due to the scarcity and necessity of this resource, it is imperative that its quality is routinely monitored. One way of monitoring water quality is through biological assessments, which include examining algal assemblages. Regionally, little remains known of algal taxa in the southeastern United States. In the past, the Academy of Natural Sciences of Philadelphia (ANSP) conducted biological assessments along the Savannah River finding Gomphonema parvulum (Kützing) Kützing 1849 to be a dominant taxon rendering assessments inconclusive. Recent studies have provided evidence that species complexes and semi-cryptic taxa have been identified within the Gomphonema …

Assessing The Hierarchy Of Long-Term Environmental Controls On Diatom Communities Of Yellowstone National Park Using Lacustrine Sediment Records, Victoria Chraibi, Sherilyn C. Fritz

Department of Earth and Atmospheric Sciences: Faculty Publications

An ecosystem’s ability to maintain structure and function following disturbance, defined as resilience, is influenced by a hierarchy of environmental controls, including climate, surface cover, and ecological relationships that shape biological community composition and productivity. This study examined lacustrine sediment records of naturally fishless lakes in Yellowstone National Park to reconstruct the response of aquatic communities to climate and trophic cascades from fish stocking. Sediment records of diatom algae did not exhibit a distinct response to fish stocking in terms of assemblage or algal productivity. Instead, 3 of 4 lakes underwent a shift to dominance by benthic diatom species from …

Assessing The Mechanisms And Implications Of Altered Carbon Cycling In Arctic And Boreal Lakes, Rachel Fowler

Electronic Theses and Dissertations

Dissolved organic carbon (DOC) is an important component of lake ecology, as it contributes to light attenuation and carbon cycling. In recent years, DOC declined in a suite of lakes in Greenland. I performed experiments to test potential mechanisms of DOC loss. The tested mechanisms did not reduce DOC concentration, but DOC composition was affected. I also paired water quality data with meteorological observations to evaluate effects of climate drivers on lake variables. The lake variables were temporally coherent and associated with patterns of mean annual precipitation.

In the northeastern U.S., recovery from acidification and climate change have contributed to …

Impacts Of River Influence And Wave Exposure On The Epipsammic Diatoms Of The Lake Superior Wave Zone, Leon R. Katona

All NMU Master's Theses

Although little is known about primary productivity in wave zone habitats of very large lakes, it is presumably dominated by microalgae that attach to mineral substrates. Watershed energetics are linked with these wave zones through river mouth habitats, which provide nutrient and organismal input to lake systems. In this study, I assessed the abundance, productivity, and community composition of epipsammic diatoms in river mouth and beach habitats along the south-central coast of Lake Superior. Chlorophyll a concentrations were more than three-fold greater in river mouths (mean ± 1SE = 1.17 ± 0.45 mg/m²), than in wave zone (0.36 …

Evaluation Of Temperature Anomalies And Ocean Productivity During The 2004 Sumatra-Andaman Earthquake, Cora Byers, Brenna Mcnabb

Student Scholar Symposium Abstracts and Posters

The oceanic productivity of the Indian Ocean and temperature anomalies prior to the Sumatra-Andaman earthquake (MW =9.3) and tsunami (December 26th 2004) were studied. Data was obtained via NASA’s Giovanni program to determine the effect on phytoplankton (primary producers) and temperature changes over the region of the earthquake. Seasonal trends were visible in the concentrations of chlorophyll a, coccolithophores, cyanobacteria, chlorophytes, diatoms and absorption coefficient, in addition to storm trends.

Ecohydraulic Investigation Of Diatoms In A Bedrock-Controlled Stream, Alex M. Rittle

Theses and Dissertations--Geography

Recent studies within the past decade or so have shown the importance of algae in geomorphic and hydrologic processes of lotic systems. However, the ecohydraulic role of algae in bedrock systems has largely been ignored. In addition, the utility of algae as indicators of channel dynamics have often been assumed by geomorphologists, but relatively few studies have examined this relationship. The purpose of this study was to determine whether algae, specifically diatoms, are useful indicators of channel geomorphological dynamics, and to examine if distinct habitats or biotopes typical in fluviokarst and bedrock systems provide unique habitat space for diatoms, and …

How The Presence Of Plastic In The North Pacific Gyre Affects The Growth Of Thalassiosira Through Remote Sensing And Laboratory Replication, Jordynn Brennan, Hesham El-Askary

Student Scholar Symposium Abstracts and Posters

Through the use of remote sensing, we are able to determine the approximate location of the garbage patch in the North Pacific Gyre. Though remote sensing does not penetrate the surface of the ocean, monthly satellite images can be analyzed to determine the rate of growth or rate of decrease of certain parameters, such as atmospheric gases, phytoplankton, and dissolved organic matter. Over the past decade, data from the Goddard Earth Sciences Data and Information Services Center (Giovanni program) has shown a significant increase in dissolved organic matter and chlorophyll a content in the area of the North Pacific Garbage …

Evidence Of Climate Variability And Tropical Cyclone Activity From Diatom Assemblage Dynamics In Coastal Southwest Florida, Emily R. Nodine

FIU Electronic Theses and Dissertations

Estuaries are dynamic on many spatial and temporal scales. Distinguishing effects of unpredictable events from cyclical patterns can be challenging but important to predict the influence of press and pulse drivers in the face of climate change. Diatom assemblages respond rapidly to changing environmental conditions and characterize change on multiple time scales. The goals of this research were to 1) characterize diatom assemblages in the Charlotte Harbor watershed, their relationships with water quality parameters, and how they change in response to climate; and 2) use assemblages in sediment cores to interpret past climate changes and tropical cyclone activity.

Diatom assemblages …

Harmful Algal Bloom (Hab) Communities And Co-Occurring Species In Relation To Near Shore Ocean Dynamics In San Luis Bay, California, Samuel Christopher Rankin

Master's Theses

The occurrence of phytoplankton taxa, with special focus on harmful algal bloom (HAB) taxa, was monitored for one year off the central coast of California to examine both their co-occurrence and physical and chemical variables influencing their temporal patterns. Bi-weekly samples were taken from October 6, 2008 to October 5, 2009 in San Luis Obispo Bay, CA. Canonical correspondence analysis (CCA) of weekly samples indicated that 46.1% of the variability in species abundance was explained by the variables in the model, higher than previous reports. Cluster analysis divided phytoplankton communities into HAB and non-HAB groups of species, while shared distribution …

Additions And Confirmations To The Algal Flora Of Itasca State Park Ii. Diatoms From Chambers Creek, Mark B. Edlund

Journal of the Minnesota Academy of Science

A survey of the summer diatom flora of Chambers Creek, Clearwater County, Minnesota, is presented, continuing an inventory of the algal flora from Itasca State Park. Chambers Creek is a short, second-order, hardwater stream with great habitat diversity and a rich algal flora. One hundred and twenty-six diatom taxa representing 45 genera are reported, with many new reports from the park. Recent taxonomic revisions have been incorporated into this study and seven new nomenclatural combinations proposed.

Phytoplankton Relationships To Water Quality In Lake Drummond And Two Drainage Ditches, Christine G. Phillips, Harold G. Marshall

Biological Sciences Faculty Publications

A twelve-month phytoplankton study was conducted in Lake Drummond and Washington and Jericho Ditches from December 1988 to November 1989. Four dominant phytoplankton groups were identified at these sites. These were the Bacillariophyceae, Cyanophyceae, Cryptophyceae and an autotrophic picoplankton component. Over the past 20 years there has been a decrease in the mean pH levels of Lake Drummond and the replacement of one its former major components, the Chlorophyceae, by the Cyanophyceae. Based on water quality analysis results and species diversity indices, Lake Drummond is classified as in an early eutrophic stage of development.

Diatom Phytoplankton And Periphyton Studies Of The Headwaters Of Henrys Fork Of The Snake River, Island Park, Idaho, Richard L. Clark

Theses and Dissertations

An ecological baseline study of the diatom flora was conducted on the headwaters of Henrys Fork of the Snake River, Idaho. The diatom flora of this spring fed drainage basin consisted of both phytoplankton and periphyton. Thirty-nine genera, two hundred forty-four species, eighty-two additional varieties, and seven additional forms were identified from these waters. Species of Melosira, Stephanodiscus, Fragilaria, Synedra, and Asterionella were found in the plankton of Henrys Lake and Island Park Reservoir. Diatoma, Fragilaria, Synedra, Eunotia, Achnanthes, Navicula, Pinnularia, Gomphonema, Cymbella, Nitzschia, and Surirella were the important genera present in the periphyton.