Life Sciences Commons^™

Effects Of Light And Macroinvertebrate Consumers On Detrital Microbial Biofilms In Streams, Cheyenne M. Brady

Master's Theses

In lotic freshwater systems, aquatic macroinvertebrates are key processors of biofilms that grow upon organic matter. Although macroinvertebrate effects on biofilms may depend on light availability, the combined effects of consumers and light remain unexplored. Here, I conducted experiments to test effects of presence/absence of the omnivorous shrimp Macrobrachium ohione and the shredding caddisfly Pycnopsyche sp. on Liriodendron tulipifera litter biofilms in experimental streams under light or darkness. I measured litter-associated algal, fungal and bacterial biomasses and production rates, as well as litter decomposition, over 49 days. Both experiments exhibited significant positive effects of light on algal productivity and interactions …

Urban Stream Restoration: An Evaluation Of Material Processing And Conveyance Channels, Madeline Berg

Masters Theses, 2010-2019

Stream restoration is gaining popularity in the Mid - Atlantic region to offset impacts from urbanization. Increased levels of impervious surfaces, decreased vegetation along banks, and changes in water flow patterns make urban stream ecosystems flashy and result in high erosion rates, increasing the amount of nutrients entering the Chesapeake Bay. Different restoration practices can play a large role in the amount of nutrients and organic matter leaving a stream and the amount of habitat that is present in-stream.

Due to the recent interest in stream restoration as a tool to help the health of the Chesapeake Bay, this study …

Functional Feeding Groups Of Aquatic Macroinvertebrates On Natural And Artificial Leaves In Forested Stream Habitats In The Sebago Lake Land Reserve, Sam H. Matey, Kala Freytag Wistar

Thinking Matters Symposium Archive

We investigated preferential insect colonization of natural versus artificial leaves in forested streams to determine the impact of invertebrate-substrate associations on macroinvertebrate community composition and ecosystem nutrient cycling. We created 10 onion bags filled with natural maple leaves and 10 filled with artificial maple leaves, and placed 5 of each in two forested streams, one larger and one smaller, in the Sebago Lake Land Reserve in Standish, Maine. We identified the aquatic macroinvertebrates found on these samples after approximately one month to order-level and used Maine DEP biomonitoring data and functional feeding group taxonomies to classify macroinvertebrates by functional feeding …

Inferring Food Web Structure To Identify Seasonal And Longitudinal Patterns In Ogeechee River Invertebrate Communities, Julien Marc Buchbinder

Electronic Theses and Dissertations

Understanding how the structure and function of aquatic communities vary across space and time is essential for proper management of freshwater ecosystems. Current management relies on rapid biomonitoring using metrics of community structure, but metrics that incorporate ecosystem processes and functions are only just beginning to see use in assessment and management. Food webs inferred from known species interactions have been proposed as a method of incorporating function into bioassessment without expending extra effort or sacrificing the cost-effectiveness of current monitoring schemes. To apply food webs in biomonitoring, it is first necessary to understand how communities and food webs vary …

Effects Of Climate Variability: A Long-Term Perspective On Leaf Litter Processing In The Ogeechee River, Jose A. Sanchez

Electronic Theses and Dissertations

The Intergovernmental Panel for Climate Change (IPCC) predicts a rise in temperatures and changes to precipitation patterns for the 21^st century. These changes are expected to lead to a higher frequency of extreme events such as drought and floods which lead to the alteration of the hydrology, communities, and processes of freshwater ecosystems. Leaf litter decomposition in stream ecosystems is an important component of the energy and nutrient cycle representing a food source for aquatic organisms. This has made it a tool for assessing long term responses to disturbance due to changes in the assemblage of macroinvertebrates that …

Environmental Factors Associated With Benthic Macroinvertebrate Communities In Arctic Lakes, Northwest Territories, Rachel Cohen

Theses and Dissertations (Comprehensive)

Lake water quality and the macroinvertebrate communities in Arctic regions are threatened by increased development and climate change. In order to understand how macroinvertebrate communities may respond to their changing environment, I performed a biological and water quality survey of 46 Arctic lakes located in the Gwich’in Settlement Area and the Inuvialuit Settlement Region of the Northwest Territories. Using these survey data, I performed two interrelated studies that asked: 1) how artificial pit lakes associated with gravel extraction for road development compared with natural lakes in terms of their water quality, morphometry, and macroinvertebrate communities; and 2) how water quality …