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Assessing Changes In Freshwater And Marine Food Web Connections Following Restoration On The Penobscot River, Maine, Using Stable Isotope Analysis, Matthew Brewer Ms

Student Scholarship

Oiadromous fish provide ecological subsidies to freshwater and marine food

webs, connecting both ecosystems. A main goal of the Penobscot River Restoration

Project was to increase connectivity between food webs by removing two mainstem

dams, improving fish passage, and reintroducing river herring through stocking.

Oiadromous fish now reach historic spawning habitat that was not accessible for

centuries. As a result, river herring runs in the Penobscot River increased from

2,336 fish in 2009 to over 3 million fish by 2018. To assess food web connectivity in

the Penobscot watershed, I analyzed stable isotopes from samples collected before

(2009-2010) and after …

The Roleo F Selectionin Maintaining Mhc Variationi N Mammals: Heterozygotaed Vantage,R Area Llelea Dvantagea Nd Mate Choice, Carol Titterton Ms

Student Scholarship

The major histocompatibility complex (MHC) is the most polymorphic gene

region in jawed vertebrates. Its gene products play a critical role in determining

individual and population fitness by presenting foreign antigens to immune system

cells, thereby initiating immune response to pathogen and parasite infections and

cancer. I surveyed the literature to investigate how selection maintains such

important adaptive diversity in mammalian populations and how MHC diversity

affects individual and population fitness. Balancing selection in the form of either

heterozygote advantage or rare allele advantage has long been proposed as the key

mechanism for maintaining the extreme diversity in MHC gene …

Analysis Of Invasive Aedes Japonicus Populations And Bloodmeals In Rural, Suburban, And Urban Land-Use Conditions, Matthew Oberholtzer Ms

Student Scholarship

Adult female mosquitoes were collected at six sites with differing land-use and

livestock characteristics to characterize populations and bloodmeal habits of the invasive

vector mosquito species, Aedes japonicus in Southern Maine. Mosquitoes were collected

and DNA was extracted for PCR amplification of cytochrome C oxidase I (COi)

mitochondrial DNA for barcoding analysis of vertebrate bloodmeals. A total of 7460

adult female mosquitoes were collected, with 444 being Ae. japonicus (5.6%). This

indicates an established breeding population of Ae. japonicus in Southern Maine. The

rural site adjacent to livestock had the highest yield of total mosquitoes as well as the

catch …

Alewife (Alosa Pseudoharengus) Contributions To Lake Phosphorus Budgets: Implications For Management, Meg "Rue" Farley Thurrell Ms

Student Scholarship

As human-made dams are removed and fish passage at dams is improved in

support of restoration efforts, anadromous alewives (Alosa pseudoharengus) gain

access to historic spawning grounds. As they migrate to spawn, adult alewives import

marine derived nutrients to lakes and impoundments. Young of year alewives (juveniles)

export nutrients as they emigrate to the sea. These nutrients support primary

production and are incorporated into freshwater food webs. However, many lakes in

New England are mesotrophic or eutrophic. Additional nutrients, specifically

phosphorus (P), may exacerbate water quality issues. To examine these issues, I

compared outputs ofan alewife nutrient and population model …

Using Stable Isotopes And Diet Analysis To Assess The Potential For Competition And Coexistence Among Coyotes (Canis Latransl, Red Foxes (Vulpes Vulpes), And Gray Foxes (Urocyon Cinereoargenteus) In Maine, Henry M. Masters

Student Scholarship

When two species compete for food, one species typically outcompetes the other. Subordinate species can alleviate costs of competition by reducing diet overlap, promoting coexistence. Non-native coyotes (Canis latrans) and historically native gray foxes (Urocyon cineroargenteus) have expanded their range in Maine and may compete with native red foxes (Vulpes vulpes). To investigate competition, I analyzed stable isotopes and stomach contents to determine if coyotes, red foxes, and gray foxes differed in use of anthropogenic foods and trophic position. I predicted that coyotes utilize anthropogenic foods the least (lowest δ13C), and red foxes utilize …

An Evaluation Of Elemental Composition Of Soils Associated With Ground Nesting Ants In The Family Formicidae In Somerset County, Maine, Haley H. Depner

All Student Scholarship

Ants are keystone organisms and engineers in many ecosystems, playing an important role in nutrient cycling and rearrangement of organic and inorganic materials through foraging, waste management and, in subterranean species, nest construction and maintenance. In this study, I conducted elemental analysis of soils for calcium, copper, iron, potassium, manganese and zinc in and around the colonies of subterranean nesting ants. The two-step analysis used in this study utilizes the efficiency of X-Ray Fluorescence (XRF) Spectrometry to look for overall trends in elemental composition followed by Flame Atomic Absorbance (AA) to achieve higher resolution of select elements of interest as …

Pore Water Salinity Drives Brackish Vegetation Change In Salt Marsh Tidal Restoration, Shri Andrea L. Verrill Ms

All Student Scholarship

Salt marsh vegetation plays an important role in building and maintaining elevation on the marsh surface. For marshes to persist as sea-level-rise (SLR) occurs, the marsh accretion process must increase elevation at a rate greater than or equal to the rate of SLR. If salt marshes do not maintain elevation above sea level, salt marshes will drown, and associated benefits to humans, fish, and wildlife, and their contribution to the health of estuarine and marine ecosystems will be lost. Salt tolerant plant species are adapted to frequent and prolonged periods of inundation with seawater and typically maintain elevation where they …

Anaerobic Co-Digestion Of Chlorella Vulgaris And Dairy Whey For Enhanced Methane Production, Paula Drouin Ms

All Student Scholarship

The anaerobic digestion process is an additional step that can be implemented at wastewater treatment facilities for the production of biogas (i.e. methane) that can be used to generate energy and significantly reduce the facility's energy cost. An emerging area of interest with anaerobic digestion is the inclusion of high-strength degradable organic waste (in addition to wastewater solids) that can lead to increased methane production by methanogens. Chlorella vulgaris (C. vulgaris), a species of green microalgae, is ubiquitous green alga often present at water-water treatment plants. I investigated its usefulness in an existing wastewater treatment process. Two investigations …

An Investigation Of Juvenile Alewife (Alosa Pseudoharengus) Habitat Use And Growth Using Natural Markers, Gregory Norman Labonte Ms

All Student Scholarship

This research attempts to connect patterns in growth and migration of an anadromous species. The goal of this research was to understand habitat movements and growth of juvenile alewives (Alosa pseudoharengus) in the Penobscot Estuary and Bay through the use of otolith microchemistry, otolith growth increments, and a laboratory stable isotope turnover study. Understanding the connection between growth and movement of juvenile alewives may lead to more accurate and sophisticated conservation and restoration methods for anadromous species.

Parental Experience And Its Effects On Reproductive Success In Common Loons, Brandon S. Braden Ms

All Student Scholarship

Common Loons (Gavia immer) are a highly territorial , long-lived species of waterbird that breed throughout the northern tier of North America. Loons form pair bonds seasonally, on their breeding territories, but overwinter separately. Much is known about environmental effects on loon reproductive success but little is known about how parental experience affects reproductive outcomes. I investigated the effects that individual experience and breeding pair length have on the reproductive success of Common Loons. The data I used were a compilation of individual territory occupancy and breeding records that were obtained by the Biodiversity Research Institute in Gorham, Maine from …

Approaches To Restoration: Assessing The Roles Of Structure And Function In Saltmarsh Restoration In Light Of Climate Change, Abby O. Pearson Ms

All Student Scholarship

The aim of this thesis is to review the current goals and methods for salt marsh restoration, to question how those goals and methods may change in light of global change, and to present a case study that offers a look at the kinds of information that can be gleaned by studying both structure and functionality in restoration.

Retrospective Examination Of Habitat Use By Blueback Herring (Alosa Aestivalis) Using Otolith Microchemical Methods, Molly Payne Wynne Ms

All Student Scholarship

Life histories of anadromous fish are difficult to examine due to constraints on direct observation. However, an understanding of patterns of habitat use is critical to management efforts since recruitment to spawning age is vital to population sustainability. Blueback herring (Alosa aestivalis) are anadromous fish that utilize a variety of freshwater, estuary and nearshore marine habitats. Rapid declines in their abundance and a subsequent petition for listing under the US Endangered Species Act in 2012 have ushered in an immediate need for life history information. This study focused on five river systems and seven spawning runs along the coast of …

The Varied Roles Of Induced Plant Responses In Species Interactions, Justine B. Roths Ms

All Student Scholarship

In this review, I will discuss indirect species interactions that occur as a result of herbivore-induced trait changes in plants. Species interactions are at the very core of the field of ecology. In particular, plant–insect herbivore interactions are of central importance as these two groups together consist of over 75% of the macroscopic diversity on earth. Historically, research has focused on pair-wise direct interactions however, more recently, the importance of indirect interactions has been widely acknowledged. Indeed, indirect interactions may be as strong and as common as direct interactions. Indirect interactions have been actively investigated in plant–insect systems, which are …

Flying Speed In Drosophila Melanogaster Selected For Fast Flight, Jess Wheeler Ms

All Student Scholarship

The aim of this study was to quantify the increase in flying speed in two replicate lines of Drosophila melanogaster (AA1 and AA2), after approximately 520 generations of selection for fast flight in a wind tunnel.