Life Sciences Commons^™

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 …

Lead Toxicology: A Study At The Intersections Of Community Health, Genetics, Reproduction, And Behavior, Sosina Abuhay 23, Lingli Zou '22, Sarah John '24, Dylan Koproski '23

Student Scholarship

Prior literature has indicated that toxic metal exposure can alter the circadian clock rhythm and lead to biological and physiological dysfunction. The purpose of this research was to study the impact of chronic exposure to lead on the circadian rhythm patterns of Drosophila Melanogaster. Fly locomotive activity was used as a measure of strength of the circadian rhythm after exposure to lead. It was hypothesized that higher concentrations of lead would have a greater impact on the circadian locomotor activity patterns of exposed Drosophila, specifically on the transition periods between “Morning” and “Evening.” Young adult male flies(1-3 days post-eclosion) were …

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 …