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Specific Dynamic Action, Growth And Development In Larval Atlantic Cod, Gadus Morhua, Jessica A. Geubtner Dec 2003

Specific Dynamic Action, Growth And Development In Larval Atlantic Cod, Gadus Morhua, Jessica A. Geubtner

Electronic Theses and Dissertations

The larval stage of marine fish is a period of rapid growth and development. Atlantic cod (Gadus morhua) are approximately 4-5 rnm in length upon hatch and feed endogenously from their yolk sac for the first week. After this time, larval cod must successfully capture live prey to survive and to fuel high growth rates of greater than 10%d". Previous studies have found that during exogenous feeding and at growth rates greater than 8%d1 larvae experience what appears to be cost free growth, where mass specific metabolic rate does not decrease with increasing mass. Due to size and condition constraints …


The Role Of Larval Thermal Tolerance In The Distribution Of Blue Mussel Species Within The Gulf Of Maine, Susan J. Limbeck Dec 2003

The Role Of Larval Thermal Tolerance In The Distribution Of Blue Mussel Species Within The Gulf Of Maine, Susan J. Limbeck

Electronic Theses and Dissertations

Two species of blue mussel, Myrilus edulis and Myrilus trossulus, are sympatric throughout much of the Canadian Maritime Provinces and into the Gulf of Maine. While the distribution of M edulis extends south to the Mid-Atlantic, that of M. trossulus ends abruptly in the Gulf of Maine. I have hypothesized that these differences in adult distribution are the result of species-specific variation in larval thermal tolerances. Previously, it has been shown that when reared at 20 OC, from 36 hour post-fertilization through settlement, M. trossulus had significantly higher mortality rates than M. edulis. This study examined whether species-specific differences in …


Analysis Of The Spatial Dynamics Of The American Lobster (Homarus Americanus) Fishery Along The Coast Of Maine, Kevin M. Scheirer Dec 2003

Analysis Of The Spatial Dynamics Of The American Lobster (Homarus Americanus) Fishery Along The Coast Of Maine, Kevin M. Scheirer

Electronic Theses and Dissertations

The American lobster (Homarus americanus) supports the most valuable commercial fishery in the northeastern United States, thus the fishery is critical to Maine's economy. No systematic study has been done to collect information about, identify, and quantify the spatial dynamics of the Maine lobster fishery. This project helps to provide a better understanding of Maine's lobster fishery dynamics, and it will aid f'iture efforts to improve the stock assessment of Maine's lobster fishery. The analysis consists of three distinct parts: (1) comparison of data collected by two separate fishery dependent sampling programs; (2) spatial analysis of electronic logbook data; and …


An Investigation Of The Cumulative Impacts Of Shrimp Trawling On Mud Bottom Fishing Grounds In The Gulf Of Maine: Effects On Habitat And Macrofaunal Community Structure, Anne W. Simpson Dec 2003

An Investigation Of The Cumulative Impacts Of Shrimp Trawling On Mud Bottom Fishing Grounds In The Gulf Of Maine: Effects On Habitat And Macrofaunal Community Structure, Anne W. Simpson

Electronic Theses and Dissertations

Despite the widespread occurrence of trawl fisheries on mud-bottoms, there is limited knowledge concerning the effects of trawling induced disturbance on these habitats and their resident macrofaunal communities. I investigated the cumulative impacts of seasonal commercial shrimp trawling on infaunal habitat and macrofaunal community structure on two mud-bottom fishing grounds in the Gulf of Maine from June 2000 - December 2001. One fishing ground located near the Outer Pumpkin Ledges (Pumpkin) experienced trawling activity during the 2000-2001 fishing season. In contrast, the other fishing ground near Monhegan Island was not trawled during the same period because shrimp abundances were low. …


Resilience Of Green Sea Urchin (Strongylocentrotus Droebachiensis) Populations Following Fishing Mortality: Marine Protected Areas, Alternate Stable States, And Larval Ecology, John Vavrinec Iii Aug 2003

Resilience Of Green Sea Urchin (Strongylocentrotus Droebachiensis) Populations Following Fishing Mortality: Marine Protected Areas, Alternate Stable States, And Larval Ecology, John Vavrinec Iii

Electronic Theses and Dissertations

The green sea urchin Strongylocentrotus droebachiensis has been aggressively fished in Maine since 1986 resulting in severe population declines throughout portions of the state. This research used Marine Protected Areas (MPAs) to evaluate the potential for recovery in depleted sea urchin populations. It was necessary to not only look at the direct impacts of the MPAs, but also at larval transport / supply and community interactions to gain a better understanding of the system. We found that MPAs in the Gulf of ~a!ne were of varied utility to restoring depleted sea urchin populations depending on location and community structure. MPAs …


Hydroperiod Of Wetlands And Reproduction In Wood Frogs (Rana Sylvatica) And Spotted Salamanders (Ambystoma Maculatum), Mary Beth Kolozsvary Aug 2003

Hydroperiod Of Wetlands And Reproduction In Wood Frogs (Rana Sylvatica) And Spotted Salamanders (Ambystoma Maculatum), Mary Beth Kolozsvary

Electronic Theses and Dissertations

Many amphibians rely on wetlands for reproduction and the differential distribution of amphibian species along a gradient of wetland permanence is striking, yet not absolute. Wood frogs (Rana sylvatica) and spotted salamanders (Ambystoma maculatum) are thought to rely on seasonal wetlands for greatest breeding success, but there is little documentation of their reliance on these or other habitats. In my first chapter, I studied these species in wetlands across a hydrologic gradient from seasonal wetlands of short flood duration to permanently flooded sites. My results indicate that wood frogs have greatest reproductive effort and success in …


Population Dynamics And Spatial Analysis Of The Maine Green Sea Urchin (Strongylocentrotus Droebachiensis) Fishery, Robert C. Grabowski May 2003

Population Dynamics And Spatial Analysis Of The Maine Green Sea Urchin (Strongylocentrotus Droebachiensis) Fishery, Robert C. Grabowski

Electronic Theses and Dissertations

Fisheries research on the green sea urchin in Maine has been limited despite its importance to the state's fishing industry. The objective of this thesis was to generate critical information for the management and monitoring of the Maine green sea urchin fishery. In particular there are three main areas of interest: (1) an investigation of biological reference points; (2) spatial analysis and biomass estimation, and (3) the development of a simulation framework approach to determine an optimal sampling strategy for the fishery-independent survey program. Biological reference points are markers conlrnonly used to monitor and manage fisheries. For the Maine sea …


Modeling Bird Species Occurrence In Current And Future Landscapes, Stephen Nicholas Matthews May 2003

Modeling Bird Species Occurrence In Current And Future Landscapes, Stephen Nicholas Matthews

Electronic Theses and Dissertations

With mounting evidence that global temperatures have increased significantly over the last century and the projections of greater changes in climate by the end of this century, understanding the potential consequences of these changes for species is essential to conservation efforts. Here I evaluate the potential response of birds to projected climate change by using regression tree analysis to create models of species distributions under current conditions from Breeding Bird Survey data and then project these models onto General Circulation Model (GCM) scenarios of global climate change. Before modeling species responses to climate change, I selected seventeen bird species to …


The Use Of Acoustics To Resolve Nightly Excursions Of Hyperbenthos, Heather U. Abello May 2003

The Use Of Acoustics To Resolve Nightly Excursions Of Hyperbenthos, Heather U. Abello

Electronic Theses and Dissertations

Acoustic analysis of die1 vertical migration in the Darnariscotta River estuary, Maine, showed a fairly regular nightly increase in biovolume (mm3 m'3) of organisms in the water column, presumed to be due to emergence, the entry of hyperbenthic organisms into the water column. Timing of these events was significantly correlated with time of sunset and time of sunrise for more than 50% of the dates where emergence and re-entry could be identified, between June and October 2002. Emergence traps indicate that the mysid shrimp, Neomysis americana, is the predominant migrator. Daily fluctuations in irradiance influence the timing of emergence fiom …


Effects Of Small-Gap Timber Harvests On Songbird Community Composition And Site-Fidelity, Mitschka John Hartley May 2003

Effects Of Small-Gap Timber Harvests On Songbird Community Composition And Site-Fidelity, Mitschka John Hartley

Electronic Theses and Dissertations

I investigated effects of small-gap timber harvests on bird communities at nine sites (10 ha each) within the Penobscot Experimental Forest (PEF), grouped into three replicated "blocks" (three sites each). Blocks were randomly treated with three treatments: 10% harvest, 20% harvest, and no harvest (i.e., control). I examined how treatments affected breeding songbird abundance, richness, and site-fidelity over four consecutive summers, including 1-3 years before and after each site was harvested. Ability to detect treatment effects was limited by the small number of replicates, but power analyses indicated that given the experimental design and observed variability, there was a high …


Scope For Activity, Specific Dynamic Action And Growth In Early Juvenile Stages Of Atlantic Cod, Gadus Morhua, Sorren Lund Hansen May 2003

Scope For Activity, Specific Dynamic Action And Growth In Early Juvenile Stages Of Atlantic Cod, Gadus Morhua, Sorren Lund Hansen

Electronic Theses and Dissertations

Growth rates of early life stages of Atlantic cod (Gadus morhua) are very high, but decline, as the fish grow larger. Little is know about the physiological processes that facilitate and regulate this growth pattern. In this study, feeding and swimming metabolism were measured in individual juvenile Atlantic cod (Gadus morhua) in order to investigate how energy are allocated to swimming and growth in fast growing stages of fishes. Metabolic rates were measured by the means of oxygen consumption using two "Brett-type" respirometers. The metabolic measurements were repeated several times in individual juvenile Atlantic cod with a wet body mass …


Lipid Solubilization By Marine Benthic Invertebrates, Ian M. Voparil May 2003

Lipid Solubilization By Marine Benthic Invertebrates, Ian M. Voparil

Electronic Theses and Dissertations

This work characterized the size of lipoidal colloids in benthic invertebrates' guts, using contact angle dilutions and imaging the fluorescence of the hydrophobic probe Nile Red. Deposit feeders and Nereis virens ingesting sediment were found to have micelles rather than emulsions in the gut. Gut fluids from Arenicola manna (a deposit-feeding polychaete) readily formed emulsions when incubated with mussel meat (Mytilus edulis; 80 g-mussel L"-gut fluid), suggesting that micelles form due to a paucity of emulsifying lipids in the gut. Lipid tracer contained in emulsion droplets was twice as likely to be captured by sediment than was tracer in micelles. …


Vaccines For Infection Salmon Anemia Virus, Nathan Edward Charles Brown May 2003

Vaccines For Infection Salmon Anemia Virus, Nathan Edward Charles Brown

Electronic Theses and Dissertations

Infectious salmon anemia (ISA) virus is an emerging pathogen of fanned Atlantic salmon. Due to the massive economic losses inflicted by the ISA virus, effective measures to control future outbreaks are necessary. An attractive method for preventing ISA virus from infecting stocks of Atlantic salmon is vaccination. DNA vaccination is a proven cheap, effective means of protecting fish from aquatic viruses. In this thesis DNA vaccination of Atlantic salmon was investigated. Three different strains of ISA virus were cultured and purified by density gradient ultracentrifugation. ISA virus RNA was isolated and used to amplify full-length cDNAs of five ISA virus …


Cloning Of Bovine Placental Lactogen And Production In Vitro, Stephanie A. Doucette Jan 2003

Cloning Of Bovine Placental Lactogen And Production In Vitro, Stephanie A. Doucette

Electronic Theses and Dissertations

Bovine placental lactogen (bPL) is a hormone produced by the fetal portion of the placenta during gestation. Although there is little known about the structure and function of the protein, it is thought to play a role in the growth of the fetus and in mammary growth and differentiation. Attempts have been made to heighten the understanding of bPL through the use of recombinant DNA technology. Thus far, researchers have been able to produce the recombinant molecule in bacteria cells. Bacteria, however, are incapable of carrying out some of the post-translational modifications characteristic of mammalian proteins. For example, unlike native …


Effect On Heartbeat Of Drosophila Melanogaster Of Mutations In The Calcium Channel Encoding Cacophony Gene And Its Interaction With The Rna Helicase Mutant Maleless^Napts, Vanessa Mcgowan Jan 2003

Effect On Heartbeat Of Drosophila Melanogaster Of Mutations In The Calcium Channel Encoding Cacophony Gene And Its Interaction With The Rna Helicase Mutant Maleless^Napts, Vanessa Mcgowan

Electronic Theses and Dissertations

There is a lack of information concerning the genetics of heart disease, especially of those due to aberrant pacemaker activity. Drosophila melanogaster is an ideal candidate for research in this area because of its suitability to genetic manipulation and its accessible genetic database. What is most compelling, however, is that the genesis of heartbeat is Drosophila is strikingly similar to that in many other organisms, including mammals. The myogenic heart of DrosophiIa melanogaster is stimulated to contract by a caudal pacemaker, which is regulated by ion channel interactions. A voltage-gated calcium channel of PIQ- or N-type is implicated in the …