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Predation As A Vehicle To Aid Tunicate Invasion In The Biofouling Community, Helen Day

Master's Theses and Capstones

Competition for space can influence community dynamics in the sessile biofouling community. Within recent decades, community dynamics have shifted towards a community dominated by tunicates. This research proposed predation as a mechanism driving this shift.

In the Gulf of Maine, the non-native species Botrylloides violaceous became abundant when predators (i.e. the benthic fish Tautogolabrus adspersus and the sea star Asterias rubens) removed the cryptogenic (i.e. native) tunicate Molgula citrina. Moreover, B. violaceus was present in higher amounts in habitats with low abundances of M. citrina than it was in areas in which the two tunicate species were both abundant. Furthermore, …

Investigation Of Sex Change, Sex Differentiation And Stress Responses In Black Seabass (Centropristis Striata), Danielle C. Duquette

Master's Theses and Capstones

Black sea bass (Centropristis striata) have been the focus of research as an aquaculture species for several years due to their high consumer demand and limited seasonable availability. As protogynous hermaphrodites, black sea bass initially develop as females in the wild, and undergo sex reversal between 2 and 6 years of age. Previous studies demonstrated that in captivity, however, a significant number of fish differentiate initially as males, and sex reversal is hastened in females. Full control of reproduction is required for successful commercial culture. Since captive environments pose several sources of stress upon the cultured species, this research investigates …

Small Scale Raft Aquaponics: Evaluation Of Hybrid Striped Bass Growth And Plant Uptake Potential, Calvin Grant Diessner

Master's Theses and Capstones

Hybrid striped bass ([male]Morone saxatilis [female] Morone chrysopos) were successfully cultivated in two separate 48 day trials (t1 and t2) with seedlings of lettuce (Lactuca sativa cv. Rex) and pac choi (Brassica rapa cv. Win-Win) within a shared recirculating aquaponic system. It was determined that fish stocking density had no significant effect on the mean yield of lettuce and pac choi biomass in t1. Stocking density did have a significant effect on the elemental nutrients generated within the aquaponic systems. A nutrient deficiency was exhibited by the leaf tissue of pac choi grown with fish stocked at low a density …

Characterizing Winter Flounder (Pseudopleuronectes Americanus) Nursery Areas Using Otolith Microstructure And Microchemical Techniques, David Bailey

Master's Theses and Capstones

A preliminary study, using young-of-the-year winter flounder from 12 nursery areas from New Jersey to New Hampshire, evaluated indirect and direct measurements of nursery quality. Growth and condition indices (length d --1, weight d--1, Fulton's K and relative weight) were calculated from otolith microstructure to indirectly evaluate nursery quality. Boston Harbor, MA and Great Bay, NH were found to be the healthiest nurseries and the Niantic River, CT was found to be the least healthy nursery. In addition to these indirect indices, we conducted a study to determine the effectiveness of otolith microchemistry as a direct measurement of nursery habitat. …

A Statistical Analysis For Estimating Fish Number Density With The Use Of A Multibeam Echosounder, Madeline L. Schroth-Miller

Master's Theses and Capstones

Fish number density can be estimated from the normalized second moment of acoustic backscatter intensity [Denbigh et al., J. Acoust. Soc. Am. 90, 457-469 (1991)]. This method assumes that the distribution of fish scattering amplitudes is known and that the fish are randomly distributed following a Poisson volume distribution within regions of constant density. It is most useful at low fish densities, relative to the resolution of the acoustic device being used, since the estimators quickly become noisy as the number of fish per resolution cell increases. New models that include noise contributions are considered. The methods were applied to …

The Failed Introduction Of The Sea Anemone Sagartia Elegans In Salem Harbor, Massachusetts, Christopher David Wells

Master's Theses and Capstones

Many studies have reported the arrival and subsequent range expansion of foreign species within the marine ecosystems, but few studies have documented species that arrive and fail to establish. In 2000, the sea anemone Sagartia elegans (Dalyell, 1848) was first found in Salem, MA and persisted seasonally until the winter of 2010-2011 after which it has not been found. In both laboratory and field based temperature growth studies, S. elegans began regressing in size at 11 °C, stopped asexually reproducing at 9 °C, and died by 4 °C; these temperatures are far above the average winter sea surface temperature in …

Hemoglobin Type, Egg Buoyancy, And Antifreeze Glycoprotein Production As Mechanisms For Adaptive Variation In Gulf Of Maine Atlantic Cod (Gadus Morhua), Amanda R. Clapp

Master's Theses and Capstones

Three physiological traits were examined to compare captive populations of winter- and spring-spawning cod from the Gulf of Maine, as differences in these traits have been observed in other locally-adapted subpopulations. Daily mean neutral buoyancy of hatchery-spawned eggs was observed at three temperatures (5, 10, and 12°C) and three photoperiods (15:9, 9:15, and 24:0 L: D) at 12°C. Body fluids of larvae held at 0°C for five days were tested for antifreeze glycoproteins (AFGPs) to determine the onset of AFGP production. Juveniles held at 0°C were bled between 20 and 35 days to determine induction time for AFGP production. Hemoglobin …

Nonlinear Evaluation Of Stock Assessment And Marine Ecosystem Models, Laura Storch

Master's Theses and Capstones

In fisheries management, single-species stock assessment models use fisheries-dependent catch and landings data along with fishery-independent estimates of relative or absolute abundance to make estimates of species biomass for a given area. This output is used by the Atlantis marine ecosystem model as input. Atlantis uses an array of physical, biological, and anthropogenic factors to predict biomass for individual species or functional groups of species. Nonlinear analysis was used to assess the output for both the stock assessment, and Atlantis models for the marine ecosystem off the California coast. The number of time series displaying nonlinear characteristics decreases from raw …

Aspects Of The Reproduction Of An Invasive Crab, Hemigrapsus Sanguineus, In Northern And Southern New England, Emily F. Gamelin

Master's Theses and Capstones

Populations of the invasive shore crab, Hemigrapsus sanguineus , were studied in northern and southern New England to determine if crabs differ in reproductive behavior or characteristics between these regions. Additionally, effects of temperature on reproductive activity were quantified through laboratory experimentation.

Number of broods per season increased with temperature, but the seasonal total was limited to three broods in laboratory experiments. Broods experienced limited success at the lowest temperature, 10°C. The reproductive season was longer at lower latitudes, and females at this site had smaller average ovigerous size. Patterns of ovigery varied between the regions, suggesting the production of …

Evaluating Sampling-Induced Stress In Atlantic Cod (Gadus Morhua), Travis S. Ford

Master's Theses and Capstones

Atlantic cod, Gadus morhua, have historically been regarded as one of the most commercially and recreationally important fishes in the Gulf of Maine. All fish involved in fishing and aquaculture are subject to stress, indicated by elevated plasma cortisol concentrations. Given the amount of research conducted on Atlantic cod, stress, and cortisol, little has been done to compare different blood sampling methods and the effects they might have on plasma cortisol concentrations, particularly in adult fish. This study examined three different methods of repeated blood sampling (standard handling caudal vessel puncture, reduced handling caudal vessel puncture, and cannulation) in Atlantic …

The Influence Of Stocking Density And Acoustic Conditioning On The Behavior And Growth Of Atlantic Cod, Gadus Morhua, Daniel Ward

Master's Theses and Capstones

The goal of experiment one (Chapter One) was to determine if stocking density had an influence of the swimming behavior and spatial distribution of adult cod that were being raised in an aquaculture cage at the University of New Hampshire's Coastal Marine Laboratory. Acoustic telemetry and underwater video were used to quantify the behavior and distribution of cod that were stocked at four densities (5, 10, 25 and 45 kg/m³). At the lowest density (5 kg/m³) cod remained deep in the cage and spent 64.3 +/- 0.8% of their time below 1.80m (of a 2.70m cage). This contrasts to the …

Evaluation Of The Time Tension Line Cutter (Ttlc) As A Whale-Safe Fishing Gear Option, Timothy S. Pickett

Master's Theses and Capstones

The Time Tension Line Cutter (TTLC) is a device designed to limit the severity of entanglement of whales, the critically endangered North Atlantic Right Whale (NARW) in particular, in passive fishing gear. In this study, an evaluation of the performance of the TTLC was conducted using a series of lobster trawl tows, as well as a pilot study to test the durability and fishability of the TTLC in real fishing situations.

The trawl tow test data were collected for 5, 10, and 20 trap trawls, consisting of end line loading and trap elevation measurements. The time to cut (TTC) was …

Effects Of Sedimentation And Periphyton Communities On Embryonic Rainbow Smelt, Osmerus Mordax, Lauren Helena Wyatt

Master's Theses and Capstones

The decline of anadromous rainbow smelt (Osmerus mordax) populations has been suspected to be linked to anthropogenic causes. Increased runoff from agriculture and urbanization has led to additional sediment inputs and eutrophying compounds in rivers. The aim of this study was to assess the survival of embryonic rainbow smelt from fertilization through hatching under varying levels of sedimentation (0.00, 0.25, 1.00, and 6.00 g per 45.6 cm 2) and with periphyton communities of different biomass and algal composition. Additionally, embryo survival was assessed when cultured on periphyton in combination with sterilized sediment or eutrophying compounds (nitrates and phosphates). Oxygen consumption …

Fine-Scale Activity, Distribution And Habitat Utilization Of Atlantic Cod (Gadus Morhua) On The Ipswich Bay Spawning Ground, Laughlin Siceloff

Master's Theses and Capstones

Data storage tags (DSTs) and acoustic telemetry were applied to examine cod spawning habitat utilization in Ipswich Bay and compare seasonal activity patterns. I tagged 200 spawning cod in Ipswich Bay during April--May 2006 with DSTs recording depth and temperature. Twenty-six cod were also implanted with acoustic transmitters and relocated manually and with stationary listening stations during May and June. Twenty-five DSTs were returned, showing that most cod departed the spawning ground during May and June and dispersed throughout the western Gulf of Maine. Cod shared a low vertical activity pattern in Ipswich Bay, but adopted various site-specific vertical behaviors …

Expanding The Availability Of Sustainable Seafood: Uncovering Barriers For Retailers, Lindsey Piilani Fong

Master's Theses and Capstones

In the fall of 2008, a mail survey was distributed to New England retailers to assess their knowledge and interest regarding 'sustainable seafood' campaigns and eco-labeling programs, as well as identify incentives to help overcome perceived barriers that prevent the distribution of sustainably harvested and labeled seafood in grocery stores. This investigation yields valuable insight for increasing the effectiveness of efforts that aim to influence consumer purchasing of seafood, as there has been little prior investigation of seafood eco-label systems used at the point-of-purchase, or retailer willingness to offer sustainably produced seafood products. This study found that many retailers are …

Laver (Porphyra Spp) And Soy Protein Concentrate As Alternative Proteins In Diets For Juvenile Atlantic Cod, Gadus Morhua, Abigail B. Walker

Master's Theses and Capstones

Fishmeal is the main ingredient in formulated fish feeds, and the cost of this commodity is the largest and most volatile recurrent expenditure by the finfish aquaculture industry. Additionally, the reliance on wild-harvested forage species raises concerns about the industry's ecological impacts. Marine macroalgae and soy-derived feed ingredients both have merits as alternative proteins for piscivorous marine fish. Atlantic cod, in particular, have a highly adaptable digestive system and perform well with alternative protein diets.

Atlantic cod, Gadus morhua, juveniles (initial body weights: 15.6 g, 87.9 g, and 15.92 g) were fed iso-nitrogenous, iso-caloric diets to evaluate two alternative proteins. …

The Behavior Of Atlantic Cod, Gadus Morhua, In An Offshore Net Pen, Christopher B. Rillahan

Master's Theses and Capstones

Aquaculture is one of the fastest growing food producing sectors of the world, with an annual compounding growth rate of 8.8% (since 1970). In spite of the rapid growth, scientific and public concerns have arisen about the sustainability and environmental impacts of the industry, including aquaculture's dependence on wild fish products, eutrophication from animal waste and uneaten food, and escapement of genetically altered farming stock. The use of behavioral studies may help refine commercial aquaculture by obtaining information to design operations that optimize growth, and feed utilization, while increasing production and animal well being. The goal of this study was …

A New Perspective: Atlantic Herring (Clupea Harengus) As A Case Study For Time Series Analysis And Historical Data, Emily Klein

Master's Theses and Capstones

This thesis endeavors to develop methods for the historical analysis of a specific species and location to begin understanding fishery patterns and change over time. The main goal was to develop statistical methods to address historical data and provide long-term information on fishery trends and potential relationships between the fishery and outside influences. The Atlantic herring (Clupea harengus) fishery was investigated for underlying patterns and the possible impact of outside variables and events from 1870 to 2007.

In the Gulf of Maine, Atlantic herring (Clupea harengus) provide critical forage for many economically valuable species, while supporting a major New England …

Early Performance Of Constructed Oyster Reefs In Great Bay, New Hampshire, Mark K. Capone

Master's Theses and Capstones

Several oyster reefs were constructed in Great Bay, New Hampshire using remotely-set oysters. A single large reef treatment and a cluster of several small reefs treatment were utilized to test hypotheses relevant to oyster restoration design, and to monitor early restoration reef performance. There was no significant difference in oyster size, density, and recruitment between two experimental reef structures, with both reef types having high survival and fast growth rates for the 2-year study. Both experimental reef structures had significantly higher recruitment rates than natural reefs in 2006, a year of relatively high recruitment (p < 0.05), and elevated yet not significantly higher recruitment rates in 2005, a weak recruitment year (p = 0.078). In situ fluorometry data showed that a restored reef can significantly impact chlorophyll-a levels in overlying water within two years of reef construction. Individual oyster clearance rates ranged from 1.87 L/hr--2.41L/hr.

Distribution And Feeding Behavior Of Early Life Stages Of The Northern Shrimp, Pandalus Borealis, In Relation To The Spring Phytoplankton Bloom In The Western Gulf Of Maine, Erin B. Hobbs

Master's Theses and Capstones

The northern shrimp Pandalus borealis is a commercially important crustacean found in the deep waters of western Gulf of Maine. In order to develop better fisheries management practices, it is essential to understand variability in P. borealis recruitment. Analysis of samples collected along a coastal transect (during 2005 and 2006), indicate cross-shore distribution of early planktonic larval stages is consistent with observed benthic distribution of ovigerous females. Timing of larval occurrence in relation to the spring phytoplankton bloom suggests that a match/mismatch with abundance of phytoplankton and zooplankton prey may be a primary determinant of recruitment success. Among the potential …

Investigation Of The Sex Determination Mechanisms In Summer Flounder (Paralichthys Dentatus) And Black Sea Bass (Centropristis Striata), Heidi R. Colburn

Master's Theses and Capstones

In many cultured finfish species, sexually dimorphic growth is observed, therefore, understanding the mechanisms of differentiation in fishes is necessary for successful aquaculture. Summer flounder (Paralichthys dentatus ) and black sea bass (Centropristis striata) are good candidate species for aquaculture because they easily adapt to culture conditions and have high market value. The production of monosex populations is advantageous in species exhibiting sexually dimorphic growth rates. The purpose of this research was to gain an understanding of the mechanisms involved in sex differentiation of summer flounder and black sea bass. In summer flounder, monosex female culture is beneficial because females …

Spawning Stock Identification Of Atlantic Cod (Gadus Morhua) In Us Waters Using Pan I And Microsatellite Genetic Markers, Timothy S. Breton

Master's Theses and Capstones

Most Atlantic cod (Gadus morhua) stocks within U.S. waters are currently in decline as a result of overexploitation and fishing pressure from commercial fisheries. A better understanding of the genetic structure of cod populations is essential to identify stocks for successful fisheries management. In this study, the genetic structure of cod from major temporally and geographically distinct spawning grounds in U.S. waters was investigated. Adult and juvenile cod were sampled from aggregations within the Gulf of Maine, Georges Bank, and southern New England waters in cooperation with commercial fishermen and state fishery biologists. Caudal fin clips were collected and analyzed …

Modeling Physical Controls On Northern Shrimp (Pandalus Borealis) Dispersal, Retention And Settlement Success In The Gulf Of Maine, Michael J. Bates

Master's Theses and Capstones

Understanding the population dynamics of commercially harvested species is critical to fishery management. Coupled physical-biological models are powerful tools for exploring interactions among species and their environment. This study creates a coupled, individual-based model to explore interactions between northern shrimp in the Gulf of Maine and their physical environment to try to understand the variability in their population from year to year and to draw hypotheses regarding spawning grounds, larval dispersal and settlement success zones for further study.

Model runs are performed using standardized winds to understand the general effects of variability in physical forcing on the population. Runs are …

Impacts Of Changing Water Temperatures On The Life Histories Of Two Invasive Ascidians In The Gulf Of Maine: Botryllus Schlosseri And Botrylloides Violaceus, Erica Westerman

Master's Theses and Capstones

The impact of temperature on organism life cycles has received great attention due to heightened awareness of global warming. Relative growth and reproductive development were monitored in two dominant ascidians from the Gulf of Maine to compare effects of rising temperatures on established ( Botryllus schlosseri) versus recently arrived (Botrylloides violaceus) species. Settlement panels were deployed at three sites with different temperature regimes (Damariscotta, ME, Newcastle, NH, and Salem, MA) during two growing seasons June 2005 to December 2006, and a recruitment study conducted May to December 2006. Both species had elongated breeding seasons in Salem, MA relative to the …

Developing A Kalman Filter Approach To Home Range Estimation: Applied To The Atlantic Bluefin Tuna (Thunnus Thynnus), Daniel Badger

Master's Theses and Capstones

Accurate estimation of an animal's home range, or utilization distribution, is of great importance to understanding the animal's role in the ecosystem, and for effective population management. Current methods for home range estimation often do not incorporate uncertainty in the observations of monitored animals. Given days without observations, they also have the potential to omit migration corridors when describing important habitat. Here the Extended Kalman filter is modified to return daily predicted geolocations, creating a most probable estimation of the true path the observed animal followed. Markov Chain Monte Carlo methods were used to map the uncertainty in this path …

A Case Study In Natural Resource Policy: Yellowstone Cutthroat Trout (Oncorhynchus Clarki Bouvieri) In The Greater Yellowstone Ecosystem, Brad Johnson

Master's Theses and Capstones

The Greater Yellowstone Ecosystem is hailed as one of the most intact temperate ecosystems in the world. Within the ecosystem the Yellowstone cutthroat trout has been noted as both a keystone species and an indicator of ecosystem health. As anthropogenic induced stress and its effects on natural systems have become more readily apparent, a call has risen for a new holistic form of natural resource policy development and implementation. The Ecosystem Approach, based on the principles of sustainability, is a multidisciplinary, cross-sectoral policy paradigm, which serves that function for this study.

This research analyzed the extent to which natural resource …

The Effects Of Photoperiod And Water Temperature On The Reproductive Development Of Black Sea Bass, Centropristis Striata, Katie Strait

Master's Theses and Capstones

Black sea bass are a potential candidate for marine aquaculture due to their high market value, high demand, and limited seasonal supply. One of the most significant impediments to commercial production of black sea bass is the lack of a year-round supply of eggs and larvae. Further, control of reproductive development is poorly understood in this species. Black sea bass are protogynous hermaphrodites that change sex between 2-5 years of age. It is unclear why adult black sea bass undergo sex change in the wild. Therefore, the first part of study sought to determine if density is involved in sex …

Environmental Effects On Early Life Stages Of American Shad (Alosa Sapidissima) And Rainbow Smelt (Osmerus Mordax ), Kristen Fuda

Master's Theses and Capstones

Recruitment of American shad (Alosa sapidissima) and rainbow smelt (Osmerus mordax) has steadily declined over the last few decades, possibly due to the construction of physical impediments to migration and increases in anthropogenic pollution. In order to elucidate environmental parameters influencing early life stages of anadromous fish, both laboratory and field studies were conducted. The effects of abiotic factors, including dissolved oxygen (DO), pH, salinity, nitrate, and phosphate, on hatch and survival of larval and juvenile American shad and rainbow smelt were examined in laboratory studies. Field studies on shad emigration were conducted in the Exeter River, and studies on …