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Full-Text Articles in Marine Biology

Dolphin Behavioral Responses To Uncrewed Aerial Systems As A Function Of Exposure, Height, And Type, Savannah Damiano May 2023

Dolphin Behavioral Responses To Uncrewed Aerial Systems As A Function Of Exposure, Height, And Type, Savannah Damiano

Electronic Theses and Dissertations

Uncrewed aerial systems (UAS) are becoming a standard tool in the study of cetaceans, however, a comparative assessment of animal responses to UAS has not been established to gauge the most effective systems for cetacean study. We utilized Dolphin Quest Bermuda’s eleven bottlenose dolphins as subjects for such an investigation taking place over five weeks in 2022 and five weeks in 2023. The dolphins were evaluated for investigative behavioral responses to six off-the-shelf UAS types and a custom fixed wing system. Each UAS was flown in decreasing height vertically above the main dolphin lagoon to evaluate dolphin behavioral responses in …


Optimizing Strategies To Hydraulically Plant Atlantic Salmon Eggs Based On Fry Dispersal Patterns, Ernest J. Atkinson May 2023

Optimizing Strategies To Hydraulically Plant Atlantic Salmon Eggs Based On Fry Dispersal Patterns, Ernest J. Atkinson

Electronic Theses and Dissertations

The Gulf of Maine Distinct Population Segment of Atlantic Salmon has suffered from habitat loss and exploitation over the last century. Hatchery supplementation has prevented the extirpation of the species, but stocking methods represent tradeoffs between survival, domestication, and logistics. Egg planting, the use of eyed embryos, maximizes natural rearing opportunities which can be important for adaptation. This method, however, is logistically demanding and requires significant labor over large spatial, but short temporal, scales dictated by the ontogeny of the fish. However, the survival and dispersal behavior of Atlantic Salmon fry immediately after emergence from eggs planted in artificial nests …


Investigating Salinity Intrusion Effects On Sapelo Island, Georgia Using Benthic Macroinvertebrate Bioindicators, Raymond Paul Kidder Ii Jan 2023

Investigating Salinity Intrusion Effects On Sapelo Island, Georgia Using Benthic Macroinvertebrate Bioindicators, Raymond Paul Kidder Ii

Electronic Theses and Dissertations

Coastal wetlands are threatened by the compounding effects of sea level rise and historical land modification. Historically, much of Sapelo Island, Georgia was deforested and drained using a series of ditches and canals to create arable land fit for agriculture and to provide drainage to the inhabited parts of the island. Today, this network of artificial channels is believed to be facilitating the movement of saltwater from the nearby estuary into freshwater areas on the interior of the island. This study aimed to better understand the frequency and magnitude of salinity intrusion events along with their resulting impacts to the …


Understanding The Impacts Of Anthropogenic Effects An Habitat Variability Interactions On Maine's Rocky Intertidal Ecosystem, Laura Braun Dec 2022

Understanding The Impacts Of Anthropogenic Effects An Habitat Variability Interactions On Maine's Rocky Intertidal Ecosystem, Laura Braun

Electronic Theses and Dissertations

The rocky intertidal ecosystem is an important ecological and cultural aspect of the picturesque Maine coast, playing a vital role in not only Maine’s coastal ecosystem, but also to Maine’s economy. It’s distinct community structure along the sharp elevational gradient and the presence of daily stressors (wave action, heat, and desiccation), make the rocky intertidal ecosystem an important model ecosystem to monitor for effects from anthropogenic impacts. In this thesis, I describe attempts to monitor and understand the impacts of two of these anthropogenic impacts on this system: climate change and industrial harvesting of Ascophyllum nodosum along Maine’s coast. For …


Microplastic Accumulation In The Digestive Tract Of Young-Of-Year Atlantic Sharpnose Sharks (Rhizoprionodon Terraenovae) In The Grand Strand, Sc, Andrew Curtis Sitlinger Dec 2022

Microplastic Accumulation In The Digestive Tract Of Young-Of-Year Atlantic Sharpnose Sharks (Rhizoprionodon Terraenovae) In The Grand Strand, Sc, Andrew Curtis Sitlinger

Electronic Theses and Dissertations

This study focused on the presence and accumulation of microplastic fibers in the digestive tract and livers of young-of-year Atlantic Sharpnose Sharks (Rhizopriondon terraenovae) from two sampling locations along the Grand Strand of South Carolina. R. terraenovae is a small, mesopredatory elasmobranch found abundantly along northwestern Atlantic Ocean coastlines. Thirty specimens of R. terraenovae were collected from May through August of 2020. Microplastics were found in all specimens. A total of 672 plastic particles were identified over the course of the study, with an average of 22.4 ± 10.5 (SD) plastics per specimen. The majority of the plastics were classified …


The Impacts Of Embryonic Arsenic Exposure Of Fundulus Heteroclitus, Torey Bowser Aug 2021

The Impacts Of Embryonic Arsenic Exposure Of Fundulus Heteroclitus, Torey Bowser

Electronic Theses and Dissertations

Arsenic is a toxic metalloid that exceeds safe drinking water standards in groundwater in many locations worldwide. Arsenic exposure in fish has been linked to destruction of gill tissues, impairment of growth, decreased muscle mass, memory impairment, increased aggression, and avoidance behaviors. We examined the behavior of mummichogs (Fundulus heteroclitus) following arsenic exposure during development in two studies. Embryos were collected from fish from three reference sites: Scorton Creek (SC), Massachusetts, Wells Harbor (WE), Maine, and Block Island (BLOC), Rhode Island and two contaminated sites: Callahan Mine (CM), Brooksville, Maine, and New Bedford Harbor (NBH), Massachusetts. Embryos were …


The Impacts Of Climate Change On The Gulf Of Maine Northern Shrimp (Pandalus Borealis) Distribution, Reproduction, And Life, Hsiao-Yun Chang Aug 2021

The Impacts Of Climate Change On The Gulf Of Maine Northern Shrimp (Pandalus Borealis) Distribution, Reproduction, And Life, Hsiao-Yun Chang

Electronic Theses and Dissertations

The Gulf of Maine northern shrimp (Pandalus borealis) once supported a significant winter fishery for the Gulf of Maine (GOM). Although the shrimp fishery is not comparable to the lobster business, it provided fishermen and many coastal communities jobs and incomes in winters after lobster seasons. However, a moratorium has been put on the shrimp fishery since 2014 due to record low population abundance and perceived recruitment failures. The recruitment failures have been correlated with warming water temperatures over the past decade. The GOM has been recognized as experiencing rapid warming as a result of global climate change. …


The Role Of Symbiotic Algae In The Acclimatization Of Oculina Arbuscula To Ocean Acidification, Erin M. Arneson Jan 2021

The Role Of Symbiotic Algae In The Acclimatization Of Oculina Arbuscula To Ocean Acidification, Erin M. Arneson

Electronic Theses and Dissertations

Ocean acidification (OA) caused by CO2 emissions is projected to decrease seawater pH to 7.6 by 2100. Scleractinian corals are at risk because excess H+ in seawater binds to carbonate (CO32-), reducing its availability for CaCO3 skeletons. The energy demand for skeletal growth increases as pH decreases because corals must actively purge excess H+ from their seawater sourced calcifying fluid to maintain high calcification rates. In scleractinian corals it is hypothesized that photosynthesis by symbiotic algae is critical to meet this increased energy demand. To test this hypothesis, I conducted laboratory and field …


Assessing Habitat Suitability Of Ribbed Mussels (Geukensia Demissa) In Georgia Salt Marshes By Examining Predicted Mussel Densities And Mussel Population Parameters, William K. Annis Jr Jan 2021

Assessing Habitat Suitability Of Ribbed Mussels (Geukensia Demissa) In Georgia Salt Marshes By Examining Predicted Mussel Densities And Mussel Population Parameters, William K. Annis Jr

Electronic Theses and Dissertations

Geukensia demissa (ribbed mussel) is an ecology important bivalve that has the potential to contribute to salt marsh restoration. Understanding the factors that contribute to the distribution of mussels can help inform managers on choosing locations to optimize the survivorship of mussels in restoration projects. This study sought to model mussel densities across the coast of Georgia and to compare predicted mussel densities with mussel population parameters as means to gauge habitat suitability. Mussel densities were collected through field surveys across a range of salt marshes along the coast of Georgia and were compared with spatial data such as distance …


Assessing Predator Risk To Diadromous Fish Conservation In The Penobscot River Estuary, Lauri Leach Dec 2020

Assessing Predator Risk To Diadromous Fish Conservation In The Penobscot River Estuary, Lauri Leach

Electronic Theses and Dissertations

Successful conservation of pinnipeds in the northwest Atlantic has led to increasing populations of harbor (Phoca vitulina) and gray seals (Halichoerus grypus) in the Gulf of Maine. Seals are often perceived as predators and competitors for fish, and as a result, come into conflict with fisheries and fish conservation. Increasing numbers of seals have become a recent concern in the Penobscot River Estuary in Maine, as habitat restoration and diadromous fish conservation have been top priorities in this region for the past decade.

To understand how pinnipeds are responding to these efforts, as well as the risks they pose to …


From Phocine Distemper To Avian Influenza: A Study Of Immunogenetic Diversity In Two Sympatric Pinniped Species, Alayna K. Gigliotti Aug 2020

From Phocine Distemper To Avian Influenza: A Study Of Immunogenetic Diversity In Two Sympatric Pinniped Species, Alayna K. Gigliotti

Electronic Theses and Dissertations

Gray (Halichoerus grypus) and harbor (Phoca vitulina) seals are sympatric species that inhabit the North Atlantic and have been subject to mortality events from disease outbreaks, particularly phocine distemper and avian influenza virus. Across mortality events, gray seals tend to exhibit a higher survival rate, which could be explained by various ecological factors impacting rates or direction of selection in parts of the genome related to the immune system. These factors could include haul-out site density, habitat, and degree of inter/intraspecies interaction. This research aims to compare genetic diversity within the Major Histocompatibility Complex (MHC) class …


Distributions And Abundances Of The Red Tide Dinoflagellate Alexandrium Catenella In The Eastern Gulf Of Maine And Bay Of Fundy In Relation To Diatoms In June, July And August Of 2019, Kimberly Lina D'Adamo Aug 2020

Distributions And Abundances Of The Red Tide Dinoflagellate Alexandrium Catenella In The Eastern Gulf Of Maine And Bay Of Fundy In Relation To Diatoms In June, July And August Of 2019, Kimberly Lina D'Adamo

Electronic Theses and Dissertations

A series of three oceanographic survey cruises were conducted in June, July, and August of 2019 in the northeastern Gulf of Maine and Bay of Fundy. Surface water samples were collected and analyzed for enumerations of cell densities of the dinoflagellate Alexandrium catenella in relation to cell densities of diatoms. Hydrographic profiles of temperature, salinity, and nutrients (silicate and nitrate) were also made at each station. Data were analyzed to determine if there was any statistically significant evidence of allelopathic interference imparted by diatoms that impede A. catenella. A. catenella cells were most abundant in June, reaching 6,195 cells per …


Surface Levels, Keisha Brathwaite Aug 2020

Surface Levels, Keisha Brathwaite

Electronic Theses and Dissertations

Surface Levels are depictions of unobserved and imperceptible realities of many phytoplankton exteriors. The exhibition explores various structures, textures, and repetitious forms from microscopic surfaces of objects that cannot be seen with unaided eyes. Electron microscopy is used to perceive and analyze these otherwise unseeable surfaces in depth. Magnifications provide a reference in creating three- and two-dimensional works that are minimalistic and abstract at a visible level. This abstract 3D/2D image collection is translated into material expressions using acrylic sheets, acrylic ink, and wood as the main media for construction of individual works. Collectively, they serve to make the invisible …


Sourcing And Evaluating The Use Of Detritus As A Supplementary Diet For Bivalve Aquaculture Using Stable Isotopes And Fatty Acid Biomarkers, Adrianus C. Both May 2020

Sourcing And Evaluating The Use Of Detritus As A Supplementary Diet For Bivalve Aquaculture Using Stable Isotopes And Fatty Acid Biomarkers, Adrianus C. Both

Electronic Theses and Dissertations

Detritus is a ubiquitous component of ecosystems and an important fuel for secondary production. Due to the extractive nature of bivalve aquaculture, detritus is often incorporated into carrying capacity and growth models for cultured bivalves. However, despite the complexity and difficulty in obtaining direct measurements, detritus is often treated as a homogeneous food source in models. Further understanding the role detritus plays in the diet of cultured bivalves could lead to more comprehensive and accurate models as well as more informed site selection for growers. The purpose of this study was to assess the abundance, bioavailability, and contribution of detritus …


The Effects Of Boring Sponge Infestation On Condition, Growth, And Sex Change In Crepidula Fornicata, Nicole L. Kleinas Jan 2020

The Effects Of Boring Sponge Infestation On Condition, Growth, And Sex Change In Crepidula Fornicata, Nicole L. Kleinas

Electronic Theses and Dissertations

The Atlantic slipper limpet, Crepidula fornicata, is a sequential hermaphrodite whose size at sex-change is plastic with respect to social and population cues. As an organism allocates energy between growth, reproduction and maintenance, an increased cost of one process may affect another. In this paper, I evaluate whether the presence of an epibiotic sponge (Cliona celata) affects the growth, condition and sex-change of C. fornicata individuals. Population surveys demonstrate a variable effect of Cliona presence on C. fornicata condition. The results of a twelve-week in situ experiment demonstrated a decrease in growth when C. celata was present. …


Distribution, Density, Movement, And Support For Management Of Mountain Sucker, Pantosteus Jordani, In The Black Hills Of South Dakota, Seth J. Fopma Jan 2020

Distribution, Density, Movement, And Support For Management Of Mountain Sucker, Pantosteus Jordani, In The Black Hills Of South Dakota, Seth J. Fopma

Electronic Theses and Dissertations

Mountain Sucker, Pantosteus jordani, is a cold-water species native to the Intermountain West. Fringe populations of Mountain Sucker have experienced declines in recent decades. The population of Mountain Sucker found in the Black Hills of South Dakota represents the eastern fringe of the species’ native range. Recognized as both an indicator of biologic health and as a species of greatest conservation need in South Dakota, recent studies have suggested significant declines in both distribution and abundance. Despite the recent study of Mountain Sucker in the region, increased understanding of Mountain Sucker ecology is needed to effectively manage for the conservation …


Scaling And Ecological Relationships In The Visual Ecology Of Sharks, Brianna Hall Jan 2020

Scaling And Ecological Relationships In The Visual Ecology Of Sharks, Brianna Hall

Electronic Theses and Dissertations

Adaptations of visual systems, such as acuity, sensitivity, and eye size can be used to infer the relative importance of vision to an organism. The high metabolic cost of visual system development and maintenance suggests that large relative eye size (as it relates to body length) may have a significant ecological or evolutionary role. Elasmobranchs are morphologically diverse and inhabit a wide range of marine and freshwater niches. As energetic and ecological demands shift over time, several species occupy different predatory niches across their lifetime, yielding a large array of visual habitats. Additionally, eye size changes with body length allometrically, …


Social-Ecological Heterogeneity Shapes Resilience Of Small-Scale Fisheries: An Interdisciplinary Analysis Of The Mexican Chocolate Clam Fishery In Loreto, Mexico, Kara E. Pellowe Aug 2019

Social-Ecological Heterogeneity Shapes Resilience Of Small-Scale Fisheries: An Interdisciplinary Analysis Of The Mexican Chocolate Clam Fishery In Loreto, Mexico, Kara E. Pellowe

Electronic Theses and Dissertations

All benefits provided by natural systems are embedded within coupled social-ecological systems (SESs). Fisheries are clear examples of SESs: through fishing, humans affect ecosystem structure and functioning, and in turn, receive benefits, including sustenance, employment, and cultural value. Resilience, the ability to maintain structure and function in the face of change, is key to sustaining the social and ecological components of fisheries-related SESs and their interactions. Many factors contribute to resilience, including heterogeneity. By identifying heterogeneity in these complex systems, we are better able to understand the capacity of fishery-related SESs to adapt to change, and contribute to management that …


Deep Benthic Coral Habitats Of Glacier Bay National Park And Preserve, Alaska, Elise C. Hartill Aug 2019

Deep Benthic Coral Habitats Of Glacier Bay National Park And Preserve, Alaska, Elise C. Hartill

Electronic Theses and Dissertations

Glacier Bay National Park and Preserve in Southeast Alaska is a system of fjords that presents an ideal natural laboratory to study terrestrial, aquatic and marine patterns of succession due to its unique and recent history of deglaciation. The patterns of deep benthic community assemblages in the fjords of Glacier Bay were investigated by quantitative assessment of underwater photo-quadrats collected using a remotely operated vehicle. The percent cover and diversity of species were lowest near the glaciated heads of the fjords and highest in the Central Channel and at the mouths of the fjords of Glacier Bay, where oceanographic conditions …


Response Of Early Life Stage Homarus Americanus To Ocean Warming And Acidification: An Interpopulation Comparison, Maura K. Niemisto Aug 2019

Response Of Early Life Stage Homarus Americanus To Ocean Warming And Acidification: An Interpopulation Comparison, Maura K. Niemisto

Electronic Theses and Dissertations

Anthropogenic carbon released into the atmosphere is driving rapid, concurrent increases in temperature and acidity across the world’s oceans, most prominently in northern latitudes. The geographic range of the iconic American lobster (Homarus americanus) spans a steep thermal gradient and one of the most rapidly warming oceanic environments. Understanding the interactive effects of ocean warming and acidification on this species’ most vulnerable early life stages is important to predict its response to climate change on a stage-specific and population level. This study compares the responses of lobster larvae from two sub-populations spanning New England’s north-south temperature gradient (southern …


Spatio-Temporal Dynamics Of Atlantic Cod Bycatch In The Maine Lobster Fishery And Its Impacts On Stock Assessment, Robert E. Boenish May 2018

Spatio-Temporal Dynamics Of Atlantic Cod Bycatch In The Maine Lobster Fishery And Its Impacts On Stock Assessment, Robert E. Boenish

Electronic Theses and Dissertations

Of the most iconic fish species in the world, the Atlantic cod (Gadus morhua, hereafter, cod) has been a mainstay in the North Atlantic for centuries. While many global fish stocks have received increased pressure with the advent of new, more efficient fishing technology in the mid-20th century, exceptional pressure has been placed on this prized gadoid. Bycatch, or the unintended catch of organisms, is one of the biggest global fisheries issues. Directly resulting from the failed recovery of cod in the GoM, attention has been placed as to possible sources of unaccounted catch. Among the most …


Polyp To Population: A Tale Of Two Corals, Christopher T. Fountain May 2018

Polyp To Population: A Tale Of Two Corals, Christopher T. Fountain

Electronic Theses and Dissertations

Deep-sea corals are of conservation concern in the North Atlantic due to prolonged disturbances associated with the exploitation of natural resources and a changing environment. As a result, the recovery rates of deep-sea coral communities are of heightened interest. These recovery rates are suggested to be on the order of decades to millennia, based on slow growth rates and longevity, of various deep-sea coral species. In 2014 and 2017 two research cruises in the Gulf of Maine, collected samples of two locally dominant species, Primnoa resedaeformis and Paramuricea placomus. These specimen collections were coupled with video surveys, conducted by …


Detrital Protein Contributes To Oyster Nutrition And Growth In The Damariscotta Estuary, Maine, Usa, Cheyenne M. Adams May 2018

Detrital Protein Contributes To Oyster Nutrition And Growth In The Damariscotta Estuary, Maine, Usa, Cheyenne M. Adams

Electronic Theses and Dissertations

Oyster aquaculture is an expanding industry that relies on identifying and utilizing natural estuarine conditions for the economically viable production of a filter-feeding crop. The eastern oyster, Crassostrea virginica, is the principal species currently cultured in Maine. In addition to preferentially consumed phytoplankton, various detrital complexes (non-algal and/or non-living organic matter) may provide some nutrition to C. virginica between times of phytoplankton abundance. Here I investigated the importance of detrital proteins in supporting the growth of oysters cultured in the upper Damariscotta Estuary. Oyster aquaculture in this area is highly successful and previous reports indicate that labile detrital protein …


Environmental Factors Affecting Hatch Success In The Loggerhead Sea Turtle (Caretta Caretta), Mattie J. Whitesell Jan 2018

Environmental Factors Affecting Hatch Success In The Loggerhead Sea Turtle (Caretta Caretta), Mattie J. Whitesell

Electronic Theses and Dissertations

The loggerhead turtle (Caretta caretta) is a species federally listed as “threatened” whose global populations are declining. Georgia Department of Natural Resources conservation protocols for this species require the daily monitoring of nesting activity and permit physical relocation of nests which are at risk of being eroded or flooded by storms and high tides in order to increase hatch success--the proportion of hatched to unhatched eggs. Relocated nests are moved to an area with higher elevation in order to avoid flooding, but other variables such as increased temperature and decreased moisture are introduced when relocating. For years temperature …


Lobster In A Changing Gulf Of Maine: Investigating The Temporal Impact On Molting And The Fishing Fleet, Kevin W. Staples Aug 2017

Lobster In A Changing Gulf Of Maine: Investigating The Temporal Impact On Molting And The Fishing Fleet, Kevin W. Staples

Electronic Theses and Dissertations

We investigated the phenological and fisheries dynamics surrounding the spring molt of American lobster (Homarus americanus, Milne Edwards 1847) in the Gulf of Maine. We created a time series from Maine Department of Marine Resources Lobster Sea Sampling data using logistic models to estimate the timing and duration of the spring molt for eastern, central, and western regions of the Maine coast. These estimates revealed substantial inter-annual variability in the timing of the spring molt for all regions and that 2012 was indeed anomalously early relative to other years. Each region experienced significantly different molt timing for any given …


Population Ecology Of Colonially Breeding Seabirds: How Intrinsic Processes, Mediating Influences, And Individual Heterogeneity Affect Population Vital Rates, Aly Mcknight May 2017

Population Ecology Of Colonially Breeding Seabirds: How Intrinsic Processes, Mediating Influences, And Individual Heterogeneity Affect Population Vital Rates, Aly Mcknight

Electronic Theses and Dissertations

Seabirds have great potential to serve as marine indicators. However, before we can interpret seabird trends with confidence, we need a better understanding of the role of intrinsic processes, mediating influences, and lifetime experience in modulating relationships between prey availability and seabird population dynamics.

Intrinsic processes, mediating influences, and seabird productivity. I assessed productivity (chicks per breeding attempt) at Black-legged Kittiwake (Rissa tridactyla) colonies in Prince William Sound, AK and managed Common Tern (Sterna hirundo) colonies in the Gulf of Maine. Both systems showed evidence of intrinsic control; factors mediating access to prey were also important.

Mediating influences, individual heterogeneity, …


Measuring Fertilization In Populations Of Sea Scallop (Placopecten Magellanicus): Developing And Testing Methods In The Laboratory And Field, Skylar Bayer May 2017

Measuring Fertilization In Populations Of Sea Scallop (Placopecten Magellanicus): Developing And Testing Methods In The Laboratory And Field, Skylar Bayer

Electronic Theses and Dissertations

Most marine organisms are broadcast spawners, releasing their sperm and eggs into the water column. Methods of measuring in situ fertilization have proven successful with a few model species, which are reviewed in my introductory chapter. However, many commercially exploited species, such as the sea scallop Placopecten magellanicus, have been neglected. Sea scallop populations have greatly increased from fishing closures, but the mechanism behind this response is uncertain, particularly in regard to fertilization. In this dissertation I developed a methodology of measuring fertilization success and spawning events of P. magellanicus, tested it in laboratory and field settings, and …


The Forgotten Cousin In Freshwater Community Ecology: Tidal Freshwater Wetlands, Jack R. Mclachlan Dec 2016

The Forgotten Cousin In Freshwater Community Ecology: Tidal Freshwater Wetlands, Jack R. Mclachlan

Electronic Theses and Dissertations

Tidal freshwaters are unique in their placement in the landscape, forming where freshwater riverine flows are sufficient to overwhelm the saline water of the incoming tide, but not strong enough to suppress tidal water-height fluctuations. Tidal freshwaters and their wetlands have been overlooked by freshwater and marine researchers alike; neither discipline considers tidal freshwaters to fall under their purview. Invertebrate communities in tidal freshwaters are thought to be species depauperate; the consensus is that they support fewer taxa than nearby non-tidal freshwaters, but little is known about how these communities are structured. This study investigated how tidal hydrology, an atypical …


Assessment Of A Hatchery Based Rainbow Smelt Supplementation Effort, Andrew O'Malley May 2016

Assessment Of A Hatchery Based Rainbow Smelt Supplementation Effort, Andrew O'Malley

Electronic Theses and Dissertations

Rainbow Smelt (Osmerus mordax) are an important fish distributed throughout northeastern North America with both anadromous and landlocked populations. Abundance, size at age, and maximum size vary widely among populations and life histories. In order to compare anadromous and landlocked populations, we collected spawning adults in 2014 from four anadromous and three landlocked populations. Scales and otoliths from the anadromous fish were examined and compared for estimates of bias and precision in ageing. Analysis of both scales and otoliths provided age estimates that were acceptable, but estimates from scales were more precise and had less bias. Otoliths were …