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Full-Text Articles in Life Sciences
Extending Aerial Surveys Beyond Target Marine Mammal Species: An Application Of Strip Transect Methodology To Humpback Whale And Dugong Abundance Estimation In Exmouth Gulf, Western Australia, Jennah Tucker
Theses : Honours
Aerial surveys are commonly used to estimate abundance of marine mammal populations, to detect trends over time and inform conservation management. Estimating abundance in areas critical to a species’ survival and reproduction is important to assess that population’s status and its vulnerability. Aerial surveys allow relatively large areas to be covered over short periods of time which can be important for highly mobile species with wide-ranging movement patterns such as marine mammals. While aerial surveys are often designed for specific target species, information on additional non-target species is often recorded, as surveys are generally infrequent due to expense and logistical …
Determination Of Atlantic Shortfin Mako Shark (Isurus Oxyrinchus) Population Genetic Structure And Comparison Of Mitogenomic Markers, Marissa Mehlrose
Determination Of Atlantic Shortfin Mako Shark (Isurus Oxyrinchus) Population Genetic Structure And Comparison Of Mitogenomic Markers, Marissa Mehlrose
All HCAS Student Capstones, Theses, and Dissertations
This study provides the first genomics-level, population structure and genetic diversity assessment of the shortfin mako (Isurus oxyrinchus) shark. The assessments were based on mitogenome sequences from makos distributed throughout the Atlantic Ocean, with Pacific mako mitogenomes used as a comparative outgroup. In addition to complete mitogenome-based analyses, I assessed individual mitochondrial coding gene and non-coding (Control Region) sequences for their comparative resolution properties as markers for revealing matrilineal population structure and genetic diversity. Sequencing of 125 makos in the western and eastern Atlantic across northern and southern hemispheres yielded 92 complete mitogenomes (16,698-16,702 bp) and 33 partial …
Historical Ecology Of The San Diego Sport Fishery: Catch Composition, Species Trends, And Fishing Effort From 1959 To 2011, Rebecca Schwartz Lesberg
Historical Ecology Of The San Diego Sport Fishery: Catch Composition, Species Trends, And Fishing Effort From 1959 To 2011, Rebecca Schwartz Lesberg
Theses
Like ocean systems around the world, species targeted by the San Diego sportfishery are subject to myriad threats from human activity, with several species already showing documented decline. However, long-term fisheries datasets are often lacking, limiting natural resource managers’ ability to appropriately manage these ecologically and economically important species. Therefore, this study used daily reports published in two Southern California newspapers to examine changes in catch composition, effort, and catch per unit effort (CPUE) from 1959-2011 for the San Diego commercial passenger fishing vessel (CPFV) sportfishery. This study then tested the relationship between those patterns and three large scale oceanographic …
Examining The Northern Shrimp Fishery In A Changing Gulf Of Maine, Ashley N. Charleson
Examining The Northern Shrimp Fishery In A Changing Gulf Of Maine, Ashley N. Charleson
Electronic Theses and Dissertations
Northern Shrimp (Pandalus borealis) once supported a key commercial fishery in the State of Maine. Since its closure in 2013, the stock has remained in a particularly vulnerable state following recruitment failure, overfishing, and rising water temperatures. Furthermore, without this source of supplemental income, local fishermen have also experienced financial stress following unstable fishing conditions in other fisheries. The collective goal of this research project was to assess factors impacting the feasibility of reopening and maintaining this vulnerable winter fishery. These goals are addressed over 4 chapters. Chapter two offers insight regarding what is most often omitted from the regulatory …
Pismo Clams (Tivela Stultorum) In Califorina: Population Status, Habitat Associations, Reproduction, And Growth, Alexandria R. Marquardt
Pismo Clams (Tivela Stultorum) In Califorina: Population Status, Habitat Associations, Reproduction, And Growth, Alexandria R. Marquardt
Master's Theses
Marine shellfish play a vital role in intertidal ecosystems and coastal communities, but many of these fisheries are small-scale and lack the necessary monitoring to ensure long-term sustainability. Effective management often requires information on key demographic parameters, such as population status, reproduction and growth. Pismo clams (Tivela stultorum) are a culturally important and iconic species in California, which supported a thriving commercial and recreational fishery throughout much of the 1900’s. However, Pismo clam populations have declined statewide in recent decades and are attributed to human harvest and predation by California sea otters (Enhydra lutris); However, no …
A Review Of The Global Commercial Cephalopod Fishery, With A Focus On Apparent Expansion, Changing Environments, And Management, Corey Clark
HCNSO Student Capstones
Cephalopods are both important predators and prey in many marine environments and important fishery resources in many countries. The global fishery has expanded almost continuously from landings of 580,000 metric tonnes in 1950 to over 4 m.t. in 2007. Cephalopods are ecological opportunists with highly plastic biological characteristics and varied population dynamics. Nearly all commercially harvested species are short-lived and can reproduce quickly, enabling them to evolve more rapidly under high selection pressure relative to many fish competitors and predators. As a result, they may have the biological means to be successful under conditions of long-term global climate change. This …
Reconciling The Challenge Of Aphanic Species Within Marine Conservation, Kerri L. Bolow
Reconciling The Challenge Of Aphanic Species Within Marine Conservation, Kerri L. Bolow
HCNSO Student Capstones
Aphanic species are those within a taxonomic complex that may not be readily distinguishable from other sympatric species. The existence of these species is becoming apparent at an increasing rate through the use of technological tools like molecular genetic analyses. A lack of clarity on the definitions of terms used to describe similar species, how these species are identified, and how prevalent they are can confound identification, description, and management of these organisms. This review collects and defines the terms used to describe these hidden species and suggests the use of the term aphanic for situations where additional information (and …
Life History Of The Non-Native Invasive Red Lionfish (Pterois Volitans) In The Northern Gulf Of Mexico, Alexander Q. Fogg
Life History Of The Non-Native Invasive Red Lionfish (Pterois Volitans) In The Northern Gulf Of Mexico, Alexander Q. Fogg
Master's Theses
Invasive Red Lionfish (Pterois volitans) were first detected in the northern Gulf of Mexico (nGOM) in 2010 and since then their numbers have increased dramatically. From 2010 to 2015, more than 15,000 Red Lionfish were collected opportunistically from the nGOM for this study. Length and weight relationships differed significantly among ecoregions by sex and there was clear sexual dimorphism in size with males being larger and heavier. Red Lionfish age ranged from 0-4.5 years old and males achieved greater growth rate (K) and asymptotic maximum lengths (Linf) compared to females and these parameters were also different …
Management Recommendations For Restoration Of The Degraded Olympia Oyster, Ostrea Lurida Carpenter 1864 In Tomales Bay, Ca, Carolyn M. Gibson
Management Recommendations For Restoration Of The Degraded Olympia Oyster, Ostrea Lurida Carpenter 1864 In Tomales Bay, Ca, Carolyn M. Gibson
Master's Projects and Capstones
This research addresses the effective restoration of Olympia oyster populations in Tomales Bay, Marin County, California. Chapter 2 provides background information on the Tomales Bay estuary, regional history, and ecology of the Olympia oyster. Following this background discussion, each of the three aforementioned degraders of Olympia oyster populations in Tomales Bay is presented: ocean acidification (Chapter 3), sedimentation (Chapter 4), and invasive species (Chapter 5). Each of these issues creates numerous barriers that require the attention of resource protection managers. Chapter 6 presents overall Research Conclusions and Chapter 7 identifies management recommendations to effectively begin the restoration of the Olympia …
Seasonal Warm-Water Refuge And Sanctuary Usage By The Florida Manatee (Trichechus Manatus Latirostris) In Kings Bay, Citrus County, Florida, Danielle C. Sattelberger
Seasonal Warm-Water Refuge And Sanctuary Usage By The Florida Manatee (Trichechus Manatus Latirostris) In Kings Bay, Citrus County, Florida, Danielle C. Sattelberger
HCNSO Student Theses and Dissertations
The largest Florida manatee (Trichechus manatus latirostris) aggregation at a natural warm-water refuge occurs in Kings Bay, Crystal River, FL. Over the last 32 years, the U.S. Fish and Wildlife Service and the State of Florida have created a network of manatee protection areas within Kings Bay including a year-round refuge designation and seven Federal manatee sanctuaries during the winter manatee season (November 15 – March 31). Aerial survey data collected between 1983 and 2012 was used to examine the seasonal change in manatee distribution within Kings Bay in order to assess the effectiveness of current sanctuary sizes …
Global Population Structure Of The Dusky Shark And Geographic Sourcing Of Shark Fins From Commercial Markets, Teagen K. Gray
Global Population Structure Of The Dusky Shark And Geographic Sourcing Of Shark Fins From Commercial Markets, Teagen K. Gray
HCNSO Student Theses and Dissertations
The dusky shark, Carcharinus obscurus, is a globally distributed, coastal-pelagic species subject to an apparent high level of exploitation. The International Union for the Conservation of Nature (IUCN) lists this species as “Vulnerable” globally, and “Endangered” within western North Atlantic and Gulf of Mexico waters due to an over 80% decline in this region, with no evidence of population recovery. The extensive exploitation of dusky sharks may partly be attributed to the high market value of its fins, but the contribution of individual dusky shark stocks to the fin markets is unknown. This knowledge would be helpful to detect …
Molecular Ecology Of Globally Distributed Sharks, Christine B. Testerman
Molecular Ecology Of Globally Distributed Sharks, Christine B. Testerman
HCNSO Student Theses and Dissertations
Many sharks have life history characteristics (e.g., slow growth, late age at maturity, low fecundity, and long gestation periods) that make their populations vulnerable to collapse due to overfishing. The porbeagle (Lamna nasus), bull shark (Carcharhinus leucas), great hammerhead (Sphyrna mokarran), and smooth hammerhead (S. zygaena), are all commercially exploited. The population genetic structure of these species was assessed based on globally distributed sample sets using mitochondrial control region (mtCR) sequences and/or nuclear markers. Complex patterns of evolutionary and demographic history were inferred using coalescent and statistical moment-based methods. All four species showed …