Aquaculture and Fisheries Commons^™

The Influence Of Range Shifts And Wind Energy On The Atlantic Surfclam (Spisula Solidissima) And Ocean Quahog (Arctica Islandica) Fisheries On The U.S. Outer Continental Shelf, Stephanie Stromp

Master's Theses

The Atlantic surfclam, Spisula solidissima, is a biomass dominant bivalve of the Northwestern Atlantic. The surfclam’s historic range extended from Cape Hatteras to Georges Bank, but recent decades of warming bottom water temperatures have caused the surfclam to shift its range to cooler waters north and offshore within the range of the ocean quahog, Arctica islandica. An ecotone now exists over much of the offshore range of the surfclam in which surfclams and ocean quahogs co-occur. Regulations prohibit fishers from landing both species in the same catch, limiting fishing to locations where the target species can be sorted …

Sensitivity Of A Lamp Assay For Detection Of The Dinoflagellate Amyloodinium Ocellatum In Simulated Field Conditions And Freeze Tolerance Of The Parasite, Robert Gonzales

Master's Theses

The obligate parasitic dinoflagellate Amyloodinium ocellatum causes amyloodiniosis in warm water marine fishes. The prolific parasite, which has a direct, three-stage life cycle, is highly infectious and can cause heavy losses in aquaculture. Prevention, biosecurity, and early detection are vital for control. In this work, microscopy and a loop-mediated isothermal amplification (LAMP) assay were compared for early diagnosis of A. ocellatum in cultured stocks, and the freeze tolerance of tomonts was assessed to determine if frozen wild fish used as fish food can serve as a potential vector for the parasite.

The lowest dinospore concentration that could be detected by …

Trophic Ecology Of Mesopelagic Fish Larvae And Juveniles In The Northern Gulf Of Mexico, Emily Gipson

Master's Theses

The deep-pelagic environment encompasses ocean waters below 200 m depth, and comprises 90% of the volume of the Gulf of Mexico. Deep-pelagic fishes are important prey for many oceanic consumers, but relatively little is known about their early life history, including larval fish trophic ecology. An understanding of the role deep-pelagic fish larvae have in oceanic food webs is important in the development of ecosystem models that examine the connectivity (via vertical migrations) between the deep-pelagic and epipelagic environments with respect to trophic interactions, nutrient cycling, and carbon sequestration. In this study, archived plankton samples collected during 2010 and 2011 …

Microplastic Abundance, Distribution And Impacts On Sargassum-Associated Juvenile Fishes In The Gulf Of Mexico, Olivia Lestrade

Master's Theses

Microplastics are a concern in marine environments because they are highly durable, ubiquitous, and can be mistaken for food and ingested by small organisms. Pelagic Sargassum, an important habitat for larval and juvenile stages of many fish species, is found in large surface aggregations, and may provide complex structure in which microplastics become trapped. This could lead to greater risk of microplastic ingestion by fish early life stages associated with Sargassum habitats. To better understand the impacts of microplastics within Sargassum communities, this study examined 1) microplastic concentrations and ingestion by juvenile fishes associated with Sargassum; 2) the microbial …

Assessing The Nursery-Role Function Of Pelagic Sargassum For Juvenile Fishes In The Northern Gulf Of Mexico, Courtney Stachowiak

Master's Theses

Sargassum, a genus of holopelagic brown algae, floats at the ocean’s surface using air-filled bladders and forms a complex comprised of two species, S. natans and S. fluitans. Oceanic processes (e.g., Langmuir circulation, etc.) aggregate Sargassum into mats and weedlines, and primarily distribute the algal complex throughout the North Atlantic Ocean and the Gulf of Mexico (GOM). These floating habitats provide shelter and feeding opportunities for a diverse community of invertebrates and fishes. Sargassum is a presumed nursery habitat for juvenile stages of commercially- and recreationally-targeted fishery species. In this study, I estimated the standardized abundances of juvenile …

Determining The Trophic Role Of Red Snapper (Lutjanus Campechanus) In Mississippi State Waters Using Stomach Content And Stable Isotope Analysis, Branden Kohler

Master's Theses

The goal of this study was to determine the diet composition, trophic position and ecological role of red snapper (Lutjanus campechanus) in Mississippi state waters utilizing stable isotopes (δ¹³C and δ¹⁵N) and stomach content analysis. Stable isotope analysis of fish and their prey can provide information on species-specific basal resource utilization, diet composition and trophic position which can improve food web models and inform fisheries management decisions. Particulate organic matter (POM), the presumed base of the food web, red snapper muscle tissue, and red snapper stomach contents were collected from 25 sites in 2016 and …

Maturation Spawning And Larviculture Of Atlantic Croaker (Micropogonias Undulatus) At Low Salinity, Edithrose Fairweather

Master's Theses

Atlantic Croaker is a popular baitfish among anglers targeting a variety of gamefish in the Gulf of Mexico. Aquaculture of this species could help meet the demand for Croaker, especially during winter when wild-caught Croaker are unavailable. Currently, Croaker aquaculture involves broodstock maturation, spawning, and larval culture at high salinity. This protocol prevents the direct use of coastal water for culture along the Mississippi Gulf coast where salinity is low. This study examined the feasibility of performing hatchery production of Atlantic Croaker at low salinity.

Culture of Croaker broodstock at 10, 20, and 30 psu during the maturation period was …

An Analysis Of Dredge Efficiency For Surfclam And Ocean Quahog Commercial Dredges, Leanne Poussard

Master's Theses

Between 1997 and 2011, The National Marine Fisheries Service conducted 50 depletion experiments to estimate survey gear efficiency and stock density for Atlantic surfclam (Spisula solidissima) and ocean quahog (Arctica islandica) populations using commercial hydraulic dredges. The Patch Model was formulated to estimate gear efficiency and organism density from the data. The range of efficiencies estimated is substantial, leading to uncertainty in the application of these estimates in stock assessment. Analysis of depletion experiment simulations showed that uncertainty in the estimates of gear efficiency from depletion experiments was reduced by higher numbers of dredge tows per experiment, more tow overlap …

The Effects Of Salinity On Zootechnical Performance Of Spotted Seatrout (Cynoscion Nebulosus) In Recirculating Aquaculture Systems, Eric Gigli

Master's Theses

The spotted seatrout (Cynoscion nebulosus) is a euryhaline finfish candidate for marine aquaculture in the northern Gulf of Mexico. Aquaculture of this species currently uses salinities of 25 psu or greater making production challenging in areas where high salinity water is not available. This study aimed to document the effects of salinity on zootechnical performance of spotted seatrout embryos, early larvae, and juveniles in recirculating aquaculture systems to assist with the development of protocols for low salinity culture.

Embryos obtained from a volitional spawn at 29 psu were incubated at three salinities (12.5, 18.75, or 25 psu) until …

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 (L_inf) compared to females and these parameters were also different …

Bloom Or Bust: Retrospective Analysis Of The Giant Jellyfish, Nemopilema Nomurai (Scyphozoa: Rhizostomeae), Ecology In The East Asian Marginal Seas, Naomi Yoder

Master's Theses

The Giant Jellyfish, Nemopilema nomurai, is a large-bodied bloom-forming jellyfish that occurs in the semi-enclosed basins of the East Asian Marginal Seas. N. nomurai has bloomed more frequently in the past 20 years than in any period previously recorded. In Japan, recent N. nomurai blooms were responsible for millions of dollars in lost revenue and equipment damage to commercial fisheries alone. This study statistically analyzed 21 environmental factors in connection with N. nomurai occurrence (using occurrence as a proxy for blooms). Eight factors resulted in a statistically significant or marginally significant (p ≤ 0.10), linear or non-linear relationship with …

Growth And Reproduction Of Southern Flounder (Paralichthys Lethostigma) In The North-Central Gulf Of Mexico, Morgan Marie Corey

Master's Theses

Southern Flounder Paralichthys lethostigma is the most commonly harvested flatfish in the north-central Gulf of Mexico (GOM) and supports a major inshore recreational fishery, yet knowledge of the species’ life history is greatly limited. The objective of this research was to describe the growth and reproduction of Southern Flounder in the Mississippi stock. Fish were collected during September 2014 to March 2016 using primarily recreational fishing techniques. Otoliths (n = 313) were sectioned to estimate age, and multiple length-at-age models were fit to total length (TL, mm) and age estimate (y) data. Gonadal tissue samples (n = 221) …

Development Of Genomic Resources For The Evaluation Of Red Snapper, An Emerging Species Candidate For Marine Aquaculture And Stock Enhancement, Adrienne Elise Norrell

Master's Theses

The northern red snapper (Lutjanus campechanus) is a highly targeted reef fish candidate for marine aquaculture and stock enhancement in the southern United States. This work aimed to develop genomic resources for the genetic management of aquaculture programs and to investigate population structure using high-throughput sequencing technologies. Eighty-four new microsatellite markers were developed through screening of Illumina paired-end sequencing reads. Microsatellite loci and Single Nucleotide Polymorphisms (SNPs) generated through Restriction Site Associated DNA (RAD) sequencing were assayed in 5 outbred full-sib families to construct a high-density linkage map of the red snapper genome. The map consists of 7,964 …

Effects Of Pre-Release Physical Stressors On Post-Release Success Of Hatchery-Reared Spotted Seatrout, Taylor Westbrook Guest

Master's Theses

Alteration of habitat associated with coastal development and increased demand for food and recreation can result in the depletion of fisheries resources such as the Spotted Seatrout (Cynoscion nebulosus), the Gulf of Mexico’s most popular recreational fish. Stock enhancement, or the release of cultured fish to supplement wild populations, is one potential tool for managing important fisheries resources. Although much effort has gone into marine stock enhancement, the effectiveness of stocking is not well established, and techniques for ensuring success have not been developed. Although the basic biology of the Spotted Seatrout is well known, comparatively little is known about …

Reproductive Life History Of Fundulus Jenkensi And Comparative Development Of Five Sympatric Fundulid Species, Eric Thomas Lang

Master's Theses

Fundulus jenkinsi is recognized federally and within the state of Mississippi as a Species of Concern. Little is known about the life history of this coastal killifish, but a detailed reproductive histology study of F. jenkinsi and a diagnostic key of the early life stages of select members of Fundulidae can provide the foundation needed to accurately identify it and quantify reproductive parameters in this rare species in need of conservation. Monthly gonadosomatic index (GSI) of male and female F. jenkinsi were documented, and spawning phases and oocyte stages were examined using reproductive histology. In addition, various stages of …

Fecundity And Survival Of The Calanoid Copepod Acartia Tonsa Fed Isochrysis Galeana (Tahitian Strain) And Chaetoceros Mulleri, Angelos Apeitos

Master's Theses

Historically, red snapper (Lutjanus campechanus) larviculture at the Gulf Coast Research Lab (GCRL) used 25 ppt artificial salt water and mixed, wild zooplankton composed primarily of Acartia tonsa, a calanoid copepod. Acartia tonsa was collected from the estuarine waters of Davis Bayou and bloomed in outdoor tanks from which it was harvested and fed to red snapper larvae. We are developing a more controlled copepod mass culture system to support finfish larviculture. To that end, I examined the effect of single species versus mixed species of algae as food for the copepods. Wild A. tonsa were isolated and reared in …