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Phosphate Groove: Unlocking the Rhythms of Sedimentary Deposits in the Kickamuit and Taunton Rivers
No full textPhosphorus can be found in many different forms (organic and inorganic), in soils, water bodies, and ocean sediments (Franson and Jones, 2007). All living organism utilizes phosphorus in numerous metabolic cycles and as structural motifs (Downing et al. 2000). The bioavailability of phosphorus, a limiting nutrient in the environment determines the successful growth of organisms, having a significant impact on primary production, species distribution, and ecosystem structure (Ferrier-Pages et al., 2016). Freshwater deposition of free phosphorus ions occurs upon mixing with alkaline saline waters into marine sediments thus becoming a reservoir for loose and tightly bound forms that can be ecologically recycled within this niche.
In this investigation, the concentration of total phosphate, inorganic phosphate, organic phosphate, and water-soluble phosphate was determined from pore waters extracted from Mt. Hope Bay marine core sediments. Surface water, filtered pore water samples, as well as extruded dried sediment segmented samples were analyzed for their salinity, pH, conductivity, nitrate, nitrite, and sulfate, via HACH® protocols. Elemental analysis by ICP and XRF spectroscopy were conducted following established methods. This study shows that as total organic sediment carbon increases, total phosphate content increases. Pore water-soluble phosphate increases with depth from the surface of the core. No relationship was determined for the ratio of bond inorganic phosphorus to iron, remaining relatively constant with the analysis. The pH of pore water becomes more alkaline with an increase in depth from the surface. This is also reflected in the change observed in nitrate and nitrite content going from an aerobic to an anoxic environment with increasing depth
Molecular Assessment of Green and Brown Algal Diversity of the Punta Burica Peninsula, Pacific Panama
No full textPunta Burica is a small peninsula off the Pacific coast of Panama that is characterized by an intriguing mudrock substratum. This substratum supports diverse populations of macroscopic algae by virtue of creating pools for them to inhabit and by retaining water within the substratum, which appears to minimize desiccation for attached algae. The Punta Burica region has been poorly studied phycologically, but the first study of the region revealed some 20 new records from just 45 specimens of red algae. Here, we extend our understanding of the Pacific Panama marine flora by using DNA barcoding to establish the species richness of brown and green algae of the Punta Burica peninsula
Addressing microplastic environmental data gaps through undergraduate research
Get PDFPlastic pollution from freshwater and atmospheric sources into coastal and marine environments is complex and the extent is largely unquantified. Such a gap in knowledge of marine microplastic sources, fate, and transport requires a spectrum of engineers and scientists, so that technical, social, and policy solutions can be developed. Citizen scientists are low cost and can collect an abundance of field data. Experienced scientists can complete costly but advanced analytical analyses on a smaller sample of plastics. This project engages engineering and science undergraduate students (moderate experience) in microplastic data collection and analysis to fill gaps in microplastic data for the state of Rhode Island. Methods were developed to collect and analyze local river and atmospheric data. River samples were collected from a range of urban and rural sample sites. Atmospheric samples were collected by dry deposition into a custom-designed stainless steel collector located on campus. Nile red dye was used to stain the samples, which were then visually enumerated by fluorescence using a retrofitted compound microscope. All samples contained microplastics and suspected microplastics (as identified by visual analysis). Rural freshwater samples contained fewer average pieces per liter than the more urban samples. Atmospheric deposition of microplastic fibers on the moderately urban campus site was within the ranges (fibers per square meters per day) reported in other urban locations globally. Continued data collection by the undergraduate student team in collaboration with a variety of local partners from citizen scientists to experts in the field is required to develop a robust understanding of the abundance, distribution, fate, and transport of plastics in the state of Rhode Island to mitigate inputs and impacts to the Narragansett Bay
The use of age and growth techniques to quantify the age structure of carryover hybrid catfish (female Channel Catfish × male Blue Catfish) in commercial ponds in West Alabama
No full textObjective: In West Alabama, catfish Ictalurus spp. producers routinely face the challenge of fish that exceed market size (aka “Big Fish”) in their commercial ponds. These fish are skilled at evading seine nets during harvest and can increase in size significantly before subsequent harvests occur. This is problematic for catfish producers because processing plants prefer catfish within the 0.45–1.81-kg range and farmers are paid a premium price for catfish of this size. Due to their larger size and growth potential, hybrid catfish (female Channel Catfish Ictalurus punctatus × male Blue Catfish I. furcatus) can become a more significant issue than Channel Catfish if they evade harvest. The objective of this study was to describe and quantify the age structure and growth rate of hybrid catfish that evade capture and remain in commercial ponds following harvest and grow beyond acceptable market size as defined by catfish processing plants (i.e., Big Fish). Methods: Hybrid catfish were collected from 12 recently harvested commercial ponds in West Alabama from December 2021 to August 2022 using an electroshocking boat. Total length (mm), body weight (kg), and sex of collected fish were recorded, and lapilli otoliths were removed to estimate fish age and determine total length and total body weight at estimated ages. Result: In this study, 1005 hybrid catfish were collected with the successful age estimation for 1001 catfish, ranging from 1 to 11 years. Results of this study indicate that hybrid catfish exceeded the premium size threshold in 2.72 years ± 8 months. Additionally, from age 2 to age 3, the average hybrid catfish gained 2.90 kg, growing from 0.40 to 3.30 kg. Growth rate was significantly affected by sex; males overall were predicted to weigh more than females based on the weight-at-age model. Conclusion: Hybrid catfish should be completely harvested from commercial ponds following 1 year of harvest to receive the premium price per kilogram of live fish. If a complete harvest is unsuccessful, farmers can receive a discounted price per kilogram of leftover hybrid catfish based on current market trends
Thraustochytriidae infections of bivalves
No full textOrganisms making up the phylum, Labyrinthulomycota, usually termed slime molds, are rarely parasites of marine animals, but two in the family Thraustochytriidae have been identified as pathogens of bivalves. Ruditapes decussatus (grooved carpet shell clam) is infected by a thraustochytriidae causing ulceration and local infection of the gills. Quahog Parasite Unknown (QPX), recently named Mucochytrium quahogii, has been investigated extensively and can be the cause of significant disease and associated mortality in cultured and wild hard clams (Mercenaria mercenaria) on the east coast of the US and Canada. QPX invades the mantle tissues primarily at a site adjacent to the incurrent siphon and can spread from there to the internal tissue of the body. Hard clam inflammation responding to QPX infection varies in intensity between spring and summer seasons in this ectothermic animal, results in an apparently ineffective inflammatory response in the spring and a usually high spring mortality. Hard clam strain, based on historical origin of the broodstock, has a significant effect on development of disease with seed of strains from southern areas exhibiting more severe disease when cultured in northern areas. Ongoing research is identifying genes responsible for resistance that can be used to screen potential hard clam broodstock
The slap heard round the world: Using live televised award-show incidents to teach expectancy violations theory
No full textThis activity provides students with a way of understanding expectancy violations theory (EVT) by examining incidents that occurred during televised award shows. In this activity, in small groups, students will delve into well-known award-show incidents, such as Will Smith’s slapping of Chris Rock at the 2022 Academy Awards, to understand the events leading up to the incident, what happened at the time of the event, and the repercussions occurring after. Using this information, students will work through the components of EVT to enhance their understanding of the theory and its lens through which to view relationships. This activity allows students to use their familiarity with pop culture to gain a greater understanding of EVT in order to better utilize the theory when examining their own interpersonal relationships. Courses: Introduction to Mass Media Communication, Interpersonal Communication, Mass Media Theory and Criticism, Organizational Communication. Objectives: Students will understand the principles of EVT; be able to explain EVTs components (expectancy, communicator reward valance, and violation valence); and be able to apply EVT to examples of interpersonal interactions
Higher Order Mode Analysis in Frequency Selective Negative Curvature Fibers
No full textA novel negative curvature hollow-core fiber is numerically designed capable of filtering specific frequencies. The six-tube silica fiber strongly favors fundamental mode transmission over higher order modes despite uneven positioning of cladding elements
