In the past 80 years, Louisiana has lost over one million acres in land, affecting plants and crustaceans that live in these environments. The first objective of this research was to determine the relationship between...In the past 80 years, Louisiana has lost over one million acres in land, affecting plants and crustaceans that live in these environments. The first objective of this research was to determine the relationship between diffused oxygen in water and time with the behavioral and physiological health of Callinectes sapidus (blue crab) and Procambarus clarkii (crawfish). After 24 hours, manual dexterity, or the amount of time it takes for a crustacean to flip itself over increased under hypoxic conditions. Hemolymph was extracted and tested for lactate, glucose, and protein. Crawfish were also exposed to this same procedure. An additional crawfish study comparing Spartina plants to assimilate oxygen for aeration compared to mechanical aeration was conducted. The hypoxic groups for all three studies at the 0.05 level had a significantly greater manual dexterity time and greater amounts of lactate and glucose. The protein was significantly higher in hypoxia-exposed crawfish. Time and aeration affect the health of crustaceans, and plants were shown to effectively provide normoxic oxygen levels at a similar level as mechanical aeration. These studies support the importance of marsh grasses for the coast and crustacean viability.展开更多
Coastal erosion, subsidence, salt water intrusion, and hypoxia are forces that impact Louisiana and beyond. The objective of this research was to determine the extent of land loss due to erosion and establish the best...Coastal erosion, subsidence, salt water intrusion, and hypoxia are forces that impact Louisiana and beyond. The objective of this research was to determine the extent of land loss due to erosion and establish the best Spartina (S.) species to ameliorate the coast. Using graph theory in the Geometer’s Sketch Pad program, progressive land loss from Isles Dernieres was determined from 1853 to 2005. This was accomplished using Pick’s Theorem (A = I + B/2 - 1), where A = total land area, I = interior intersections, and B = boundary intersections. The analysis indicated that there had been more than ninety percent land loss from 1853 to 2005. Additionally, four plants from each Spartina species (alterniflora, patens, and spartinae) were planted and flooded in four containers, respectively, filled with potting soil, and a non-vegetated control was included in this same manner. Dissolved oxygen was measured three times a week under three different temperature regimes, twenty-two, thirty, and ten degrees Celsius, respectively. This resulted in the control group diffusing the most oxygen at twenty-two degrees Celsius, the S. alterniflora diffusing the most oxygen at thirty degrees Celsius, and all the species diffusing statistically similar oxygen levels at ten degrees Celsius. After six months of flooded conditions, penetration and subsidence were measured. The vegetated soils required the greatest penetration forces and subsided the least. Oxygen diffusion is dependent on plant species and temperature. The penetration and subsidence results also support the conclusion that plants can reduce land loss and preserve the coastline.展开更多
文摘In the past 80 years, Louisiana has lost over one million acres in land, affecting plants and crustaceans that live in these environments. The first objective of this research was to determine the relationship between diffused oxygen in water and time with the behavioral and physiological health of Callinectes sapidus (blue crab) and Procambarus clarkii (crawfish). After 24 hours, manual dexterity, or the amount of time it takes for a crustacean to flip itself over increased under hypoxic conditions. Hemolymph was extracted and tested for lactate, glucose, and protein. Crawfish were also exposed to this same procedure. An additional crawfish study comparing Spartina plants to assimilate oxygen for aeration compared to mechanical aeration was conducted. The hypoxic groups for all three studies at the 0.05 level had a significantly greater manual dexterity time and greater amounts of lactate and glucose. The protein was significantly higher in hypoxia-exposed crawfish. Time and aeration affect the health of crustaceans, and plants were shown to effectively provide normoxic oxygen levels at a similar level as mechanical aeration. These studies support the importance of marsh grasses for the coast and crustacean viability.
文摘Coastal erosion, subsidence, salt water intrusion, and hypoxia are forces that impact Louisiana and beyond. The objective of this research was to determine the extent of land loss due to erosion and establish the best Spartina (S.) species to ameliorate the coast. Using graph theory in the Geometer’s Sketch Pad program, progressive land loss from Isles Dernieres was determined from 1853 to 2005. This was accomplished using Pick’s Theorem (A = I + B/2 - 1), where A = total land area, I = interior intersections, and B = boundary intersections. The analysis indicated that there had been more than ninety percent land loss from 1853 to 2005. Additionally, four plants from each Spartina species (alterniflora, patens, and spartinae) were planted and flooded in four containers, respectively, filled with potting soil, and a non-vegetated control was included in this same manner. Dissolved oxygen was measured three times a week under three different temperature regimes, twenty-two, thirty, and ten degrees Celsius, respectively. This resulted in the control group diffusing the most oxygen at twenty-two degrees Celsius, the S. alterniflora diffusing the most oxygen at thirty degrees Celsius, and all the species diffusing statistically similar oxygen levels at ten degrees Celsius. After six months of flooded conditions, penetration and subsidence were measured. The vegetated soils required the greatest penetration forces and subsided the least. Oxygen diffusion is dependent on plant species and temperature. The penetration and subsidence results also support the conclusion that plants can reduce land loss and preserve the coastline.
