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Full-Text Articles in Life Sciences

Preservation Of Atp In Hypersaline Environments, Bruce J. Tuovila, Fred C. Dobbs, Paul A. Larock, B. Z. Siegel Dec 1987

Preservation Of Atp In Hypersaline Environments, Bruce J. Tuovila, Fred C. Dobbs, Paul A. Larock, B. Z. Siegel

OES Faculty Publications

High concentrations of particulate ATP were found in the anoxic brines of the Orca Basin and East Flower Garden, Gulf of Mexico. Other measurements indicative of growth and respiration suggested that the microbial community in the brines was inactive, but somehow the ATP associated with the cells persisted. Conceivably, when cells growing just above the interface sank into the brine, the increased osmotic stress could elicit an osmoregulatory response resulting in increased ATP. It was also possible that hydrolytic enzymes were inactivated, resulting in the preservation of ATP. Experiments in which a culture of marine bacteria was suspended in menstrua …


Validation Of The Otolith Increment Aging Technique For Striped Bass, Morone Saxatilis, Larvae Reared Under Suboptimal Feeding Conditions, Cynthia Jones, Edward B. Brothers Jan 1987

Validation Of The Otolith Increment Aging Technique For Striped Bass, Morone Saxatilis, Larvae Reared Under Suboptimal Feeding Conditions, Cynthia Jones, Edward B. Brothers

OES Faculty Publications

Striped bass, Morone saxatilis, larvae were reared in the laboratory for 97 days to validate the otolith increment aging technique for this species. Otolith-increment deposition rates were determined under optimal laboratory conditions for growth and under three conditions of restricted feeding and using both light and scanning electron microscopy (SEM). Under optimal laboratory conditions. increments were deposited daily from the fourth day after hatching through the first 2 months of life and were discernible with the light microscope. For larvae reared under restricted feeding regimes and readings done with the light microscope, counts did not reflect true age. Counts …


Acceleration Of Nutrient Uptake By Phytoplankton In A Coastal Upwelling Ecosystem: A Modeling Analysis, Richard C. Zimmerman, James N. Kremer, Richard C. Dugdale Jan 1987

Acceleration Of Nutrient Uptake By Phytoplankton In A Coastal Upwelling Ecosystem: A Modeling Analysis, Richard C. Zimmerman, James N. Kremer, Richard C. Dugdale

OES Faculty Publications

Studies of upwelling centers in the eastern Pacific suggest that maximum rates of nitrate uptake (light and nutrient saturated) increase, or shift-up, as newly upwelled water moves downstream. The rate of shift-up appears to be related to irradiance and the ambient concentration of limiting nutrient at the time of upwelling. A mathematical model was developed to evaluate effects of irradiance and initial nitrate concentration on temporal patterns of shift-up and subsequent time scales of nutrient utilization over a range of simulated upwelling conditions. When rates consistent with field studies were used, complete shift-up was possible only under certain conditions, and …


Is Growth Of Eelgrass Nitrogen Limited? A Numerical Simulation Of The Effects Of Light And Nitrogen On The Growth Dynamics Of Zostera Marina, Richard C. Zimmerman, Robert D. Smith, Randall S. Alberte Jan 1987

Is Growth Of Eelgrass Nitrogen Limited? A Numerical Simulation Of The Effects Of Light And Nitrogen On The Growth Dynamics Of Zostera Marina, Richard C. Zimmerman, Robert D. Smith, Randall S. Alberte

OES Faculty Publications

A numerical model of nitrogen uptake and growth was developed for the temperate seagrass Zostera marina L. Goals were to evaluate the relative effects of light and nitrogen availability on nitrogen uptake and partitioning between leaf and root tissue, and to estimate nitrogen concentrations in the sedment and water column required to saturate growth. Steady-state predictions are quite robust with respect to a range of parameter values justified by available data The calculations indicated that roots are probably more important in overall nitrogen acquisition in most light and nitrogen environments encountered in situ, but may contribute less than 50 …