Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 18 of 18
Full-Text Articles in Physical Sciences and Mathematics
Saturating Growth Rate Against Phosphorus Concentration Explained By Macromolecular Allocation, Gabrielle Armin, Jongsun Kim, Keisuke Inomura
Saturating Growth Rate Against Phosphorus Concentration Explained By Macromolecular Allocation, Gabrielle Armin, Jongsun Kim, Keisuke Inomura
School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations
The saturating relationship between phytoplankton growth rate and environmental nutrient concentration has been widely observed, yet the mechanisms behind the relationship remain elusive. Here, we use a mechanistic model of phytoplankton and show that the saturating relationship between growth rate and phosphorous concentration can be interpreted by intracellular macromolecular allocation. At low nutrient levels, the diffusive nutrient transport linearly increases with the phosphorous concentration, while the internal phosphorous requirement increases with the growth rate, leading to a non-linear increase in the growth rate with phosphorous. This increased phosphorous requirement is due to the increased allocation to biosynthetic and photosynthetic molecules. …
Potential Interactions Between Diatoms And Bacteria Are Shaped By Trace Element Gradients In The Southern Ocean, Alexa R. Sterling, Laura Z. Holland, Randelle M. Bundy, Shannon M. Burns, Kristen N. Buck, P. Dreux Chappell, Bethany D. Jenkins
Potential Interactions Between Diatoms And Bacteria Are Shaped By Trace Element Gradients In The Southern Ocean, Alexa R. Sterling, Laura Z. Holland, Randelle M. Bundy, Shannon M. Burns, Kristen N. Buck, P. Dreux Chappell, Bethany D. Jenkins
OES Faculty Publications
The growth of diatoms in the Southern Ocean, especially the region surrounding the West Antarctic Peninsula, is frequently constrained by low dissolved iron and other trace metal concentrations. This challenge may be overcome by mutualisms between diatoms and co-occurring associated bacteria, in which diatoms produce organic carbon as a substrate for bacterial growth, and bacteria produce siderophores, metal-binding ligands that can supply diatoms with metals upon uptake as well as other useful secondary compounds for diatom growth like vitamins. To examine the relationships between diatoms and bacteria in the plankton (diatom) size class (> 3 mu m), we sampled both …
The Atlantic Surfclam Fishery And Offshore Wind Energy Development: 1. Model Development And Verification, Daphne M. Munroe, Eric N. Powell, John M. Klinck, Andrew M. Scheld, Sarah Borsetti, Jennifer Beckensteiner, Eileen E. Hofmann
The Atlantic Surfclam Fishery And Offshore Wind Energy Development: 1. Model Development And Verification, Daphne M. Munroe, Eric N. Powell, John M. Klinck, Andrew M. Scheld, Sarah Borsetti, Jennifer Beckensteiner, Eileen E. Hofmann
CCPO Publications
Competing pressures imposed by climate-related warming and offshore development have created a need for quantitative approaches that anticipate fisheries responses to these challenges. This study used a spatially explicit, ecological-economic agent-based model integrating dynamics associated with Atlantic surfclam stock biology, decision-making behavior of fishing vessel captains, and fishing fleet behavior to simulate stock biomass, and fishing vessel catch, effort and landings. Simulations were implemented using contemporary Atlantic surfclam stock distributions and characteristics of the surfclam fishing fleet. Simulated distribution of fishable surfclam biomass was determined by a spatially varying mortality rate, fishing by the fleet was controlled by captain decisions …
Saturating Relationship Between Phytoplankton Growth Rate And Nutrient Concentration Explained By Macromolecular Allocation, Jongsun Kim, Gabrielle Armin, Keisuke Inomura
Saturating Relationship Between Phytoplankton Growth Rate And Nutrient Concentration Explained By Macromolecular Allocation, Jongsun Kim, Gabrielle Armin, Keisuke Inomura
School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations
Phytoplankton account for about a half of photosynthesis in the world, making them a key player in the ecological and biogeochemical systems. One of the key traits of phytoplankton is their growth rate because it indicates their productivity and affects their competitive capability. The saturating relationship between phytoplankton growth rate and environmental nutrient concentration has been widely observed yet the mechanisms behind the relationship remain elusive. Here we use a mechanistic model and metadata of phytoplankton to show that the saturating relationship between growth rate and nitrate concentration can be interpreted by intracellular macromolecular allocation. At low nitrate levels, the …
Coral-Excavating Sponge Cliona Delitrix: Current Trends Of Space Occupation On High Latitude Coral Reefs, Ari Halperin, Andia Chaves-Fonnegra, David S. Gilliam
Coral-Excavating Sponge Cliona Delitrix: Current Trends Of Space Occupation On High Latitude Coral Reefs, Ari Halperin, Andia Chaves-Fonnegra, David S. Gilliam
Marine & Environmental Sciences Faculty Articles
The recent increase in abundance of coral-excavating sponges is a threat to the health of coral reefs. However, the distribution and growth of these sponges are poorly documented on high latitude reefs where corals live in marginal environmental conditions. In this study, we characterize the current trends of space occupation of Cliona delitrix on high latitude reefs (26°N) in southeast Florida. C. delitrix densities were significantly higher on the deepest habitat of this reef tract (the outer reef) in response to a higher availability of coral substratum. Sponge growth rates increased with depth, and in relation to presence of tunicates …
Low Florida Coral Calcification Rates In The Plio-Pleistocene, Thomas C. Brachert, Markus Reuter, Stefan Kruger, James S. Klaus, Kevin P. Helmle, Janice M. Lough
Low Florida Coral Calcification Rates In The Plio-Pleistocene, Thomas C. Brachert, Markus Reuter, Stefan Kruger, James S. Klaus, Kevin P. Helmle, Janice M. Lough
Marine & Environmental Sciences Faculty Articles
In geological outcrops and drill cores from reef frameworks, the skeletons of scleractinian corals are usually leached and more or less completely transformed into sparry calcite because the highly porous skeletons formed of metastable aragonite (CaCO3) undergo rapid diagenetic alteration. Upon alteration, ghost structures of the distinct annual growth bands often allow for reconstructions of annual extension ( = growth) rates, but information on skeletal density needed for reconstructions of calcification rates is invariably lost. This report presents the bulk density, extension rates and calcification rates of fossil reef corals which underwent minor diagenetic alteration only. The corals derive from …
Iron Supply And Demand In Antarctic Shelf Ecosystem, D. J. Mcgillicuddy Jr., Peter N. Sedwick, Michael S. Dinniman, K. R. Arrigo, T. S. Bibby, B. J. W. Greenan, Eileen E. Hofmann, John M. Klinck, W. O. Smith Jr., S. L. Mack, C. M. Marsay, B. M. Sohst, G. L. Van Dijken
Iron Supply And Demand In Antarctic Shelf Ecosystem, D. J. Mcgillicuddy Jr., Peter N. Sedwick, Michael S. Dinniman, K. R. Arrigo, T. S. Bibby, B. J. W. Greenan, Eileen E. Hofmann, John M. Klinck, W. O. Smith Jr., S. L. Mack, C. M. Marsay, B. M. Sohst, G. L. Van Dijken
OES Faculty Publications
The Ross Sea sustains a rich ecosystem and is the most productive sector of the Southern Ocean. Most of this production occurs within a polynya during the November-February period, when the availability of dissolved iron (dFe) is thought to exert the major control on phytoplankton growth. Here we combine new data on the distribution of dFe, high-resolution model simulations of ice melt and regional circulation, and satellite-based estimates of primary production to quantify iron supply and demand over the Ross Sea continental shelf. Our analysis suggests that the largest sources of dFe to the euphotic zone are wintertime mixing and …
Is Seagrass An Important Nursery Habitat For The Caribbean Spiny Lobster, Panulirus Argus, In Florida?, Donald C. Behringer, Mark J. Butler Iv, William Herrnkind, John H. Hunt, Charles A. Acosta, William C. Sharp
Is Seagrass An Important Nursery Habitat For The Caribbean Spiny Lobster, Panulirus Argus, In Florida?, Donald C. Behringer, Mark J. Butler Iv, William Herrnkind, John H. Hunt, Charles A. Acosta, William C. Sharp
Biological Sciences Faculty Publications
Caribbean spiny lobster (Panulirus argus) settle preferentially in macroalgal-covered hard-bottom habitat, but seagrass is more prevalent in Florida (United States) and the Caribbean, so even low settlement of lobsters within seagrass could contribute substantially to recruitment if post-settlement survival and growth were high. We tested the role of seagrass and hard-bottom habitats for P. argus recruitment in three ways. We first explored possible density-dependent regulation of early benthic juvenile lobster survival within cages deployed in seagrass and hard-bottom habitats. Second, we compared settlement and survival of P. argus in both habitats, by comparing the recovery of microwire-tagged early …
Influence Of Irradiance And Iron On The Growth Of Colonial Phaeocystic Antarctica: Implications For Seasonal Bloom Dynamics In The Ross Sea, Antarctica, Nathan S. Garcia, Peter N. Sedwick, Giacomo R. Ditullio
Influence Of Irradiance And Iron On The Growth Of Colonial Phaeocystic Antarctica: Implications For Seasonal Bloom Dynamics In The Ross Sea, Antarctica, Nathan S. Garcia, Peter N. Sedwick, Giacomo R. Ditullio
OES Faculty Publications
Laboratory culture experiments were used to investigate the growth rate of colonial Phaeocystis anarctica as a function of irradiance and dissolved iron concentration. The experiments were conducted with a P. antarctica strain isolated from the southern Ross Sea, Antarctica, and made use of natural, low-iron (P. antarctica attained an average maximum cell-specific growth rate of 0.37 d-1at an irradiance of 68 μE m-2s-1, above which growth rates decreased to 0.27 d-1 at an irradiance of 314 μE m-2s-1. The dependence of growth rate on ambient dissolved iron concentration was …
Intraspecific Variation In The Selenium Requirement Of Different Geographic Strains Of The Toxic Dinoflagellate Gymnodinium Catenatum, Martina A. Doblin, Susan I. Blackburn, Gustaaf M. Hallegraeff
Intraspecific Variation In The Selenium Requirement Of Different Geographic Strains Of The Toxic Dinoflagellate Gymnodinium Catenatum, Martina A. Doblin, Susan I. Blackburn, Gustaaf M. Hallegraeff
OES Faculty Publications
The requirement for selenium (IV) was assessed in five strains of the toxic dinoflagellate Gymnodinium catenatum Graham, representing three populations from Tasmania (Australia), as well as one each from Japan and Spain. Strains were grown in nutrient-enriched sea water medium with 10-9 M selenium added as selenite (H2SeO3), or with no added selenium, and monitored for growth and cell yield. Strains exhibited different selenium (Se) requirements, as evidenced by (i) a decrease in exponential growth rate (10-20%) and cell yield (up to 80%) (Japanese strain); (ii) a decrease in cell yield only (Tasmania Derwent Estuary …
Comparative Study Of Selenium Requirements Of Three Phytoplankton Species: Gymnodinium Catenatum, Alexandrium Minutum (Dinophyta) And Chaetoceros Cf. Tenuissimus (Bacillariophyta, Martina A. Doblin, Susan I. Blackburn, Gustaaf M. Hallegraeff
Comparative Study Of Selenium Requirements Of Three Phytoplankton Species: Gymnodinium Catenatum, Alexandrium Minutum (Dinophyta) And Chaetoceros Cf. Tenuissimus (Bacillariophyta, Martina A. Doblin, Susan I. Blackburn, Gustaaf M. Hallegraeff
OES Faculty Publications
This study investigated the selenium (Se) requirements of three phytoplankton species which commonly bloom in southern Australian estuaries. The present study showed that the toxic dinoflagellate Gymnodinium catenatum Graham had an obligate requirement for Se (IV) in culture. After two transfers (~ 4 weeks ≈ 7 generations) in Se-deficient seawater medium, this phytoplankton species exhibited a decline in growth rate (25%) and biomass yield (90%), while complete cessation of cell division occurred under prolonged (8 weeks ≈ 12 generations) Se starvation. Addition of 10-9-10-7 M H2SeO3 to nutrient-enriched seawater medium resulted in increased G.catenatum …
Resource Allocation And Sucrose Mobilization In Light Limited Eelgrass Zostera Marina, Teresa Alcoverro, Richard C. Zimmerman, Donald G. Kohrs, Randall S. Alberte
Resource Allocation And Sucrose Mobilization In Light Limited Eelgrass Zostera Marina, Teresa Alcoverro, Richard C. Zimmerman, Donald G. Kohrs, Randall S. Alberte
OES Faculty Publications
This study evaluated the ability of Zostera marina L. (eelgrass) to balance the daily photosynthetic deficit by mobilization of carbon reserves stored in below-ground tissues during a period of extreme winter light limitation. A quantitative understanding of the mobilization process and its limitations is essential to the development of robust models predicting minimum light levels required to maintain healthy seagrass populations. Plants were grown in running seawater tanks under 2 light regimes. One treatment was provided with 2 h irradiance-saturated photosynthesis (Hsat) to produce severe Light Limitation, while control plants were grown under 7 h Hsat, …
Mesures Directes Et Modélisation De La Croissance Rapide D'Un Crinoïde Pédonculé Bathyal Au Large Des Bahamas (Direct Measurement And Inferred Model Of Rapid Growth In A Bathyal Stalked Crinoid From Bahamas Islands), Jérôme David, Charles G. Messing, Tomasz K. Baumiller, Nadia Améziane, Michel Roux
Mesures Directes Et Modélisation De La Croissance Rapide D'Un Crinoïde Pédonculé Bathyal Au Large Des Bahamas (Direct Measurement And Inferred Model Of Rapid Growth In A Bathyal Stalked Crinoid From Bahamas Islands), Jérôme David, Charles G. Messing, Tomasz K. Baumiller, Nadia Améziane, Michel Roux
Marine & Environmental Sciences Faculty Articles
Several specimens of the isocrinid crinoid Neocrinus decorus were collected from a depth of 420 m off Bahamas Islands with the research submersible Johnson Sea Link. To study growth rates, these specimens were tagged, deployed and then recovered 250 days later. The average growth rate of stalk length is 10.8 cm.year−1 with a maximum value at 14.3 cm.year−1. These results allow us to propose a model of growth and regeneration for stalked crinoids in which the energy allocation is modulated through time to the arms and the stalk. Following arm autotomy, in order to re-establish optimum filtration …
Effect Of Light/Dark Transition On Carbon Translocation In Eelgrass Zostera Marina Seedlings, Richard C. Zimmerman, Randall S. Alberte
Effect Of Light/Dark Transition On Carbon Translocation In Eelgrass Zostera Marina Seedlings, Richard C. Zimmerman, Randall S. Alberte
OES Faculty Publications
Carbon translocation in the marine macrophyte Zostera marina L. (eelgrass) was investigated to elucidate the impact of light/dark transitions on sucrose partitioning between roots and shoots. After exposure of leaves to C-14-bicarbonate, the level of C-14-labelled photoassimilates increased monotonically in both leaves and fully aerobic roots of plants maintained in the light. Accumulation of C-14 in roots and leaves ceased abruptly when plants were transferred to darkness that induced root anaerobiosis even though C-14 levels remained high in the dark-exposed leaves. Thus, translocation of C-14 photoassimilates from shoots to roots was inhibited when roots became anoxic. Anoxia induced by light …
Modeling Oyster Populations Ii. Adult Size And Reproductive Effort, E. E. Hofmann, J. M. Klinck, E. N. Powell, S. Boyles, M. Ellis
Modeling Oyster Populations Ii. Adult Size And Reproductive Effort, E. E. Hofmann, J. M. Klinck, E. N. Powell, S. Boyles, M. Ellis
CCPO Publications
A time-dependent model of energy flow in post-settlement oyster populations is used to examine the factors that influence adult size and reproductive effort in a particular habitat, Galveston Bay, Texas, and in habitats that extend from Laguna Madre, Texas to Chesapeake Bay. The simulated populations show that adult size and reproductive effort are determined by the allocation of net production to somatic or reproductive tissue development and the rate of food acquisition, both of which are temperature dependent. For similar food conditions, increased temperature reduces the allocation of net production to somatic tissue and increases the rate of food acquisition. …
Modeling Oyster Populations. Iv. Rates Of Mortality, Population Crashes, And Management, E. N. Powell, J. M. Klinck, E. E. Hofmann, S. M. Ray
Modeling Oyster Populations. Iv. Rates Of Mortality, Population Crashes, And Management, E. N. Powell, J. M. Klinck, E. E. Hofmann, S. M. Ray
CCPO Publications
A time-dependent energy-flow model was used to examine how mortality affects oyster populations over the latitudinal gradient from Galveston Bay, Texas, to Chesapeake Bay, Virginia. Simulations using different mortality rates showed that mortality is required for market-site oysters to be a component of the population's size-frequency distribution; otherwise a population of stunted individuals results. As mortality extends into the juvenile sizes, the population's size frequency shifts toward the larger sizes. In many cases adults increase despite a decrease in overall population abundance. Simulations, in which the timing of mortality varied, showed that oyster populations are more susceptible to population declines …
A Comparison Of A Validated Otolith Method To Age Weakfish, Cynoscion Regalis, With The Traditional Scale Method, Susan K. Lowerre-Barbieri, Mark E. Chittenden Jr., Cynthia M. Jones
A Comparison Of A Validated Otolith Method To Age Weakfish, Cynoscion Regalis, With The Traditional Scale Method, Susan K. Lowerre-Barbieri, Mark E. Chittenden Jr., Cynthia M. Jones
OES Faculty Publications
Otoliths, scales, dorsal spines, and pectoral-fin rays were compared to ascertain the best hardpart for determining the age of weakfish, Cynoscion regalis. Each showed concentric marks, which could be interpreted as annuli. Sectioned otoliths, however, consistently showed the clearest marks, had 100% agreement between and within readers, and were validated by the marginal increment method for ages 1-5. This validated method of ageing weakfish was then compared with the traditionally used scale method. The scale method was less precise, as demonstrated by lower percent agreement, and generally assigned younger ages for fish older than age 6 (as determined by …
Skeletal Structural Basis Of Density Banding In The Reef Coral Montastrea Annularis, Richard E. Dodge, Alina Szmant-Froelich, R. Garcia, Peter K. Swart, A. Forester, J. J. Leder
Skeletal Structural Basis Of Density Banding In The Reef Coral Montastrea Annularis, Richard E. Dodge, Alina Szmant-Froelich, R. Garcia, Peter K. Swart, A. Forester, J. J. Leder
Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures
Density banding in coral skeletons can provide for reconstruction of the coral's growth en- vironment over long periods. The physical differ- ences between low and high density portions of a skeletal band are not well understood. The skeletal architecture of M. annularis from Southeast Flor- ida, the Florida Keys, St. Croix, the Bahamas, and Mexico was compared in X-ray revealed high den- sity (HD), low density (LD), and stress HD bands. Density changes arose from differences in the size, but not spacing, of exothecal structural elements (horizontal dissepiments and vertical costae). En- dothecal architecture size (e.g., columella, dissepi- ments, septa) …