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Full-Text Articles in Life Sciences

The Use Of Extractable Lipofuscin For Age Determination Of Crustaceans: Reply To Sheehy (2008), H. Rodger Harvey, David H. Secor, Se-Jong Ju Jan 2008

The Use Of Extractable Lipofuscin For Age Determination Of Crustaceans: Reply To Sheehy (2008), H. Rodger Harvey, David H. Secor, Se-Jong Ju

OES Faculty Publications

The heterogeneous mixture of metabolic by-products termed lipofuscin (LF) or age pigments has long been known to accumulate in post mitotic cells with increasing age. In crustaceans several approaches have been developed over the years to track LF accumulation and provide a proxy for chronological age. Histological approaches have been traditionally used for LF determination of crustaceans (e.g. Sheehy et al. 1994, Mar Biol 121:237-245), but over the last decade extraction approaches for neural tissues have been introduced (Ju et al. 1999, Mar Ecol Prog Ser 185:171-179) and tested (Ju et al. 2001, Mar Ecol Prog Ser 224:197-205; 2003, Fish …


Food Limitation In Larval Fish: Ontogenetic Variation In Feeding Scope And Its Potential Effect On Survival, Alexander B. Bochdansky, Peter Grønkjær, Pierre Pepin, William C. Leggett Jan 2008

Food Limitation In Larval Fish: Ontogenetic Variation In Feeding Scope And Its Potential Effect On Survival, Alexander B. Bochdansky, Peter Grønkjær, Pierre Pepin, William C. Leggett

OES Faculty Publications

We used the radiated shanny Ulvaria subbifurcataas a model species to explore the relative gut fullness from hatch to metamorphosis of wild larvae, and compared these values with those of laboratory-reared larvae fed at maximum rates. Ingestion rates of most wild larvae were above starvation levels but below the maximum feeding levels of laboratory-reared larvae. Twenty-six percent of freshly-hatched wild larvae and 11% of large, pre-settlement wild larvae had insufficient food in their stomach to satisfy metabolic requirements. These results, taken on their own, are consistent with the much hypothesized increased foraging performance and survival of larger larvae relative …


Co2 Sensitivity Of Southern Ocean Phytoplankton, Philippe D. Tortell, Christopher D. Payne, Yingyu Li, Scarlett Trimborn, Bjorn Rost, Walker O. Smith, Christina Riesselman, Robert B. Dunbar, Peter Sedwick, Giacomo R. Ditullio Jan 2008

Co2 Sensitivity Of Southern Ocean Phytoplankton, Philippe D. Tortell, Christopher D. Payne, Yingyu Li, Scarlett Trimborn, Bjorn Rost, Walker O. Smith, Christina Riesselman, Robert B. Dunbar, Peter Sedwick, Giacomo R. Ditullio

OES Faculty Publications

The Southern Ocean exerts a strong impact on marine biogeochemical cycles and global air-sea CO2 fluxes. Over the coming century, large increases in surface ocean CO2 levels, combined with increased upper water column temps. and stratification, are expected to diminish Southern Ocean CO2 uptake. These effects could be significantly modulated by concomitant CO2-dependent changes in the region's biol. carbon pump. Here we show that CO2 concentrations affect the physiology, growth and species composition. of phytoplankton assemblages in the Ross Sea, Antarctica. Field results from in situ sampling and ship-board incubation experiments demonstrate that inorganic …


Ship Ballast Tanks: How Microbes Travel The World, Fred C. Dobbs Jan 2008

Ship Ballast Tanks: How Microbes Travel The World, Fred C. Dobbs

OES Faculty Publications

As the international shipping fleet travels the oceans, it carries with it hidden cargoes of microbes. Fred C. Dobbs explores the hazards posed and what can be done to counteract them.


Interactions Between Changing Pco2, N2 Fixation, And Fe Limitation In The Marine Unicellular Cyanobacterium Crocosphaera, Fei-Xue Fu, Margaret R. Mulholland, Nathan S. Garcia, Aaron Beck, Mark E. Warner, Sergio A. Sañudo, David A. Hutchins Jan 2008

Interactions Between Changing Pco2, N2 Fixation, And Fe Limitation In The Marine Unicellular Cyanobacterium Crocosphaera, Fei-Xue Fu, Margaret R. Mulholland, Nathan S. Garcia, Aaron Beck, Mark E. Warner, Sergio A. Sañudo, David A. Hutchins

OES Faculty Publications

We examined the physiological responses of steady-state iron (Fe)-replete and Fe-limited cultures of the biogeochemically critical marine unicellular diazotrophic cyanobacterium Crocosphaera at glacial (19 Pa; 190 ppm), current (39 Pa; 380 ppm), and projected year 2100 (76 Pa; 750 ppm) CO2 levels. Rates of N2 and CO2 fixation and growth increased in step with increasing partial pressure of CO2 (pCO2), but only under Fe- replete conditions. N2) and carbon fixation rates at 75 Pa CO2 were 1.4-1.8-fold and 1.2-2.0-fold higher, respectively, relative to those at present day and glacial pCO2 …


Rates Of Carbonate Dissolution In Permeable Sediments Estimated From Porewater Profiles: The Role Of Sea Grasses, David J. Burdige, Richard C. Zimmerman, Xinping Hu Jan 2008

Rates Of Carbonate Dissolution In Permeable Sediments Estimated From Porewater Profiles: The Role Of Sea Grasses, David J. Burdige, Richard C. Zimmerman, Xinping Hu

OES Faculty Publications

In this study we estimate sediment carbonate dissolution rates for sandy sea grass sediments on the Bahamas Bank using an inverse pore-water advection/diffusion/reaction model constrained by field observations. This model accounts for sea grass O2 input to these sediments, and also parameterizes pore-water advection through these permeable sediments as a nonlocal exchange process. The resulting rates of carbonate dissolution are positively correlated with sea grass density, and are comparable with previous rate estimates for Florida Bay sediments. In contrast, the advective uptake of O2 by these sediments decreased with increasing sea grass density. This suggests that the competing …