COS Faculty Works
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Item Trichophycin A, a cytotoxic linear polyketide isolated from a Trichodesmium thiebautii bloom(MDPI, 1/6/2017) Bertin, Matthew J.; Wahome, Paul G.; Zimba, Paul V.; He, Haiyin; Moeller, Peter D. R.In an effort to isolate and characterize bioactive secondary metabolites from Trichodesmium thiebautii blooms, collected cyanobacteria biomass was subjected to bioassay-guided extraction and fractionation using the human colon cancer cell line HCT-116, resulting in the isolation and subsequent structure characterization of a linear polyketide trichophycin A (1). The planar structure of 1 was completed using 1D and 2D NMR spectroscopy and high-resolution electrospray ionization mass spectrometry (HRESIMS). Trichophycin A was moderately toxic against the murine neuroblastoma cell line Neuro-2A (EC50: 6.5 μM) and HCT-116 cells (EC50: 11.7 μM). Trichophycin A was significantly more cytotoxic than the previously isolated polyketides trichotoxin A and trichotoxin B. These cytotoxicity observations suggest that toxicity may be related to the polyol character of these polyketide compounds.Item Development of a green fluorescent protein-based laboratory curriculum(IUMBM Journals, 2005-01) Larkin, PatrickA laboratory curriculum has been designed for an undergraduate biochemistry course that focuses on the investigation of the green fluorescent protein (GFP). The sequence of procedures extends from analysis of the DNA sequence through PCR amplification, recombinant plasmid DNA synthesis, bacterial transformation, expression, isolation, and characterization of the protein by SDS-PAGE. A survey of participants found that the majority of them were performing most of these procedures for the first time and that participants found the exercises enjoyable and considered them a significant aid to their understanding of biochemistry, cell biology, and molecular genetics.Item Optimization of 12 chiral analytes with 8 polymeric surfactants(Oxford Academic, 2008-10-01) Billiot, Eugene; Billiot, Fereshteh; Warner, IsiahThis manuscript discusses the results of studies that were performed to determine optimum capillary electrophoresis (CE) conditions for the enantiomeric resolution of twelve chiral analytes with eight amino acid based polymeric surfactants. The parameters that were optimized include pH, buffer type, and concentration of surfactant. The results indicated that the optimum conditions for enantiomeric separations with the amino acid based polymeric surfactants examined in this study using CE were analyte dependent, not surfactant dependent. In other words, the optimum conditions for a particular analyte were the same for all the amino acid based polymeric surfactants examined in this study. The results of these studies indicate that when using a large group of related amino acid based polymeric surfactants only a few surfactants need to be optimized for each analyte under study. These studies were limited to anionic surfactants that contain the amino acids glycine, L-alanine, L-valine, and L-leucine only. No inference can be necessarily drawn about surfactants containing other types of amino acids such as threonine and serine, which contain extra heteroatoms, or phenylalanine that has an aromatic moiety.Item Habitat use patterns of newly settled southern flounder, paralichthys lethostigma, in Aransas–Copano Bay, Texas(Springer, 2008-10-31) Nañez-James, Suraida E.; Stunz, Gregory; Holt, Scott A.Southern flounder Paralichthys lethostigma populations have been declining in Texas during the past 25 years. Despite their economic importance, little is known about their juvenile habitat requirements. We examined habitat use patterns of newly settled southern flounder in three zones at varying distances from the Aransas Pass inlet in Aransas–Copano Bay by measuring densities using a beam trawl in replicate estuarine habitat types in each zone. Highest abundance occurred near the inlet in vegetated sandy areas and was lowest in nonvegetated muddy bottom in regions furthest from the inlet. We also examined a 25-year fisheries data set from Texas Parks and Wildlife Department to evaluate long-term spatiotemporal recruitment patterns in Aransas–Copano Bay. These data showed generally low recruitment during the past 25 years with highest abundance near the inlets. Our results support the importance of vegetated habitat types, especially those near tidal passes, and suggest a long-term decline in recruitment densities of southern flounder.Item Role of science-based and adaptive management in allocating environmental flows to the Nueces estuary, Texas, use(WIT Press, 2009-06) Montagna, Paul A.; Hill, Erin M.; Moulton, B.The Nueces River System has been subject to adaptive management since construction of the Choke Canyon Reservoir in 1982. A special condition required the City of Corpus Christi to provide not less than 185 million cubic meters (151,000 ac-ft) of water per year to the Nueces Estuary through a combination of spills, releases, and return flows to maintain ecological health and productivity of living marine resources. However, no releases were made and salinities in Nueces Bay increased to hypersaline conditions during the drought period of 1988–1990 and the estuary was inverted where fresher water entered the delta on high tides. In contrast, the bay historically supported populations of shrimp and oysters generally requiring salinities in the range of 10–20 ppt. Beginning in May 1990, the Texas Water Commission issued a series of Orders requiring the City to meet the special conditions contained in their water right permit and provide for freshwater inflows to the estuary. Since 1990, a series of restoration activities, monitoring and experimental studies, and Order amendments has resulted in a stakeholder driven process that increased environmental health while providing a sustainable water supply to the region. However, with climate change and continued development, more changes are likely to occur in the future. The lesson learned is that the goal of achieving consensus can occur with a blend and balance of science and a stakeholder decision process. Keywords: freshwater inflow, wetlands, marsh, shellfish, dams, water resources.Item The effect of boat propeller scarring intensity on genetic variation in a subtropical seagrass species(De Gruyter, 2009-12-15) Larkin, Patrick; Heideman, Krista L.; Burfeind, Dana; Stunz, Gregory; Larkin, Patrick; Heideman, Krista L.; Burfeind, Dana; Stunz, GregoryWe report here the effect of one form of disturbance, boat propeller scarring, on genetic variation in the subtropical seagrass Halodule wrightii. We developed an amplified fragment length polymorphism assay to measure genetic var-aition in plots representing four levels of scarring intensity: reference (0% scarring), low (1–5%), moderate (5–15%) and severe (>15%). Although we found severely scarred plots to have the lowest, and moderately scarred plots to have the highest, mean genetic diversity estimates (He,P), differences among scarring levels were found to be non-significant(as0.05). Analysis of molecular variance also showed no significant effect of scarring intensity. While propeller scar-ring can cause significant habitat loss, scarring intensities of up to 20% may not yet have seriously affected those factors (population size, flowering density, recruitment, gene flow)that strongly influence population genetic variation. The relatively recent occurrence of this type of disturbance, how-ever, could mean that any long-term effects have yet to detectedItem Seagrass response to wastewater inputs: Implementation of a seagrass monitoring program in two Texas estuaries(2011-02-25) Cammarata, KirkThe study protocol followed a recent proposal by Dunton and Pulich to the Seagrass Monitoring Work Group (Landscape Monitoring and Biological Indicators for Seagrass Conservation in Texas Coastal Waters, draft, Dunton et al. 2007) and included three components: 1) landscape monitoring using high resolution color aerial photography, 2) seagrass condition and water quality indicators, and 3) seagrass epiphyte fluorescence analysis. Findings from the third objective are presented here.Item Existence of a unique solution to a quasilinear elliptic equation(Elsevier, 2011-03-29) Denny, DianeThe purpose of this paper is to prove the existence of a unique classical solution u(x) to the quasilinear elliptic equation −∇ · (a(u)∇u) + v · ∇u = f , where u(x0) = u0 at x0 ∈ Ω and where n · ∇u = g on the boundary ∂Ω. We prove that if the functions a, f , v, g satisfy certain conditions, then a unique classical solution u(x) exists. Applications include stationary heat/diffusion problems with convection and with a source/sink, where the value of the solution is known at a spatial location x0 ∈ Ω, and where n · ∇u is known on the boundary.Item MERIS retrieval of water quality components in the turbid Albemarle Pamlico sound estuary, USA(MDPI, 2011-04-01) Sokoletsky, Leonid G.; Lunetta, Ross S.; Wetz, Michael S.; Paerl, Hans W.Two remote-sensing optical algorithms for the retrieval of the water quality components (WQCs) in the Albemarle-Pamlico Estuarine System (APES) were developed and validated for chlorophyll a (Chl). Both algorithms were semi-empirical because they incorporated some elements of optical processes in the atmosphere, water, and air/water interface. One incorporated a very simple atmospheric correction and modified quasi-single-scattering approximation (QSSA) for estimating the spectral Gordon’s parameter, and the second estimated WQCs directly from the top of atmosphere satellite radiance without atmospheric corrections. A modified version of the Global Meteorological Database for Solar Energy and Applied Meteorology (METEONORM) was used to estimate directional atmospheric transmittances. The study incorporated in situ Chl data from the Ferry-Based Monitoring (FerryMon) program collected in the Neuse River Estuary (n = 633) and Pamlico Sound (n = 362), along with Medium Resolution Imaging Spectrometer (MERIS) satellite imagery collected (2006–2009) across the APES; providing quasi-coinciding samples for Chl algorithm development and validation. Results indicated a coefficient of determination (R2) of 0.70 and mean-normalized root-mean-squares errors (NRMSE) of 52% in the Neuse River Estuary and R2 = 0.44 (NRMSE = 75 %) in the Pamlico Sound—without atmospheric corrections. The simple atmospheric correction tested provided on performance improvements. Algorithm performance demonstrated the potential for supporting long-term operational WQCs satellite monitoring in the APES.Item Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean(AGU, 2011-09-23) Santorelli, A.; Pinker, R. T.; Bentamy, Anas; Katsaros, K. B.; Drennan, W. M.; Mestas Nuñez, Marcos; Carton, J. A.[1] Uncertainties in turbulent ocean-atmosphere heat flux estimates, both among the estimates and between them and ground truth, suggest that further comparisons are needed. We analyze estimates from the French Research Institute for Exploitation of the Sea (IFREMER) and the Woods Hole Oceanographic Institution's Objectively Analyzed air-sea Fluxes (WHOI OAFlux). The IFREMER products are based on satellite observations and the WHOI OAFlux ones on data from satellites, buoys, and ships assimilated into numerical analyses. We focus on the Atlantic sector (70°W–30°E, 45°S–45°N) during 1996–2005, where the variables that enter the bulk formulae for computing fluxes (wind speed, sea surface and air temperature, and specific humidity) can be evaluated against buoys in the Prediction and Research Moored Array in the Atlantic (PIRATA). Since WHOI assimilates PIRATA observations, we have added two independent buoy data sets: FETCH and ROMEO. To examine how each variable contributes to the difference between estimated and buoy fluxes, the method of Bourras (2006) is applied. His so-called Q terms showed that specific air humidity and air temperature contributed the most to the biases of IFREMER latent and sensible heat fluxes, respectively, at both independent buoys. For WHOI OAFlux products, deviations from FETCH values were mainly due to wind speed and sea surface temperature differences, while in comparison with ROMEO fluxes, WHOI OAFlux biases were primarily due to specific humidity and sea surface temperature estimates. Modified estimates of turbulent fluxes with the IFREMER approach using the 10 m specific humidity and air temperature products of Jackson et al. (2009) show significant improvement in three test cases at PIRATA buoys.Item Development of gene expression markers of acute heat-light stress in reef-building corals of the genus porites(PLOS ONE, 2011-10-26) Kenkel, Carly; Aglyamova, Galina; Alamaru, Ada; Bhagooli, Ranjeet; Capper, Roxana; Cunning, Ross; deVillers, Amanda; Haslun, Joshua; Hédouin, Laetitia; Keshavmurthy, Shashank; Kuehl, Kristin A.; Mahmoud, Huda; McGinty, Elizabeth S.; Montoya Maya, Phanor Hernando; Palmer, Caroline V.; Pantile, Raffaella; Sánchez, Juan A.; Schils, Tom; Silverstein, Rachel N.; Squiers, Logan B.; Tang, Pei-Ciao; Goulet, Tamar; Matz, Mikhail; Kenkel, Carly; Aglyamova, Galina; Alamaru, Ada; Bhagooli, Ranjeet; Capper, Roxana; Cunning, Ross; deVillers, Amanda; Haslun, Joshua; Hédouin, Laetitia; Keshavmurthy, Shashank; Kuehl, Kristin A.; Mahmoud, Huda; McGinty, Elizabeth S.; Montoya Maya, Phanor Hernando; Palmer, Caroline V.; Pantile, Raffaella; Sánchez, Juan A.; Schils, Tom; Silverstein, Rachel N.; Squiers, Logan B.; Tang, Pei-Ciao; Goulet, Tamar; Matz, MikhailCoral reefs are declining worldwide due to increased incidence of climate-induced coral bleaching, which will have widespread biodiversity and economic impacts. A simple method to measure the sub-bleaching level of heat-light stress experienced by corals would greatly inform reef management practices by making it possible to assess the distribution of bleaching risks among individual reef sites. Gene expression analysis based on quantitative PCR (qPCR) can be used as a diagnostic tool to determine coral condition in situ. We evaluated the expression of 13 candidate genes during heat-light stress in a common Caribbean coral Porites astreoides, and observed strong and consistent changes in gene expression in two independent experiments. Furthermore, we found that the apparent return to baseline expression levels during a recovery phase was rapid, despite visible signs of colony bleaching. We show that the response to acute heat-light stress in P. astreoides can be monitored by measuring the difference in expression of only two genes: Hsp16 and actin. We demonstrate that this assay discriminates between corals sampled from two field sites experiencing different temperatures. We also show that the assay is applicable to an Indo-Pacific congener, P. lobata, and therefore could potentially be used to diagnose acute heat-light stress on coral reefs worldwide.Item Static inflation and deflation pressure–volume curves from excised lungs of marine mammals(The Company of Biologists, 2011-11-15) Fahlman, Andreas; Loring, Stephen; Ferrigno, Massimo; Moore, Colby; Early, Greg; Niemeyer, Misty; Lentell, Betty; Wenzel, Frederic; Joy, Ruth; Moore, Michael J.Excised lungs from eight marine mammal species [harp seal (Pagophilus groenlandicus), harbor seal (Phoca vitulina), gray seal (Halichoerus grypush), Atlantic white-sided dolphin (Lagenorhynchus acutus), common dolphin (Delphinus delphis), Risso's dolphin (Grampus griseus), long-finned pilot whale (Globicephala melas) and harbor porpoise (Phocoena phocoena)] were used to determine the minimum air volume of the relaxed lung (MAV, N=15), the elastic properties (pressure–volume curves, N=24) of the respiratory system and the total lung capacity (TLC). Our data indicate that mass-specific TLC (sTLC, l kg–1) does not differ between species or groups (odontocete vs phocid) and agree with that estimated (TLCest) from body mass (Mb) by applying the equation: TLCest=0.135 Mb0.92. Measured MAV was on average 7% of TLC, with a range from 0 to 16%. The pressure–volume curves were similar among species on inflation but diverged during deflation in phocids in comparison with odontocetes. These differences provide a structural basis for observed species differences in the depth at which lungs collapse and gas exchange ceases.Item Estimated tissue and blood N2 levels and risk of decompression sickness in deep-, intermediate-, and shallow-diving toothed whales during exposure to naval sonar(Frontiers, 2012-05-10) Kvadsheim, Petter H; Miller, P. J. O.; Tyack, P. L.; Sivle, Lise Doksæter; Lam, F. P. A.; Fahlman, AndreasNaval sonar has been accused of causing whale stranding by a mechanism which increases formation of tissue N2 gas bubbles. Increased tissue and blood N2 levels, and thereby increased risk of decompression sickness (DCS), is thought to result from changes in behavior or physiological responses during diving. Previous theoretical studies have used hypothetical sonar-induced changes in both behavior and physiology to model blood and tissue N2 tension (PN2), but this is the first attempt to estimate the changes during actual behavioral responses to sonar. We used an existing mathematical model to estimate blood and tissue N2 tension (PN2) from dive data recorded from sperm, killer, long-finned pilot, Blainville’s beaked, and Cuvier’s beaked whales before and during exposure to Low- (1–2 kHz) and Mid- (2–7 kHz) frequency active sonar. Our objectives were: (1) to determine if differences in dive behavior affects risk of bubble formation, and if (2) behavioral- or (3) physiological responses to sonar are plausible risk factors. Our results suggest that all species have natural high N2 levels, with deep diving generally resulting in higher end-dive PN2 as compared with shallow diving. Sonar exposure caused some changes in dive behavior in both killer whales, pilot whales and beaked whales, but this did not lead to any increased risk of DCS. However, in three of eight exposure session with sperm whales, the animal changed to shallower diving, and in all these cases this seem to result in an increased risk of DCS, although risk was still within the normal risk range of this species. When a hypothetical removal of the normal dive response (bradycardia and peripheral vasoconstriction), was added to the behavioral response during model simulations, this led to an increased variance in the estimated end-dive N2 levels, but no consistent change of risk. In conclusion, we cannot rule out the possibility that a combination of behavioral and physiological responses to sonar have the potential to alter the blood and tissue end-dive N2 tension to levels which could cause DCS and formation of in vivo bubbles, but the actually observed behavioral responses of cetaceans to sonar in our study, do not imply any significantly increased risk of DCS.Item Changes in dive behavior during naval sonar exposure in killer whales, long-finned pilot whales, and sperm whales(Frontier, 2012-10-11) Sivle, Lise Doksæter; Kvadsheim, Petter H; Fahlman, Andreas; Lam, F. P. A.; Tyack, P. L.; Miller, P. J. O.Anthropogenic underwater sound in the environment might potentially affect the behavior of marine mammals enough to have an impact on their reproduction and survival. Diving behavior of four killer whales (Orcinus orca), seven long-finned pilot whales (Globicephala melas), and four sperm whales (Physeter macrocephalus) was studied during controlled exposures to naval sonar [low frequency active sonar (LFAS): 1–2 kHz and mid frequency active sonar (MFAS): 6–7 kHz] during three field seasons (2006–2009). Diving behavior was monitored before, during and after sonar exposure using an archival tag placed on the animal with suction cups. The tag recorded the animal's vertical movement, and additional data on horizontal movement and vocalizations were used to determine behavioral modes. Killer whales that were conducting deep dives at sonar onset changed abruptly to shallow diving (ShD) during LFAS, while killer whales conducting deep dives at the onset of MFAS did not alter dive mode. When in ShD mode at sonar onset, killer whales did not change their diving behavior. Pilot and sperm whales performed normal deep dives (NDD) during MFAS exposure. During LFAS exposures, long-finned pilot whales mostly performed fewer deep dives and some sperm whales performed shallower and shorter dives. Acoustic recording data presented previously indicates that deep diving (DD) is associated with feeding. Therefore, the observed changes in dive behavior of the three species could potentially reduce the foraging efficiency of the affected animals.Item The ontogenetic scaling of bite force and head size in loggerhead sea turtles (Caretta caretta): Implications for durophagy in neritic, benthic habitats(The company of biologist, 2012-12-01) Marshall, Christopher D.; Guzman, Alejandra; Narazaki, Tomoko; Sato, Katsufumi; Kane, Emily; Sterba-Boatwright, BlairOntogenetic studies of vertebrate feeding performance can help address questions relevant to foraging ecology. Feeding morphology and performance can either limit access to food resources or open up new trophic niches in both aquatic and terrestrial systems. Loggerhead sea turtles are long-lived vertebrates with complex life histories that are marked by an ontogenetic shift from an oceanic habitat to a coastal neritic habitat, and a transition from soft oceanic prey to hard, benthic prey. Although considered durophagous and strong biters, bite performance has not been measured in loggerheads, nor has the ontogeny of bite performance been characterized. In the present study, we collected measurements of bite force in loggerhead turtles from hatchlings to adults. When subadults reach the body size at which the ontogenetic shift occurs, their crushing capability is great enough for them to consume numerous species of hard benthic prey of small sizes. As loggerheads mature and bite performance increases, larger and harder benthic prey become accessible. Loggerhead bite performance eventually surpasses the crushing capability of other durophagous carnivores, thereby potentially reducing competition for hard benthic prey. The increasing bite performance and accompanying changes in morphology of the head and jaws are likely an effective mechanism for resource partitioning and decreasing trophic competition. Simultaneous measurements of body and head size and the use of non-linear reduced major axis regression show that bite force increases with significant positive allometry relative to body size (straight carapace length, straight carapace width and mass) and head size (head width, height and length). Simple correlation showed that all recorded morphometrics were good predictors of measured bite performance, but an AICc-based weighted regression showed that body size (straight carapace width followed by straight carapace length and mass, respectively) were more likely predictors of bite force than head size morphometrics (head width and head length).Item The physiological consequences of breath-hold diving in marine mammals: the Scholander legacy(Frontiers in Physiology, 2012-12-19) Fahlman, AndreasItem The physiological consequences of breath-hold diving in marine mammals: The Scholander legacy(2012-12-19) Fahlman, AndreasMost of the physiological traits used by marine mammals to perform long and deep breath-hold dives were described in Scholander's seminal paper in 1940. Since then, several studies have provided an improved understanding of the mechanistic basis of the mammalian diving response (Scholander, 1940, 1963; Mottishaw et al., 1999; Fahlman et al., 2011), the aerobic dive limit (ADL) (Kooyman et al., 1980; Butler and Jones, 1997; Davis and Kanatous, 1999; Horning, 2012), and management of respiratory gases (Boutilier et al., 2001; Fahlman et al., 2008a; Hooker et al., 2009; Kvadsheim et al., 2012), but many questions remain. Some widely-accepted ideas actually lack experimental confirmation, and a variety of marine mammal species, potentially novel models for elucidating new diving adaptations, have not been adequately studied. The aim of this Frontiers Special Topic is to provide a synthesis of the current knowledge of the physiological responses that may explain the varied diving behavior of marine mammals. We strove to include contributions that challenge current ideas, and which propose new hypotheses, utilize new experimental approaches, and explore new model species.Item On the currents and transports connected with the Atlantic meridional overturning circulation in the subpolar North Atlantic(American Geophysical Union, 2013-01-04) Xu, X.; Hurlburt, H. E.; Schmitz Jr., W. J.; Zantopp, Rainer; Fischer, J.; Hogan, P. J.Results from an interannually forced, 0.08° eddy-resolving simulation based on the Hybrid Coordinate Ocean Model, in conjunction with a small but well-determined transport database, are used to investigate the currents and transports associated with the Atlantic meridional overturning circulation (AMOC) in the subpolar North Atlantic (SPNA). The model results yield a consistent warming in the western SPNA since the early 1990s, along with mean transports similar to those observed for the trans-basin AMOC across the World Ocean Circulation Experiment hydrographic section AR19 (16.4 Sv) and boundary currents at the exit of the Labrador Sea near 53°N (39.0 Sv) and east of the Grand Banks near 43°N (15.9 Sv). Over a 34 year integration, the model-determined AMOC across the AR19 section and the western boundary current near 53°N both exhibit no systematic trend but some long-term (interannual and longer) variabilities, including a decadal transport variation of 3–4 Sv from relatively high in the 1990s to low in the 2000s. The decadal variability of the model boundary current transport near 53°N lags the observed winter time North Atlantic Oscillation index by about 2 years and leads the model AMOC across the AR19 section by about 1 year. The model results also show that the long-term variabilities are low compared to those on shorter time scales. Thus, rapid sampling of the current over long time intervals is required to filter out high-frequency variabilities in order to determine the lower frequency variabilities of interest.Item Improvement in air–sea flux estimates derived from satellite observations(Taylor & Francis Online, 2013-04-17) Bentamy, Abderrahim; Grodsky, Semyon; Katsaros, Kristina; Mestas-Nuñez, Alberto M.; Blanke, Bruno; Desbiolles, FabienA new method is developed to estimate daily turbulent air–sea fluxes over the global ocean on a 0.25° grid. The required surface wind speed (w 10) and specific air humidity (q 10) at 10 m height are both estimated from remotely sensed measurements. w 10 is obtained from the SeaWinds scatterometer on board the QuikSCAT satellite. A new empirical model relating brightness temperatures (T b) from the Special Sensor Microwave Imager (SSM/I) and q 10 is developed. It is an extension of the author's previous q 10 model. In addition to T b, the empirical model includes sea surface temperature (SST) and air–sea temperature difference data. The calibration of the new empirical q 10 model utilizes q 10 from the latest version of the National Oceanography Centre air–sea interaction gridded data set (NOCS2.0). Compared with mooring data, the new satellite q 10 exhibits better statistical results than previous estimates. For instance, the bias, the root mean square (RMS), and the correlation coefficient values estimated from comparisons between satellite and moorings in the northeast Atlantic and the Mediterranean Sea are –0.04 g kg−1, 0.87 g kg−1, and 0.95, respectively. The new satellite q 10 is used in combination with the newly reprocessed QuikSCAT V3, the latest version of SST analyses provided by the National Climatic Data Center (NCDC), and 10 m air temperature estimated from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalyses (ERA-Interim), to determine three daily gridded turbulent quantities at 0.25° spatial resolution: surface wind stress, latent heat flux (LHF), and sensible heat flux (SHF). Validation of the resulting fields is performed through a comprehensive comparison with daily, in situ values of LHF and SHF from buoys. In the northeast Atlantic basin, the satellite-derived daily LHF has bias, RMS, and correlation of 5 W m−2, 27 W m−2, and 0.89, respectively. For SHF, the statistical parameters are –2 W m−2, 10 W m−2, and 0.94, respectively. At global scale, the new satellite LHF and SHF are compared to NOCS2.0 daily estimates. Both daily fluxes exhibit similar spatial and seasonal variability. The main departures are found at latitudes south of 40° S, where satellite latent and sensible heat fluxes are generally larger.Item Activity as a proxy to estimate metabolic rate and to partition the metabolic cost of diving vs. breathing in pre- and post-fasted Steller sea lions(Inter-Research Science Publisher, 2013-04-30) Fahlman, Andreas; Svärd, C.; Rosen, D. A. S.; Wilson, R. P.; Trites, AndrewThree Steller sea lions Eumetopias jubatus, trained to dive voluntarily to depths ranging from 10 to 50 m, were used to determine whether the relationship between activity and metabolic rate during a diving interval (MRDI, dive + surface interval) was affected by fasting (9 d) during the breeding season (spring through summer). We subsequently used the relationship between activity and MRDI to partition the metabolic costs between underwater breath-holding activity and surface breathing activities. We estimated activity from overall dynamic body acceleration (ODBA) measured using a 3-axis accelerometer, and measured MRDI using flow-through respirometry. The relationship between ODBA-based activity and MRDI was not affected by fasting period, suggesting that ODBA can be used to predict energy expenditure regardless of nutritional state in the spring and summer. However, the relationship between ODBA and dive metabolic rate differs from the relationship between ODBA and the surface metabolic rate before diving. Partitioning MRDI into the metabolic cost of remaining at the surface versus swimming underwater suggests that the metabolic cost of diving for Steller sea lions is approximately 29% lower than when breathing at the surface. ODBA appears to be a reasonable proxy to estimate metabolic rate in marine mammals, but more detailed behavioral data may be required to accurately apply the method in the field.