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Your search keyword '"McLaskey, Anna K."' showing total 22 results
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22 results on '"McLaskey, Anna K."'

10. Physiological observations of Euphausia pacifica after a ten-day acclimation to dissolved oxygen (DO) and pH conditions in two separate laboratory experiments.

Author

McLaskey, Anna K., Keister, Julie E., McLaskey, Anna K., and Keister, Julie E.

Abstract

Dataset: Krill physiology - Experimental conditions, Physiological observations of Euphausia pacifica after a ten-day acclimation to dissolved oxygen (DO) and pH conditions in two separate laboratory experiments. Krill was sampled in the Puget Sound, WA, USA aboard R/V Clifford Barnes during cruises CB1073 and CB1078 in 2017. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/840572, NSF Division of Ocean Sciences (NSF OCE) OCE-1154648

Published
2021

11. Seawater conditions monitored and recorded during two separate laboratory experiments in 2017 to acclimate krill to dissolved oxygen (DO) or pH conditions.

Author

McLaskey, Anna K., Keister, Julie E., McLaskey, Anna K., and Keister, Julie E.

Abstract

Dataset: Krill Experiment - Experimental Conditions, Seawater conditions monitored and recorded during two separate laboratory experiments in 2017 to acclimate krill to dissolved oxygen (DO) or pH conditions. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/842922, NSF Division of Ocean Sciences (NSF OCE) OCE-1154648

Published
2021

12. Physiological observations of Euphausia pacifica sampled in Puget Sound, WA aboard R/V Clifford A. Barnes during cruises CB1073 and CB1078 in 2017.

Author

McLaskey, Anna K., Keister, Julie E., McLaskey, Anna K., and Keister, Julie E.

Abstract

Dataset: Krill physiology - In situ conditions, Physiological observations of Euphausia pacifica sampled in Puget Sound, WA aboard R/V Clifford A. Barnes during cruises CB1073 and CB1078 in 2017. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/840626, NSF Division of Ocean Sciences (NSF OCE) OCE-1154648

Published
2021

13. CTD profiles acquired in Puget Sound, WA aboard R/V Clifford A. Barnes during cruises CB1073 and CB1078 in 2017.

Author

McLaskey, Anna K., Keister, Julie E., McLaskey, Anna K., and Keister, Julie E.

Abstract

Dataset: CTD casts - Krill cruises, CTD profiles acquired in Puget Sound, WA aboard R/V Clifford A. Barnes during cruises CB1073 and CB1078 in 2017. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/842972, NSF Division of Ocean Sciences (NSF OCE) OCE-1154648

Published
2021

14. Seawater carbonate chemistry and dissolved oxygen of discrete samples taken in Puget Sound, WA during R/V Clifford A. Barnes cruises CB1073 and CB1078 in 2017.

Author

McLaskey, Anna K., Keister, Julie E., McLaskey, Anna K., and Keister, Julie E.

Abstract

Dataset: Bottle data - Krill cruises, Seawater carbonate chemistry and dissolved oxygen of discrete samples taken in Puget Sound, WA during R/V Clifford A. Barnes cruises CB1073 and CB1078 in 2017. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/842728, NSF Division of Ocean Sciences (NSF OCE) OCE-1154648

Published
2021

15. Depth-stratified krill net samples taken in Puget Sound, WA aboard R/V Clifford A. Barnes during cruises CB1073 and CB1078 in 2017.

Author

McLaskey, Anna K., Keister, Julie E., McLaskey, Anna K., and Keister, Julie E.

Abstract

Dataset: Krill densities, Depth-stratified krill net samples taken in Puget Sound, WA aboard R/V Clifford A. Barnes during cruises CB1073 and CB1078 in 2017. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/842831, NSF Division of Ocean Sciences (NSF OCE) OCE-1154648

Published
2021

16. Individual growth rate (IGR) and aminoacyl-tRNA synthetases (AARS) activity as individual-based indicators of growth rate of North Pacific krill, Euphausia pacifica

Author

McLaskey, Anna K., Keister, Julie E., Yebra, Lidia, McLaskey, Anna K., Keister, Julie E., and Yebra, Lidia

Abstract

We investigated aminoacyl-tRNA synthetases (AARS) activity and individual growth rate (IGR) as individual-based in situ indicators of growth in adult krill, Euphausia pacifica. AARS enzymes catalyze the first step in protein synthesis while the IGR method is based on changes in body length during molting. Growth rates of field-collected krill were measured via the IGR method and individuals were subsequently preserved for AARS analysis to yield paired measurements. Our results show that conditions during the IGR incubation period influenced AARS activity in these individuals precluding a direct comparison but revealing the different timescales across which these two measures integrate. Importantly, they show that AARS activity provides a snap-shot image of an organism's metabolism, while IGR of krill is thought to integrate their environmental experience over several days. Each method would require repeated measurements to estimate population growth rates integrated over seasonal or generational time scales. As part of this project, we investigated how specific the AARS assay is to protein synthesis by testing a modified protocol that includes an additional blank and found evidence that the current assay may be measuring other cellular processes in addition to its intended signal. Our results suggest that a new NADH Blank might be optimized to improve the specificity of the assay.

Published
2021

20. Direct and indirect effects of elevated CO2 are revealed through shifts in phytoplankton, copepod development, and fatty acid accumulation.

Author

McLaskey, Anna K., Keister, Julie E., Schoo, Katherina L., Olson, M. Brady, and Love, Brooke A.

Subjects
*PHYTOPLANKTON, *MARINE zooplankton, *FATTY acids
Abstract

Change in the nutritional quality of phytoplankton is a key mechanism through which ocean acidification can affect the function of marine ecosystems. Copepods play an important role transferring energy from phytoplankton to higher trophic levels, including fatty acids (FA)—essential macronutrients synthesized by primary producers that can limit zooplankton and fisheries production. We investigated the direct effects of pCO2 on phytoplankton and copepods in the laboratory, as well as the trophic transfer of effects of pCO2 on food quality. The marine cryptophyte Rhodomonas salina was cultured at 400, 800, and 1200 μatm pCO2 and fed to adult Acartia hudsonica acclimated to the same pCO2 levels. We examined changes in phytoplankton growth rate, cell size, carbon content, and FA content, and copepod FA content, grazing, respiration, egg production, hatching, and naupliar development. This single-factor experiment was repeated at 12°C and at 17°C. At 17°C, the FA content of R. salina responded non-linearly to elevated pCO2 with the greatest FA content at intermediate levels, which was mirrored in A. hudsonica; however, differences in ingestion rate indicate that copepods accumulated FA less efficiently at elevated pCO2. A. hudsonica nauplii developed faster at elevated pCO2 at 12°C in the absence of strong food quality effects, but not at 17°C when food quality varied among treatments. Our results demonstrate that changes to the nutritional quality of phytoplankton are not directly translated to their grazers, and that studies that include trophic links are key to unraveling how ocean acidification will drive changes in marine food webs. [ABSTRACT FROM AUTHOR]

Published
2019
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22. Pressure, O2, and CO2, in aquatic Closed Ecological Systems

Author

Taub, Frieda B. and McLaskey, Anna K.

Subjects
*CLOSED ecological systems (Space environment), *PRESSURE, *PHOTOSYNTHETIC oxygen evolution, *BICARBONATE ions, *PRESUPPOSITION (Logic), *PHOTOSYNTHESIS
Abstract

Abstract: Pressure increased during net photosynthetic O2 production in the light and decreased during respiratory O2 uptake during the dark in aquatic Closed Ecological Systems (CESs) with small head gas volumes. Because most CO2 will be in the liquid phase as bicarbonate and carbonate anions, and CO2 is more soluble than O2, volumes of gaseous CO2 and gaseous O2 will not change in a compensatory manner, leading to the development of pressure. Pressure increases were greatest with nutrient rich medium with NaHCO3 as the carbon source. With more dilute media, pressure was greatest with NaHCO3, and less with cellulose or no-added carbon. Without adequate turbulence, pressure measurements lagged dissolved O2 concentrations by several hours and dark respiration would have been especially underestimated in our systems (250–1000ml). With adequate turbulence (rotary shaker), pressure measurements and dissolved O2 concentrations generally agreed during lights on/off cycles, but O2 measurements provided more detail. At 20°C, 29.9 times as much O2 will distribute into the gas phase as in the liquid, per unit volume, as a result of the limited solubility of O2 in water and according to Henry’s Law. Thus even a small head gas volume can contain more O2 than a larger volume of water. When both dissolved and gaseous O2 and CO2 are summed, the changes in Total O2 and CO2 are in relatively close agreement when NaHCO3 is the carbon source. These findings disprove an assumption made in some of Taub’s earlier research that aquatic CESs would remain at approximately atmospheric pressure because approximately equal molar quantities of O2 and CO2 would exchange during photosynthesis and respiration; this assumption neglected the distribution of O2 between water and gas phases. High pressures can occur when NaHCO3 is the carbon source in nutrient rich media and if head-gas volumes are small relative to the liquid volume; e.g., one “worse case” condition developed 800mmHg above atmospheric pressure and broke the glass container. Plastic screw cap closures are likely to leak at high pressures and should not be assumed to seal unless tested at appropriate pressures. Pressure can be reduced by having larger head-gas volumes and using less concentrated nutrient solutions. It is important that pressure changes be considered for both safety and closure, and if total O2 is used as the measure of net photosynthesis and respiration, the O2 in the gas phase must be added to the dissolved O2. [Copyright &y& Elsevier]

Published
2013
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