Daly Kendra L.

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Daly

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Kendra L.

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Productivity and linkages of the food web of the southern region of the western Antarctic Peninsula continental shelf

( 2013-11-23) Ballerini, Tosca ; Hofmann, Eileen E. ; Ainley, David G. ; Daly, Kendra L. ; Marrari, Marina ; Ribic, Christine A. ; Smith, Walker O. ; Steele, John H.

The productivity and linkages in the food web of the southern region of the west Antarctic Peninsula continental shelf were investigated using a multi-trophic level mass balance model. Data collected during the Southern Ocean Global Ocean Ecosystem Dynamics field program were combined with data from the literature on the abundance and diet composition of zooplankton, fish, seabirds and marine mammals to calculate energy flows in the food web and to infer the overall food web structure at the annual level. Sensitivity analyses investigated the effects of variability in growth and biomass of Antarctic krill (Euphausia superba) and in the biomass of Antarctic krill predators on the structure and energy fluxes in the food web. Scenario simulations provided insights into the potential responses of the food web to a reduced contribution of large phytoplankton (diatom) production to total primary production, and to reduced consumption of primary production by Antarctic krill and mesozooplankton coincident with increased consumption by microzooplankton and salps. Model-derived estimates of primary production were 187 – 207 g C m-2 y-1, which are consistent with observed values (47-351 g C m-2 y-1). Simulations showed that Antarctic krill provide the majority of energy needed to sustain seabird and marine mammal production, thereby exerting a bottom-up control on higher trophic level predators. Energy transfer to top predators via mesozooplanton was a less efficient pathway, and salps were a production loss pathway because little of the primary production they consumed was passed to higher trophic levels. Increased predominance of small phytoplankton (nanoflagellates and cryptophytes) reduced the production of Antarctic krill and of its predators, including seabirds and seals.
Dates of sea ice movement and sea ice distance in McMurdo Sound, Antarctica from MODIS and SSMI imagery between 1978-2015 (McMurdo Predator Prey project)

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2017-07-07) Kim, Stacy ; Daly, Kendra L. ; Ainley, David G. ; Ballard, Grant

Fast/sea ice movement was quantified from visible-wavelength images from the Moderate-resolution Imaging Spectroradiometer (MODIS) aboard the Aqua and Terra satellites (250 m resolution; processing occurred for 2002/03-2014/15 seasons and Terra satellite date from 2000-2002 were not used) and sea ice concentration derived from the Scanning Multichannel Microwave Radiometer- and Special Sensor Microwave Imager-family passive microwave sensors (SSM/I; 25 km resolution; 1978/79-2014/15). MODIS data were acquired in one of two ways, from either processing of Level 1 swath data into “true color” images using SeaDAS software v. 6.4 (2002-2012), or from the Corrected Reflectance (True Color) layers of the NASA Worldview website (http://worldview.earthdata.nasa.gov/; 2012-2015). Fast ice areas were generated manually from clear-sky images by drawing polygons in GIS software; pack ice was excluded from analysis. The fast ice in MODIS images was sometimes obscured by clouds, so for days with missing imagery we interpolated linearly between valid data. From the MODIS imagery, we also measured the direct linear distance between McMurdo Station and the nearest open water. For SSM/I, daily or bi-daily fractional sea ice cover was extracted from data available at the National Snow and Ice Data Center (NSIDC). SSM/I ice concentration was retrieved from the NSDIC web site and ftp site (http://nsidc.org/data/seaice/). To minimize the biases inherent to the different data processing algorithms and in order to reduce the daily variability introduced by the movement of pack ice, we took the maximum of either the Bootstrap or NASATEAM processed values (Comiso, 2000; Cavalieri and others, 2015), and then used a 5-day median filter to smooth changes in sea ice concentration. To further compensate for short-term oscillations we masked ice concentrations greater than 80% when extracting the dates of changes in sea ice cover. For detecting the timing of sea ice changes, sea ice concentrations below 15% were excluded from our analysis, following the methods of Comiso and Steffen (2001).> To simplify discussion in the following, we use the inclusive term “fast/sea ice” to refer to fast ice as determined by MODIS and sea ice as determined by SSM/I. Fast/sea ice area was plotted over time, and the following sequential pattern of fast/sea ice events is identified: (1) initial fast/sea ice retreat from winter maximum; (2) final rapid fast/sea ice retreat to minimum extent; (3) fast/sea ice cover minimum in the entire McMurdo Sound; and (4) fast/sea ice advance. From the MODIS data, we additionally determined (5) fast ice cover minimum on the west side of the Sound; and (6) fast ice cover minimum on the east side of the Sound. For a complete list of measurements, refer to the supplemental document 'Field_names.pdf', and a full dataset description is included in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: http://www.bco-dmo.org/dataset/674819
Icebreaker dates and ice edge distance in McMurdo Sound, Antarctica from austral years 1956/1957 to 2014/2015 (McMurdo Predator Prey project)

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2017-07-07) Kim, Stacy ; Daly, Kendra L. ; Ainley, David G. ; Ballard, Grant

The icebreaker channel from the fast ice edge to McMurdo Station has been created each year since 1956, with the location of the channel remaining consistent, by and large, over the entire period. Dates of the icebreaker arrival at the fast ice edge and/or at McMurdo Station since 1957 were acquired from scientist and icebreaker logbooks and contractor records (DACSUSAP2012-13; pers. comm. P. McGillivary USCG), along with the distance, which was measured by radar from the fast ice edge to McMurdo Station on the date that the icebreaker began breaking fast ice. For a complete list of measurements, refer to the supplemental document 'Field_names.pdf', and a full dataset description is included in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: http://www.bco-dmo.org/dataset/674992
CTD data from McMurdo Sound, Antarctica from 2012 to 2015 (McMurdo Predator Prey project)

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2017-05-11) Daly, Kendra L. ; Kim, Stacy ; Ainley, David G. ; Ballard, Grant

CTD data were collected as part of an ecosystem study in McMurdo Sound, which is located at the southern extent of the Ross Sea in the Southern Ocean. The major goal of this multi-disciplinary project was to assess the influence of top−down forcing (predation) on pelagic zooplankton and fish. During the first year (3 November 2012 – 21 January 2013), the CTD was deployed through ice core holes in the fast ice (sea ice attached to land), sampling from near surface to depths between 97 and 175 m. Stations were located along a transect in the middle of McMurdo Sound, perpendicular to the fast ice edge. In the second year (17 November 2014 – 1 January 2015), CTD casts were deployed between 100 and 254 m in depth, at stations along the fast ice edge, and along three transects into the fast ice along the eastern side of McMurdo Sound (Ross Island), in the middle of the Sound, and on the western side of the Sound. Chlorophyll fluorescence sensor measurements on the CTD casts were only made during the 2014/2015 field expedition. For a complete list of measurements, refer to the supplemental document 'Field_names.pdf', and a full dataset description is included in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: http://www.bco-dmo.org/dataset/680929
Chlorophyll data from McMurdo Sound, Antarctica from 2012 to 2015 (McMurdo Predator Prey project)

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2017-05-11) Daly, Kendra L. ; Ballard, Grant ; Kim, Stacy ; Ainley, David G.

Discrete chlorophyll a data were collected as part of an ecosystem study in McMurdo Sound, which is located at the southern extent of the Ross Sea in the Southern Ocean. The major goal of this multi-disciplinary project was to assess the influence of top−down forcing (predation) on pelagic zooplankton and fish. Samples were collected using Niskin water bottles deployed through the fast ice (sea ice attached to land) during two spring/summer seasons: 3 November 2012 – 21 January 2013 and17 November 2014 – 1 January 2015. Water samples were collected at the surface and in the chlorophyll maximum, when present, as determined by a fluorescence sensor during a CTD cast. During 2012/2013, stations were located along a transect in the middle of McMurdo Sound, perpendicular to the fast ice edge. During 2014/2015, stations were located along the fast ice edge, and along three transects into the fast ice along the eastern side of the McMurdo Sound (Ross Island), in the middle of the Sound, and on the western side of the Sound. For a complete list of measurements, refer to the supplemental document 'Field_names.pdf', and a full dataset description is included in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: http://www.bco-dmo.org/dataset/679685
Zooplankton abundance with developmental stages from MOCNESS nets from the ARSV Laurence M. Gould LMG0104, LMG0203 from the Southern Ocean, 2001-2002 (SOGLOBEC project)

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2019-02-06) Daly, Kendra L.

Zooplankton abundance with developmental stages from MOCNESS nets from the ARSV Laurence M. Gould LMG0104, LMG0203 from the Southern Ocean, 2001-2002. 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/2386
Chlorophyll data (CTD water bottle data) from ARSV Laurence M. Gould cruise LMG0203 in the Southern Ocean in 2002 (SOGLOBEC project)

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2019-11-20) Daly, Kendra L.

Chlorophyll data (CTD water bottle data) from ARSV Laurence M. Gould cruise LMG0203 in the Southern Ocean in 2002 (SOGLOBEC project) 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/2357
Euphausiid abundance and size distribution (MOCNESS) from the ARSV Laurence M. Gould LMG0104, LMG0203 from the Southern Ocean, 2001-2002 (SOGLOBEC project)

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2019-03-13) Daly, Kendra L.

Euphausiid abundance and size distribution (MOCNESS) from the ARSV Laurence M. Gould LMG0104, LMG0203 from the Southern Ocean, 2001-2002 during the Sothern Ocean GLOBEC project. 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/2366
Acoustic backscatter from krill and silverfish in McMurdo Sound from 2014-2015

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2018-03-19) Daly, Kendra L. ; Saenz, Benjamin ; Kim, Stacy

Acoustic echosounder data were collected as part of an ecosystem study in McMurdo Sound, which is located at the southern extent of the Ross Sea in the Southern Ocean. The major goal of this multi-disciplinary project was to assess the influence of top−down forcing (predation) on pelagic zooplankton and fish. Stations were located along the fast ice edge, and along three transects into the fast ice along the eastern side of McMurdo Sound (Ross Island), in the middle of the Sound, and on the western side of the Sound. Krill and fish were sampled between 17 November 2014 – 1 January 2015, both acoustically and visually beneath the fast ice using the tethered SCINI ROV, which was deployed and operated through a 25 cm diameter hole drilled through the sea ice. SCINI contained cameras and thrusters, and towed a sensor package consisting of a WET Labs fluorometer (ECO-AFL/FL) and a single-beam Biosonics 120 kHz DT-X echosounder. Visual targets were identified to the lowest taxon possible; these observations were used primarily to verify classification of acoustic signals. The echosounder operated at a nominal ping rate of 1 ping s-1; however, this rate was occasionally adjusted if false bottom signals were observed. The general profile of a dive included a surface transect of ~300 m horizontal distance, where the acoustic transducer faced downward, and also a dive to ~120 m if conditions allowed. Echogram data were saved to a depth of 500 m, and background noise was removed. Given the effective range of the transducer of approximately 100 m (resolving -80 dB targets), surveys characterized the upper 200 m of the water column.Raw acoustic data were analyzed using Echoview software (version 5.3). All acoustic aggregations greater than 4 pings in width were manually delineated, and acoustic energy of the aggregations was integrated into bins of six seconds wide by 1 m in depth. These aggregations were classified as potentially krill or silverfish, based upon ROV visual identification of the targets or, where no visual targets were encountered, by comparing the aggregation target strength, shape, density, and texture and depth to a set of aggregations with positive visual classification. Data are provided for every 10 m depth by six second acoustic bin, for each site, with only classified krill or silverfish backscatter in the bins. Zero data is also reported, to allow estimation of density parameters. Acoustic returns are presented as integrated acoustic energy (volume backscatter strength [Sv], in units of dB re m-1). For a complete list of measurements, refer to the supplemental document 'Field_names.pdf', and a full dataset description is included in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: http://www.bco-dmo.org/dataset/715715
Acoustic backscatter from sites in McMurdo Sound from 2014-2015 (McMurdo Predator Prey project)

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2018-03-19) Daly, Kendra L. ; Saenz, Benjamin ; Kim, Stacy

Acoustic echosounder data were collected as part of an ecosystem study in McMurdo Sound, which is located at the southern extent of the Ross Sea in the Southern Ocean. The major goal of this multi-disciplinary project was to assess the influence of top−down forcing (predation) on pelagic zooplankton and fish. Stations were located along the fast ice edge, and along three transects into the fast ice along the eastern side of McMurdo Sound (Ross Island), in the middle of the Sound, and on the western side of the Sound. Krill and fish were sampled between 17 November 2014 – 1 January 2015, both acoustically and visually beneath the fast ice using the tethered SCINI ROV, which was deployed and operated through a 25 cm diameter hole drilled through the sea ice. SCINI contained cameras and thrusters, and towed a sensor package consisting of a WET Labs fluorometer (ECO-AFL/FL) and a single-beam Biosonics 120 kHz DT-X echosounder. Raw acoustic data were analyzed using Echoview software (version 5.3). All acoustic aggregations greater than 4 pings in width were manually delineated, and acoustic energy of the aggregations was integrated into bins of six seconds wide by 1 m in depth. These aggregations were classified as potentially krill or silverfish, based upon ROV visual identification of the targets or, where no visual targets were encountered, by comparing the aggregation target strength, shape, density, and texture and depth to a set of aggregations with positive visual classification. Visual targets were identified to the lowest taxon possible; these observations were used primarily to verify classification of acoustic signals. The echosounder operated at a nominal ping rate of 1 ping s-1; however, this rate was occasionally adjusted if false bottom signals were observed. The general profile of a dive included a surface transect of ~300 m horizontal distance, where the acoustic transducer faced downward, and also a dive to ~120 m if conditions allowed. Echogram data were saved to a depth of 500 m, and background noise was removed. Given the effective range of the transducer of approximately 100 m (resolving -80 dB targets), surveys characterized the upper 200 m of the water column. Finally, all classified volume backscatter values were summed, station means were calculated. Acoustic returns are presented as integrated acoustic energy (volume backscatter strength [Sv], in units of dB re m-1). For a complete list of measurements, refer to the supplemental document 'Field_names.pdf', and a full dataset description is included in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: http://www.bco-dmo.org/dataset/715512
Climate impacts on zooplankton population dynamics in coastal marine ecosystems

(The Oceanography Society, 2013-12) Batchelder, Harold P. ; Daly, Kendra L. ; Davis, Cabell S. ; Ji, Rubao ; Ohman, Mark D. ; Peterson, William T. ; Runge, Jeffrey A.

The 20-year US GLOBEC (Global Ocean Ecosystem Dynamics) program examined zooplankton populations and their predators in four coastal marine ecosystems. Program scientists learned that environmental controls on zooplankton vital rates, especially the timing and magnitude of reproduction, growth, life-cycle progression, and mortality, determine species population dynamics, seasonal and spatial distributions, and abundances. Improved knowledge of spatial-temporal abundance and distribution of individual zooplankton taxa coupled with new information linking higher trophic level predators (salmon, cod, haddock, penguins, seals) to their prey yielded mechanistic descriptions of how climate variation impacts regionally important marine resources. Coupled ecological models driven by improved regional-scale climate scenario models developed during GLOBEC enable forecasts of plausible future conditions in coastal ecosystems, and will aid and inform decision makers and communities as they assess, respond, and adapt to the effects of environmental change. Multi-region synthesis revealed that conditions in winter, before upwelling, or seasonal stratification, or ice melt (depending on region) had significant and important effects that primed the systems for greater zooplankton population abundance and productivity the following spring-summer, with effects that propagated to higher trophic levels.
Sea ice parameters near McMurdo Station, Antarctica from 1986 to 2013

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2017-07-07) Kim, Stacy ; Daly, Kendra L. ; Ainley, David G. ; Ballard, Grant

Fast ice thickness and temperature data collected at the “sea ice runway” near McMurdo Station by the United States Antarctic Program (USAP) logistic support contractors and provided by the Ice Surveyor (J Scanniello). Fast ice measurements were taken at a suite of 16 stations along a 3000 m distance, and five stations across an orthogonal 1000 m distance. At each station, small holes were drilled through the fast ice and the thickness measured using a meter tape with a lever-arm that held the zero-point against the bottom of the fast ice. Thickness was measured for solid ice and did not include underlying platelet ice, nor overlying snow. Fast ice temperature was measured at 15 cm depth beneath the ice surface. Note that the sea ice runway area is routinely cleared of excess snow, which may affect the fast ice thickness and temperature measurements. For a complete list of measurements, refer to the supplemental document 'Field_names.pdf', and a full dataset description is included in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: http://www.bco-dmo.org/dataset/675187
Underway chlorophyll data from RVIB Nathaniel B. Palmer and ARSV Laurence M. Gould cruises NBP0104, LMG0203, and NBP0204 in the Southern Ocean from 2001-2002 (SOGLOBEC project)

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2019-03-04) Daly, Kendra L.

Underway chlorophyll data from RVIB Nathaniel B. Palmer and ARSV Laurence M. Gould cruises NBP0104, LMG0203, and NBP0204 in the Southern Ocean from 2001-2002 (SOGLOBEC project) 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/2358
Dates of sea ice movement and sea ice distance in McMurdo Sound, Antarctica from MODIS and SSMI imagery between 1978-2015

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2020-02-21) Kim, Stacy ; Ainley, David G. ; Ballard, Grant ; Daly, Kendra L.

This dataset contains dates relevant to sea ice movement including dates of initial ice retreat, final ice retreat, ice minimum, general ice minimum, ice minimum for the west of McMurdo Sound, ice minimum for the east of McMurdo Sound, and refreeze start. It also includes the minimum distance to the ice edge from McMurdo Station. Dates were derived from Moderate-resolution Imaging Spectroradiometers (MODIS) collected between 2003 and 2015 and Scanning Multichannel Microwave Radiometer and Special Sensor Microwave Imager-family passive microwave sensors (SSM/I) imagery collected between 1978 and 2015. 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/674819

Daly Kendra L.

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