Chlorophyll data from McMurdo Sound, Antarctica from 2012 to 2015 (McMurdo Predator Prey project)

Version Date: 2017-02-08

» Food web dynamics in an intact ecosystem: the role of top predators in McMurdo Sound (McMurdo Predator Prey)
Daly, Kendra L.University of South Florida (USF)Principal Investigator, Contact
Ainley, David G.H.T. Harvey & AssociatesCo-Principal Investigator
Ballard, GrantPoint Blue Conservation ScienceCo-Principal Investigator
Kim, StacyMoss Landing Marine Laboratories (MLML)Co-Principal Investigator
York, Amber D.Woods Hole Oceanographic Institution (WHOI BCO-DMO)BCO-DMO Data Manager


Spatial Extent: N:-77.5843 E:166.0604 S:-77.6722 W:165.8024
Temporal Extent: 2012-11-12 - 2015-01-09

Dataset Description

This dataset includes chlorophyll, phaeopigments, depth, lat, lon, and station from McMurdo Sound, Antarctica collected between the austral years 2012/2013 and 2014/2015.

Methods & Sampling

Small holes were drilled through the McMurdo Sound fast ice. A Niskin Bottle was deployed below the fast ice and water was collected just below the ice-water interface and at a pre-determined depth (Chlorophyll maximum) as determined by a fluorescence sensor on a CTD. Water samples from the Niskin bottles were collected in 4 L amber Nalgene bottles and then immediately stored in a dark cooler. Gloves were worn for sample collection and bottles and caps were rinsed three times before sample collection. The sample bottles were immediately processed as soon as they returned from the field. The collection bottle was gently swirled and 50 to 2000 mL were filtered under low vacuum onto a 25 mm GF/F filter. Filters were immediately placed in 13 mm borosilicate test tubes containing 7 mL 90% v/v HPLC grade acetone and extracted in the dark for 24 h at -20 degrees C. After extraction, fluorescence was measured with a Turner Designs 10 AU fluorometer before and after acidification. The fluorometer was calibrated at McMurdo Station at the beginning of the field season using Chlorophyll a standards from Sigma-Aldrich and rechecked using a solid standard from Turner Designs several times during the field season. Chlorophyll a was determined using the methods of Parsons et al. (1984).

Parsons, T.R., Maita, Y., Lalli, C.M., 1984. A Manual of Chemical and Biological Methods for Seawater Analysis. Pergamon Press, New York, pp. 107–110.

Data Processing Description

BCO-DMO Data Manager Processing Notes:
* added a conventional header with dataset name, PI name, version date
* modified parameter names to conform with BCO-DMO naming conventions
* blank values replaced with no data value 'nd'
* changed all dates to yyyy-mm-dd that were not already

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Data Files

(Comma Separated Values (.csv), 9.22 KB)
Primary data file for dataset ID 679685

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stationCTD station name where niskin bottle sample acquired unitless
dateDate in format yyyy-mm-dd in local time (UTC+12) unitless
latLatitude of CTD cast; north is positive decimal degrees
lonLongitude of CTD cast; west is negative decimal degrees
depthDepth of sample meters
chlChlorophyll a micrograms per liter (ug/L)
phaeoPhaeopigments micrograms per liter (ug/L)

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Dataset-specific Instrument Name
Generic Instrument Name
Niskin bottle
Generic Instrument Description
A Niskin bottle (a next generation water sampler based on the Nansen bottle) is a cylindrical, non-metallic water collection device with stoppers at both ends. The bottles can be attached individually on a hydrowire or deployed in 12, 24, or 36 bottle Rosette systems mounted on a frame and combined with a CTD. Niskin bottles are used to collect discrete water samples for a range of measurements including pigments, nutrients, plankton, etc.

Dataset-specific Instrument Name
Generic Instrument Name
Wet Labs ECO-AFL/FL Fluorometer
Generic Instrument Description
The Environmental Characterization Optics (ECO) series of single channel fluorometers delivers both high resolution and wide ranges across the entire line of parameters using 14 bit digital processing. The ECO series excels in biological monitoring and dye trace studies. The potted optics block results in long term stability of the instrument and the optional anti-biofouling technology delivers truly long term field measurements. more information from Wet Labs

Dataset-specific Instrument Name
Generic Instrument Name
CTD Sea-Bird SBE SEACAT 19plus
Generic Instrument Description
Self contained self powered CTD profiler. Measures conductivity, temperature and pressure in both profiling (samples at 4 scans/sec) and moored (sample rates of once every 5 seconds to once every 9 hours) mode. Available in plastic or titanium housing with depth ranges of 600m and 7000m respectively. Minature submersible pump provides water to conductivity cell.

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McMurdo Station
Start Date
End Date

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Project Information

Food web dynamics in an intact ecosystem: the role of top predators in McMurdo Sound (McMurdo Predator Prey)

Coverage: McMurdo Sound, Antarctica

Extracted from the NSF award abstract:

The research project investigates the importance of top down forcing on pelagic food webs. The relatively pristine Ross Sea includes large populations of upper-level predators such as minke and killer whales, Adélie and Emperor penguins, and Antarctic toothfish. This project focuses on food web interactions of Adélie penguins, minke whales, and the fish-eating Ross Sea killer whales, all of which exert foraging pressure on their main prey, crystal krill (Euphausia cyrstallorophias) and silver fish (Pleuragramma antarcticum) in McMurdo Sound.

The investigators used a video- and acoustic-capable ROV, and standard biological and environmental sensors to quantify the abundance and distribution of phytoplankton, sea ice biota, prey, and relevant habitat data.  The sampling area included 37 stations across an 30 x 15 km section of McMurdo Sound, stratified by distance from the ice edge as a proxy for air-breathing predator access. This study will be among the first to assess top-down forcing in the Ross Sea ecosystem and will form the basis for multidisciplinary studies in the future.

Map sampling stations


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Funding SourceAward
NSF Division of Polar Programs (NSF PLR)

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