uid=MCM,o=EDI,dc=edirepository,dc=org all public read bnthchla Ian Hawes ian.hawes@waikato.ac.nz https://sci.waikato.ac.nz/about-us/people/ihawes https://orcid.org/0000-0003-2471-6903 McMurdo Dry Valleys LTER http://mcmlter.org/ Inigo San Gil

Department of Biology, MSC03 2020 University of New Mexico Albuquerque NM 87131 US

(505) 277-2625 (505) 277-2541 isangil@lternet.edu data manager 2014-11-11 English

As part of the Long Term Ecological Research (LTER) project in the McMurdo Dry Valleys of Antarctica, the growth of benthic cyanobacteria-dominated mats in the lakes have been monitored. This dataset shows chlorophyll-a levels associated with the benthic mats. Values are provided for various depths of Lake Hoare during the 1996-97 field season, both with and without correction for phaeopigments.

benthos chlorophyll a lakes limnology LTER Controlled Vocabulary benthic chlopophyl-A lake limnology McMurdo Dry Valleys phaeopigments Station Keywords organic matter LTER Core Areas The data were obtained by Dr. Ian Hawes of the National Institute of Water and Atmospheric Research, Christchurch New Zealand ( ), who should be contacted with any queries. The research was funded by the New Zealand Foundation for Research, Science and Technology, under grant CO1601. Logistic support was provided by the Taylor Valley Long Term Ecological Research Program.

This data package is released under the Creative Commons Attribution 4.0 International License (CC BY 4.0; http://creativecommons.org/licenses/by/4.0/), which allows consumers (hereinafter referred to as “Data Users”) to freely reuse, redistribute, transform, or build on this work (even commercially) so long as appropriate credit is provided. Accordingly, Data Users are required to properly cite this data package in any publications or in the metadata of any derived products that result from its use (in whole or in part). A recommended citation is provided on the summary metadata page associated with this data package in the McMurdo Dry Valleys LTER Data Catalog (https://mcmlter.org/data), and a generic citation may be found on the summary metadata page in the repository where this data package was obtained. When these data contribute significantly to the contents of a publication, Data Users must also acknowledge that data were provided by the NSF-supported McMurdo Dry Valleys Long Term Ecological Research program (OPP-2224760). This data package has been released in the spirit of open scientific collaboration. Hence, Data Users are strongly encouraged to consider consultation, collaboration, and/or co-authorship (as appropriate) with the data package creator(s). Data Users should be aware these data may be actively used by others for ongoing research; thus, coordination may be necessary to prevent duplicate publication. Data Users should also recognize that misinterpretation of data may occur if they are used outside the context of the original study. Hence, Data Users are urged to contact the data package creator(s) if they have any questions regarding methodology or results. While substantial efforts are made to ensure the accuracy of this data package (with all its components), complete accuracy cannot be guaranteed. Periodic updates to this data package may occur, and it is the responsibility of Data Users to check for new versions. This data package is made available “as is” and comes with no warranty of accuracy or fitness for use. The creator(s) of this data package and the repository where these data were obtained shall not be liable for any damages resulting from misinterpretation, use, or misuse of these data. Finally, as a professional courtesy, we kindly request Data Users notify the primary contact referenced in the metadata when these data are used in the production of any derivative work or publication. Notification should include an explanation of how the data were used, along with a digital copy of the derived product(s). Thank you.

https://mcm.lternet.edu/content/chlorophyll-concentrations-lake-hoare-benthic-mats-1996-97 Lake Hoare occupies a narrower portion of the Taylor Valley, dammed by the Canada Glacier. It would drain almost completely without this dam. There are a number of islands which may be related to an old terminal of Canada Glacier. The lake is fed primarily from direct runoff from the glacier, as well as meltwater streams. (Lake level rose ~1.5 m between 1972 and 1996). There are no surface outflows; the only known water loss is through ice ablation (evaporation, sublimation and physical scouring). Valley: Taylor Distance to Sea : 15 Maximum Length (km): 4.2 Maximum Width (km): 1 Maximum Depth (m): 34 Surface Area (km^2): 1.94 Ice Thickness Average Surface (m): 3.1 - 5.5 Volume (m^3 * 10^6): 17.5 162.784423828125 162.935836791992 -77.623085021973 -77.639259338379 73 73 meter 1996-12-01 1996-12-31 Metadata completed in 2016Data and metadata migrated into the Drupal Ecological Information Management System in 2014. (San Gil) McMurdo Dry Valleys LTER http://mcmlter.org/ McMurdo Dry Valleys LTER http://mcmlter.org/ McMurdo Dry Valleys LTER

These data are based on analysis of replicated 1.98 cm2 cores of the pigmented surface layer of benthic microbial mats from Lake Hoare. Parallel experiments in which thicker cores were sectioned showed that this surface layer contained all chlorophyll-a present in the cores. They are expressed per unit area of core, units andmicro;g/cm2 (micrograms per square centimeter). All depths refer to depth from the surface and are in meters. Samples were obtained from an approximately linear transect stretching from the Lake Hoare laboratory complex towards the lake deepspot. Cores were collected through December 1996 by scuba divers. Initially, cores of 7 cm diameter were collected using sharpened perspex coring tubes. After retrieval to the surface, these were subsampled using sharpened, cut-off syringe barrels. Cores were stored at -20anddeg;C, in the dark, until processed in New Zealand some 2-3 months later. Extraction was into 10 ml of 90% acetone (allowing for volume of water in core), and was aided by grinding with a teflon pestle in a glass tube. Calculations were based on absorptance of the extract measured at 665, corrected by subtracting that at 750 nm. Correction for phaeopigments was accomplished by re-measuring absorptance after acidification with dilute HCl. Equations used for calculating chlorophyll-a in andmicro;m/cm2 with (Eq 1) and without (Eq 2) correction for phaeopigments were: Eq 1: (A665(na)-A665(ac)) x 27.3 x 1/vol x 1/area Eq 2: A665(na) x 11.23 x 1/vol x 1/area where A665(na) and A665(ac) are corrected absorptances (as optical density) before and after acidification, vol is volume of acetone used (ml) and area is the area of the core (cm2).

bnthchla Columns descriptions, labels, parameter definitions, units. bnthchla.csv 6541 1 0 \n column , " https://mcm.lternet.edu/sites/default/files/bnthchla.csv Location Location Name of lake where measurement was made string Name of lake where measurement was made Season Season Season sampled string Season sampled Depth (m) Depth (m) Depth at which sample was drawn from lake meter 1 real Total chl-a (ug/cm2) Total chl-a (ug/cm2) Chlorophyll-a concentration micrograms/cm2 real NULL None given Avg chl-a (ug/cm2) Avg chl-a (ug/cm2) Average Chlorophyll-a concentration micrograms/cm2 real NULL None given CHL-A COR FOR PHAEO(ug/cm2) Chl-a corrected for phaeopigments (ug/cm2) Chl-a corrected for phaeopigments (ug/cm2) micrograms/cm2 real NULL None given AVG CHL-A COR PHAEO(ug/cm2) Average Chl-a corrected for phaeopigments (ug/cm2) Average Chl-a corrected for phaeopigments (ug/cm2) micrograms/cm2 real NULL None given File Name File Name Original file name before entered into database string Original file name before entered into database