DOI: 10.5061/dryad.1vhhmgr07
title: Holopelagic Sargassum aggregations provide warmer microhabitats for associated fauna

description: Drifting aggregations of Sargassum algae provide critical habitat
 for endemic, endangered, and commercially important species. They may also
 provide favorable microclimates for associated fauna. To quantify thermal
 characteristics of holopelagic Sargassum aggregations, we evaluated
 thermal profiles of 50 aggregations in situ in the Sargasso Sea. Sea
 surface temperature (SST) in the center of aggregations was significantly
 higher than in nearby open water, and SST differential was independent of
 aggregation volume, area, and thickness. SST differential between
 aggregation edge and open water was smaller than those between aggregation
 center and aggregation edge and between aggregation center and open water.
 Water temperature was significantly higher inside and below aggregations
 compared to open water but did not vary inside aggregations with
 depth. Holopelagic Sargassum aggregations provide warmer
 microhabitats for associated fauna, which may benefit marine ectotherms,
 though temperature differentials were narrow (up to 0.7 °C) over the range
 of aggregation sizes we encountered (area 0.01–15 m2). We propose a
 hypothetical curve describing variation in SST differential with Sargassum
 aggregation size as a prediction for future studies to evaluate across
 temporal and geographic ranges. Our study provides a foundation for
 investigating the importance of thermal microhabitats in holopelagic
 Sargassum ecosystems.
description: Please see associated metadata file.
description: This Supplement\_metadata.txt file was generated on 2023-09-11 GENERAL
 INFORMATION 1. Title of dataset: Holopelagic Sargassum aggregations
 provide warmer microhabitats for associated fauna 2. Author information:
 Principal investigator contact information (equal first authorship)
 <br> Name: Alexandra G. Gulick Institution: University of Florida,
 Department of Biology Address: 313 Carr Hall, Gainesville, FL 32611 USA
 Email: alexandra.gulick@ufl.edu Alternate email: alexandra\_gulick@nps.gov
 <br> Name: Nerine Constant Institution: University of Florida,
 Department of Biology Address: 313 Carr Hall, Gainesville, FL 32611 USA
 Email: nconstant@ufl.edu 3. Date of data collection: 2019-07 to 2019-08 4.
 Geographic location of data collection: Sargasso Sea (30.3–31.5°N,
 61.7–63.9°W) 5. Information about funding sources that supported the
 collection of the data: Funding was provided by Greenpeace USA and the
 Jeffrey and Monette Fitzsimmons Fund of the University of Florida (UF)
 Archie Carr Center for Sea Turtle Research (ACCSTR). SHARING/ACCESS
 INFORMATION 1. Licenses/restrictions placed on the data: License CCO 1.0
 Universal (CC0 1.0) Public Domain Dedication:
 https://creativecommons.org/publicdomain/zero/1.0/ Dryad Terms of Service:
 https://datadryad.org/stash/terms/view 2. Links to publications that cite
 or use the data: Data and code support the associated publication: Gulick
 AG, Constant N, Bolten AB, Bjorndal KA. (2023) Holopelagic Sargassum
 aggregations provide warmer microhabitats for associated fauna. Scientific
 Reports. https://doi.org/10.1038/s41598-023-41982-w 3. Links to other
 publicly accessible locations of the data: NA 4. Links/relationships to
 ancillary data sets: NA 5. Was data derived from another source? No 6.
 Recommended citation for this dataset: Gulick AG, Constant N, Bolten AB,
 Bjorndal KA. 2023 Holopelagic Sargassum aggregations provide warmer
 microhabitats for associated fauna. Dryad, Dataset, https://doi.org/TBD
 DATA & FILE OVERVIEW 1\. File list: * Supplement\_data.csv --
 Sargassum temperature 2019 dataset * Supplement\_metadata.txt -- Metadata
 for dataset * Supplement\_script.R -- R script used to process the dataset
 for publication 2\. Relationship between files\, if important: NA 3\.
 Additional related data collected that was not included in the current
 data package: NA 4\. Are there multiple versions of the dataset? No
 METHODOLOGICAL INFORMATION 1\. Description of methods used for
 collection/generation of data: Please refer to the associated publication
 for detailed methodology: Gulick AG, Constant N, Bolten AB, Bjorndal KA.
 (2023) Holopelagic Sargassum aggregations provide warmer microhabitats for
 associated fauna. Scientific Reports.
 https://doi.org/10.1038/s41598-023-41982-w 2\. Methods for processing the
 data: We provide raw data of water temperatures measured in Sargassum mats
 and nearby open water in the Sargasso Sea, along with sampling information
 (date, time, location, mat characteristics). We also provide the R script
 used to process data for publication. Please refer to the associated
 publication for detailed methodology: Gulick AG, Constant N, Bolten AB,
 Bjorndal KA. (2023) Holopelagic Sargassum aggregations provide warmer
 microhabitats for associated fauna. Scientific Reports.
 https://doi.org/10.1038/s41598-023-41982-w 3\. Instrument\- or
 software\-specific information needed to interpret the data: NA 4\.
 Standards and calibration information\, if appropriate: NA DATA-SPECIFIC
 INFORMATION FOR: [Supplement\_data.csv] 1\. Number of variables: 93 2\.
 Number of cases/rows: 50 3\. Variable list: * date\_year: Year in which
 temperature measurements were taken for each Sargassum mat and paired open
 water point * date\_mo: Month in which temperature measurements were taken
 for each Sargassum mat and paired open water point * date\_day: Day on
 which temperature measurements were taken for each Sargassum mat and
 paired open water point * time\_collection: Local time (AST, GMT-4) at
 which data collection began for each Sargassum mat and paired open water
 point * latitude: Latitude (decimal degrees) of each Sargassum mat *
 longitude: Longitude (decimal degrees) of each Sargassum mat * mat\_ID:
 Unique alphanumeric identifier for each Sargassum mat in which
 temperatures were measured * mat\_w: Width (m) of each Sargassum mat *
 mat\_l: Length (m) of each Sargassum mat * ow\_0: Water temperature (°C)
 measured at paired open water point at depth of 0 m (sea surface) *
 ow\_0\_t: Local time (AST, GMT-4) of corresponding temperature measurement
 * ow\_0.2: Water temperature (°C) measured at paired open water point at
 depth of 0.2 m * ow\_0.2\_t: Local time of corresponding temperature
 measurement * ow\_0.4: Water temperature (°C) measured at paired open
 water point at depth of 0.4 m * ow\_0.4\_t: Local time (AST, GMT-4) of
 corresponding temperature measurement * ow\_0.6: Water temperature (°C)
 measured at paired open water point at depth of 0.6 m * ow\_0.6\_t: Local
 time (AST, GMT-4) of corresponding temperature measurement * ow\_0.8:
 Water temperature (°C) measured at paired open water point at depth of 0.8
 m * ow\_0.8\_t: Local time (AST, GMT-4) of corresponding temperature
 measurement * ow\_1: Water temperature (°C) measured at paired open water
 point at depth of 1 m * ow\_1\_t: Local time (AST, GMT-4) of corresponding
 temperature measurement * edge\_0: Water temperature (°C) measured at
 Sargassum mat edge at depth of 0 m (sea surface) * edge\_0\_t: Local time
 (AST, GMT-4) of corresponding temperature measurement * edge\_0\_d:
 Sargassum mat thickness (m) at location of corresponding temperature
 measurement * edge\_0.2: Water temperature (°C) measured at Sargassum mat
 edge at depth of 0.2 m * edge\_0.2\_t: Local time (AST, GMT-4) of
 corresponding temperature measurement * edge\_0.2\_d: Sargassum mat
 thickness (m) at location of corresponding temperature measurement *
 edge\_0.4: Water temperature (°C) measured at Sargassum mat edge at depth
 of 0.4 m * edge\_0.4\_t: Local time (AST, GMT-4) of corresponding
 temperature measurement * edge\_0.4\_d: Sargassum mat thickness (m) at
 location of corresponding temperature measurement * edge\_0.6: Water
 temperature (°C) measured at Sargassum mat edge at depth of 0.6 m *
 edge\_0.6\_t: Local time (AST, GMT-4) of corresponding temperature
 measurement * edge\_0.6\_d: Sargassum mat thickness (m) at location of
 corresponding temperature measurement * edge\_0.8: Water temperature (°C)
 measured at Sargassum mat edge at depth of 0.8 m * edge\_0.8\_t: Local
 time (AST, GMT-4) of corresponding temperature measurement * edge\_0.8\_d:
 Sargassum mat thickness (m) at location of corresponding temperature
 measurement * edge\_1: Water temperature (°C) measured at Sargassum mat
 edge at depth of 1 m * edge\_1\_t: Local time (AST, GMT-4) of
 corresponding temperature measurement * edge\_1\_d: Sargassum mat
 thickness (m) at location of corresponding temperature measurement *
 0.5\_0: Water temperature (°C) measured 0.5 m into Sargassum mat at depth
 of 0 m (sea surface) * 0.5\_0\_t: Local time (AST, GMT-4) of corresponding
 temperature measurement * 0.5\_0\_d: Sargassum mat thickness (m) at
 location of corresponding temperature measurement * 0.5\_0.2: Water
 temperature (°C) measured 0.5 m into Sargassum mat at depth of 0.2 m *
 0.5\_0.2\_t: Local time (AST, GMT-4) of corresponding temperature
 measurement * 0.5\_0.2\_d: Sargassum mat thickness (m) at location of
 corresponding temperature measurement * 0.5\_0.4: Water temperature (°C)
 measured 0.5 m into Sargassum mat at depth of 0.4 m * 0.5\_0.4\_t: Local
 time (AST, GMT-4) of corresponding temperature measurement * 0.5\_0.4\_d:
 Sargassum mat thickness (m) at location of corresponding temperature
 measurement * 0.5\_0.6: Water temperature (°C) measured 0.5 m into
 Sargassum mat at depth of 0.6 m * 0.5\_0.6\_t: Local time (AST, GMT-4) of
 corresponding temperature measurement * 0.5\_0.6\_d: Sargassum mat
 thickness (m) at location of corresponding temperature measurement *
 0.5\_0.8: Water temperature (°C) measured 0.5 m into Sargassum mat at
 depth of 0.8 m * 0.5\_0.8\_t: Local time (AST, GMT-4) of corresponding
 temperature measurement * 0.5\_0.8\_d: Sargassum mat thickness (m) at
 location of corresponding temperature measurement * 0.5\_1: Water
 temperature (°C) measured 0.5 m into Sargassum mat at depth of 1 m *
 0.5\_1\_t: Local time (AST, GMT-4) of corresponding temperature
 measurement * 0.5\_1\_d: Sargassum mat thickness (m) at location of
 corresponding temperature measurement * 1\_0: Water temperature (°C)
 measured 1 m into Sargassum mat at depth of 0 m (sea surface) * 1\_0\_t:
 Local time (AST, GMT-4) of corresponding temperature measurement *
 1\_0\_d: Sargassum mat thickness (m) at location of corresponding
 temperature measurement * 1\_0.2: Water temperature (°C) measured 1 m into
 Sargassum mat at depth of 0.2 m * 1\_0.2\_t: Local time (AST, GMT-4) of
 corresponding temperature measurement * 1\_0.2\_d: Sargassum mat thickness
 (m) at location of corresponding temperature measurement * 1\_0.4: Water
 temperature (°C) measured 1 m into Sargassum mat at depth of 0.4 m *
 1\_0.4\_t: Local time (AST, GMT-4) of corresponding temperature
 measurement * 1\_0.4\_d: Sargassum mat thickness (m) at location of
 corresponding temperature measurement * 1\_0.6: Water temperature (°C)
 measured 1 m into Sargassum mat at depth of 0.6 m * 1\_0.6\_t: Local time
 (AST, GMT-4) of corresponding temperature measurement * 1\_0.6\_d:
 Sargassum mat thickness (m) at location of corresponding temperature
 measurement * 1\_0.8: Water temperature (°C) measured 1 m into Sargassum
 mat at depth of 0.8 m * 1\_0.8\_t: Local time (AST, GMT-4) of
 corresponding temperature measurement * 1\_0.8\_d: Sargassum mat thickness
 (m) at location of corresponding temperature measurement * 1\_1: Water
 temperature (°C) measured 1 m into Sargassum mat at depth of 1 m *
 1\_1\_t: Local time (AST, GMT-4) of corresponding temperature measurement
 * 1\_1\_d: Sargassum mat thickness (m) at location of corresponding
 temperature measurement * center\_0: Water temperature (°C) measured at
 Sargassum mat center at depth of 0 m (sea surface) * center\_0\_t: Local
 time (AST, GMT-4) of corresponding temperature measurement * center\_0\_d:
 Sargassum mat thickness (m) at location of corresponding temperature
 measurement * center\_0.2: Water temperature (°C) measured at Sargassum
 mat center at depth of 0.2 m * center\_0.2\_t: Local time (AST, GMT-4) of
 corresponding temperature measurement * center\_0.2\_d: Sargassum mat
 thickness (m) at location of corresponding temperature measurement *
 center\_0.4: Water temperature (°C) measured at Sargassum mat center at
 depth of 0.4 m * center\_0.4\_t: Local time (AST, GMT-4) of corresponding
 temperature measurement * center\_0.4\_d: Sargassum mat thickness (m) at
 location of corresponding temperature measurement * center\_0.6: Water
 temperature (°C) measured at Sargassum mat center at depth of 0.6 m *
 center\_0.6\_t: Local time (AST, GMT-4) of corresponding temperature
 measurement * center\_0.6\_d: Sargassum mat thickness (m) at location of
 corresponding temperature measurement * center\_0.8: Water temperature
 (°C) measured at Sargassum mat center at depth of 0.8 m * center\_0.8\_t:
 Local time (AST, GMT-4) of corresponding temperature measurement *
 center\_0.8\_d: Sargassum mat thickness (m) at location of corresponding
 temperature measurement * center\_1: Water temperature (°C) measured at
 Sargassum mat center at depth of 1 m * center\_1\_t: Local time (AST,
 GMT-4) of corresponding temperature measurement * center\_1\_d: Sargassum
 mat thickness (m) at location of corresponding temperature measurement 4\.
 Missing data codes: Missing data is denoted by "na". 5\.
 Specialized formats or other abbreviations used: NA