http://lod.bco-dmo.org/id/dataset/1000920 eng; USA utf8 dataset Highest level of data collection, from a common set of sensors or instrumentation, usually within the same research project Biological and Chemical Oceanography Data Management Office (BCO-DMO) Unavailable 508-289-2009 WHOI MS#36 Woods Hole MA 02543 USA info@bco-dmo.org http://www.bco-dmo.org Monday - Friday 8:00am - 5:00pm For questions regarding this resource, please contact BCO-DMO via the email address provided. pointOfContact 2026-06-11 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) Nereocystis luetkeana geographic patterns in physiology and microbiome from samples collected from 2019 to 2022 at nine sites spanning more than 200 kilometers in Washington state 2026-06-17 publication 2026-06-17 revision BCO-DMO Linked Data URI 2026-06-17 creation http://lod.bco-dmo.org/id/dataset/1000920 Catherine Ann Pfister University of Chicago principalInvestigator Biological and Chemical Oceanography Data Management Office (BCO-DMO) Unavailable 508-289-2009 WHOI MS#36 Woods Hole MA 02543 USA info@bco-dmo.org http://www.bco-dmo.org Monday - Friday 8:00am - 5:00pm For questions regarding this resource, please contact BCO-DMO via the email address provided. publisher Cite this dataset as: Pfister, C. A. (2026) Nereocystis luetkeana geographic patterns in physiology and microbiome from samples collected from 2019 to 2022 at nine sites spanning more than 200 kilometers in Washington state. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 1) Version Date 2026-06-17 [if applicable, indicate subset used]. http://lod.bco-dmo.org/id/dataset/1000920 [access date] Nereocystis geographic patterns in physiology and microbiome Dataset Description: Methods and Sampling: &lt;p&gt;These are data on kelp traits, seawater features and 16S rRNA amplicon sequencing. All kelp measurements were made in situ, often via kayak or at the shore using a measuring tape and calipers.&lt;/p&gt; &lt;p&gt;Kelp tissue was collected for elemental analysis by excising a 2 x 2 centimeter (cm) piece of tissue in the meristematic region. Tissue was ground to a fine powder in a GenoGrinder Spex (Metuchen, NJ), weighed in aliquots of 1.2 to 1.5 milligrams (mg) and packed into 3.5 × 5 millimeter (mm) aluminium tins (Costech, Valencia, CA). Packed tins were analysed on an elemental analyser isotope ratio mass spectrometer at Northwestern University Stable Isotope Biogeochemistry Laboratory (NUSIBL).&lt;/p&gt; &lt;p&gt;Carbon fixation was quantified using a section of the youngest, basal frond tissue extending 24 to 30 cm from the bulb. It was weighed (wet mass in grams (g)) with a Pesola scale and placed in a 1 liter (L) Nalgene container; the change in oxygen was measured for 1 hour with a Pyro Science contactless fibre-optic sensors (Oxygen Sensor Spots OXSP5) and an optical oxygen and temperature meter (FireStingO2 FSO2-4), with the sensor spots affixed inside each 1 L chamber.&lt;/p&gt; &lt;p&gt;DOC release and nutrient changes were quantified from seawater filtered through a GF/F filter and immediately frozen for analysis at the University of Washington Marine Chemistry Laboratory (methods from UNESCO), with DOC samples frozen in 40 milliliter (mL) glass vials with Teflon caps (Shimadzu, VOA) and other nutrients in acid-washed 60 mL high density polyethylene (HDPE) Nalgene bottles.&lt;/p&gt; &lt;p&gt;Using pulse amplitude modulated (PAM) fluorometry &lt;em&gt;in situ&lt;/em&gt; (Diving Pam, Walz, Germany) we estimated fluorescence over a range of irradiances. PAM is a non-invasive, &lt;em&gt;in situ&lt;/em&gt; method that quantifies Photosystem II fluorescence parameters across different light levels. Tissue was dark-adapted for 20 minutes and then rapid light curves were estimated with nine PAR levels from 0 to 1200. We estimated the maximum electron transport rate (ETR&lt;sub&gt;max&lt;/sub&gt;) and the photosynthetic efficiency at low light, both as the initial linear slope of ETR to irradiance (&lt;em&gt;α&lt;/em&gt;) and as the quantum yield of photosystem II (Yield) on nine individual &lt;em&gt;Nereocystis&lt;/em&gt; at both Tatoosh Island and Squaxin Island, the populations that span the greatest range of environmental conditions. Tatoosh Island was assayed on 9 and 20 June 2019 and Squaxin Island on 2 July 2019. At both sites, we selected individuals at least 1 meter (m) apart at low tide.&lt;/p&gt; &lt;p&gt;The salinity and seawater temperatures were assessed with a Castaway-CTD (Sontek) from a boat or kayak at all sites except Tatoosh Island where instrumentation is moored (Hach DS5).&lt;/p&gt; &lt;p&gt;Microbial density on individual kelp blades at either end of the geographic distribution, Tatoosh Island versus Squaxin Island, differed using 4,6-diamidino-2-phenylindole (DAPI) fluorescent staining of bacterial cells. We quantified bacterial cells from a section of the blade at approximately 20 cm distal from where the blade articulates with the bulb. We sampled a 3−5 mm slice from 10 individuals at each site (Tatoosh on 4 August 2019, Squaxin on 2 July 2019), preserving each slice immediately in Formalin, transferring to 50 : 50 EtOH : phosphate-buffered saline (PBS) after 1 hour, then freezing. In the laboratory, each piece was again sliced with a razor blade to approximately 0.5 mm, placed on a glass slide, and a solution of 1 microgram (µg) DAPI : 1 mL PBS was dropped on the slide-mounted slice. The slide was kept in dark for 20 minutes, chilled and rinsed with PBS prior to visualizing at 100× with an Olympus BX50 fluorescence microscope with a DAPI filter. We photographed 10 fields of view, selected haphazardly, for each individual slice, resulting in 100 images at each Tatoosh and Squaxin. In samples where bacteria were sparse or non-existent, we repeatedly adjusted the fine focus to verify no bacteria were present. We quantified the bacteria in ImageJ, enumerating the cells in the blue channel, adjusting the background and thresholds identically for all 200 images to eliminate autofluorescence by kelp cells. We calculated bacterial cell density as a percentage of the total imaged area.&lt;/p&gt; &lt;p&gt;Individual kelp was sampled for microbes by rubbing a cotton swab for 20−30 seconds over the mid-blade region. The swab was placed in a 2 mL Eppendorf tube, immediately chilled and transferred to a freezer within 4−6 hours. DNA from the swabs was extracted with a Qiagen DNeasy PowerSoil Kit (Qiagen). DNA was amplified, sequenced and amplicon sequence variants (ASVs) were identified by the Duchossois Family Institute Microbial Metagenomics Facility (DFIMMF) at The University of Chicago. The V4–V5 region within the 16S ribosomal RNA (rRNA) gene was amplified using universal bacterial primers and polymerase chain reaction (PCR) conditions described in Younker, et al. (2024). Approximately 412 bp region amplicons were then purified using a spin column-based method (Minelute, Qiagen), quantified and dual index adapters were ligated. Sequences were generated from the Illumina MiSeq platform using the QIASeq 1-step amplicon kit (Qiagen) for generating libraries and using 2 × 250 paired end reads with 5000 to 10,000 reads per sample. The default pipeline for processing MiSeq 16S rRNA reads was dada2 (v. 1.18.0) with minor modifications in R (v. 4.0.3). Reads were first trimmed at 190 bp for both forward and reverse reads to remove low-quality nucleotides, and chimaeras were detected and removed using the default consensus method in the dada2 pipeline. Then, ASVs with length between 320 and 365 bp were retained. Taxonomy of the resultant ASVs were assigned to the genus level using the RDP classifier (v. 2.13) with a minimum bootstrap confidence score of 80. Species-level classification used blastn (v. 2.13.0) and the refseq_rna database. We analysed ASVs with R, phyloseq and microViz (R version 2023.06.2+561). Chloroplast DNA that was not classified as Cyanobacteria were generally diatoms (Bacillarophyta) and were filtered out, as well as any other chloroplast sequence that did not match to the class Cyanobacteria. Sequences of corn (Zea, in Plantae), in low numbers at some Puget Sound sites, were also removed.&lt;/p&gt; &lt;p&gt;All methods are described in the Pfister, et al. (2025) paper.&lt;/p&gt; Funding provided by NSF Division of Ocean Sciences (NSF OCE) Award Number: OCE-2329475 Award URL: https://www.nsf.gov/awardsearch/show-award?AWD_ID=2329475 onGoing Catherine Ann Pfister University of Chicago 773-834-0071 Department of Ecology and Evolution 1101 E 57th St Chicago IL 60637 USA cpfister@uchicago.edu pointOfContact asNeeded Dataset Version: 1 Unknown year date month locale region latitude longitude replicate wetmass_g drymass_g mgCfixed_gdrymass_hr DOCmgl_release_gdrymass_hr_corr01 DOC_um_hr_drymass to_po4 to_si to_no3 to_no2 to_nh4 to_DIN uM_DOC_to tf_po4 tf_si tf_no3 tf_no2 tf_nh4 tf_DIN no3_uptake_h_gdm bulb_diam blade_length repro deln delc pctn pctc c_n temperature salinity ratioCfixtoDOCrel Illumina MiSeq calipers Qiagen DNeasy PowerSoil Kit (Qiagen) Olympus BX50 fluorescence microscope pulse amplitude modulated (PAM) fluorometry in situ (Diving Pam, Walz, Germany) GenoGrinder Spex elemental analyser isotope ratio mass spectrometer measuring tape optical oxygen and temperature meter (FireStingO2 FSO2-4) Oxygen Sensor Spots (OXSP5) Pesola scale Castaway-CTD (Sontek) polymerase chain reaction (PCR) Hach DS5 theme None, User defined year date month of year site latitude longitude replicate mass Elemental carbon (C) dissolved organic Carbon phosphate Silicate (reactive silica) Nitrate Nitrite Ammonium Dissolved Inorganic Nitrogen diameter length sample description d15N measured in biota d13C measured in biota Nitrogen Carbon to Nitrogen ratio (C:N) water temperature at measurement depth salinity ratio featureType BCO-DMO Standard Parameters Automated DNA Sequencer calipers DNA Analysis Kit Fluorescence Microscope Fluorometer Homogenizer Isotope-ratio Mass Spectrometer Measuring Tape Oxygen Sensor Oxygen Sensor Spot scale or balance SonTek CastAway-CTD Thermal Cycler Water Quality Multiprobe instrument BCO-DMO Standard Instruments otherRestrictions otherRestrictions Access Constraints: none. Use Constraints: Please follow guidelines at: http://www.bco-dmo.org/terms-use Distribution liability: Under no circumstances shall BCO-DMO be liable for any direct, incidental, special, consequential, indirect, or punitive damages that result from the use of, or the inability to use, the materials in this data submission. If you are dissatisfied with any materials in this data submission your sole and exclusive remedy is to discontinue use. The role of microbes in driving productivity and carbon fixation in seaweeds https://pfisterlab.uchicago.edu/basic-page/ The role of microbes in driving productivity and carbon fixation in seaweeds <p><em>NSF Award Abstract:</em><br /> It is increasingly recognized that species in the ocean host a diverse set of microbes and that these microbes can determine the functioning of the host. Yet, the discovery of microbial taxa in nature far outpaces our understanding of their functions. Primary producers in the ocean show rich microbial communities and may contribute to the significant role that macrophytes play in coastal communities. This project focuses on a species of canopy kelp that is a foundational species along the shores of the northeast Pacific Ocean, the bull kelp <em>Nereocystis luetkeana</em>. The research explores the role of a diverse set of microbes in association with bull kelp. Using experimental manipulations of newly isolated microbial taxa from kelp, tests of whether interactions are positive, negative, or neutral are performed. Specific assays of whether microbes provision vitamins and enhance access to nutrients are carried out, as well as tests of whether kelp exudates benefit microbial metabolism and growth. Working directly with Tribal youth through an internship program, as well as with undergraduate, post-baccalaureate, and graduate students, helps train the next generation of ocean scientists. Communication channels with Tribal and State governments inform efforts to understand kelp declines. Host-microbe interactions are a component of the persistence of ocean species and this research informs the factors that underly these relationships.</p> <p>The advent of DNA sequencing, imaging, and other molecular approaches have revealed that many key species in the ocean are a 'holobiome', and their fate is entwined with the microbes they host. Yet, this discovery of microbial taxa in nature far outpaces our understanding of microbial function. <em>Nereocystis luetkeana</em>, or bull kelp, and the bacteria the investigators have isolated from the kelp surface, present an opportunity to quantify host-microbe interactions, including how stressors of host health, such as ocean warming, alter these interactions. Experiments tracing stable nitrogen isotopes and manipulations with hosts and bacterial isolates are used to investigate possible exchanges and the currencies underlying interactions. Metabolomic, proteomic, and genomic analyses are used to quantify host-microbe interactions and linkage between taxa and their functions. Key microbial metabolisms being investigated include nutrient provisioning, vitamin synthesis, and the response to reactive oxygen species, among others. The demonstrated alteration of host-microbe interactions in the ocean when hosts are stressed suggest the findings of this study have application to understanding the factors that promote persistence of eukaryote-prokaryote partnerships.</p> <p>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.</p> kelp and their microbiome largerWorkCitation project eng; USA oceans -124.73382 -122.39833 47.166522 47.166522 2019-07-02 2022-08-14 Northeast Pacific Ocean, coastal Washington state 0 BCO-DMO catalogue of parameters from Nereocystis luetkeana geographic patterns in physiology and microbiome from samples collected from 2019 to 2022 at nine sites spanning more than 200 kilometers in Washington state Biological and Chemical Oceanography Data Management Office (BCO-DMO) Unavailable 508-289-2009 WHOI MS#36 Woods Hole MA 02543 USA info@bco-dmo.org http://www.bco-dmo.org Monday - Friday 8:00am - 5:00pm For questions regarding this resource, please contact BCO-DMO via the email address provided. pointOfContact http://lod.bco-dmo.org/id/dataset-parameter/1001312.rdf Name: year Units: unitless Description: <p>Year</p> http://lod.bco-dmo.org/id/dataset-parameter/1001313.rdf Name: date Units: Unitless Description: <p>Date</p> http://lod.bco-dmo.org/id/dataset-parameter/1001314.rdf Name: month Units: unitless Description: <p>month</p> http://lod.bco-dmo.org/id/dataset-parameter/1001315.rdf Name: locale Units: unitless Description: <p>within coastal Washington state; see Methods</p> http://lod.bco-dmo.org/id/dataset-parameter/1001316.rdf Name: region Units: unitless Description: <p>locale divided into 3 regions in coastal Washington state</p> http://lod.bco-dmo.org/id/dataset-parameter/1001317.rdf Name: latitude Units: decimal degrees Description: <p>Latitude</p> http://lod.bco-dmo.org/id/dataset-parameter/1001319.rdf Name: longitude Units: decimal degrees Description: <p>Longitude</p> http://lod.bco-dmo.org/id/dataset-parameter/1001321.rdf Name: replicate Units: unitless Description: <p>per site per year</p> http://lod.bco-dmo.org/id/dataset-parameter/1001322.rdf Name: wetmass_g Units: grams Description: <p>wetmass of Nereocystis tissue used in estimating carbon fixation, reported in grams</p> http://lod.bco-dmo.org/id/dataset-parameter/1001323.rdf Name: drymass_g Units: grams Description: <p>drymass of Nereocystis tissue used in estimating carbon fixation, reported in grams</p> http://lod.bco-dmo.org/id/dataset-parameter/1001324.rdf Name: mgCfixed_gdrymass_hr Units: milligrams per gram drymass per hour Description: <p>the mg of Carbon fixed per g drymass of Nereocystis per hour</p> http://lod.bco-dmo.org/id/dataset-parameter/1001325.rdf Name: DOCmgl_release_gdrymass_hr_corr01 Units: milligrams per gram drymass per hour Description: <p>the mg of dissolved organic Carbon released per g drymass of Nereocystis per hour, with 0.01 added to all values to allow analyses of log values for all and to avoid dividing by zero (see below)</p> http://lod.bco-dmo.org/id/dataset-parameter/1001326.rdf Name: DOC_um_hr_drymass Units: micromolar (uM) Description: <p>the uM of Carbon dissolved organic Carbon released per g drymass of Nereocystis per hour</p> http://lod.bco-dmo.org/id/dataset-parameter/1001327.rdf Name: to_po4 Units: micromolar (uM) Description: <p>the initial P04 concentration in uM</p> http://lod.bco-dmo.org/id/dataset-parameter/1001328.rdf Name: to_si Units: micromolar (uM) Description: <p>the initial SiO4 concentration in uM</p> http://lod.bco-dmo.org/id/dataset-parameter/1001329.rdf Name: to_no3 Units: micromolar (uM) Description: <p>the initial NO3 concentration in uM</p> http://lod.bco-dmo.org/id/dataset-parameter/1001330.rdf Name: to_no2 Units: micromolar (uM) Description: <p>the initial NO2 concentration in uM</p> http://lod.bco-dmo.org/id/dataset-parameter/1001331.rdf Name: to_nh4 Units: micromolar (uM) Description: <p>the initial NH4 concentration in uM</p> http://lod.bco-dmo.org/id/dataset-parameter/1001332.rdf Name: to_DIN Units: micromolar (uM) Description: <p>the initial dissolved inorganic nitrogen concentration in uM</p> http://lod.bco-dmo.org/id/dataset-parameter/1001333.rdf Name: uM_DOC_to Units: micromolar (uM) Description: <p>the initial dissolved organic carbon concentration in uM</p> http://lod.bco-dmo.org/id/dataset-parameter/1001334.rdf Name: tf_po4 Units: micromolar (uM) Description: <p>the final P04 concentration in uM</p> http://lod.bco-dmo.org/id/dataset-parameter/1001335.rdf Name: tf_si Units: micromolar (uM) Description: <p>the final SiO4 concentration in uM</p> http://lod.bco-dmo.org/id/dataset-parameter/1001336.rdf Name: tf_no3 Units: micromolar (uM) Description: <p>tf_no3 - the final NO3 concentration in uM</p> http://lod.bco-dmo.org/id/dataset-parameter/1001337.rdf Name: tf_no2 Units: micromolar (uM) Description: <p>tf_no2 - the final NO2 concentration in uM</p> http://lod.bco-dmo.org/id/dataset-parameter/1001338.rdf Name: tf_nh4 Units: micromolar (uM) Description: <p>tf_nh4 - the final NH4 concentration in uM</p> http://lod.bco-dmo.org/id/dataset-parameter/1001339.rdf Name: tf_DIN Units: micromolar (uM) Description: <p>tf_DIN - the final dissolved inorganic nitrogen concentration in uM</p> http://lod.bco-dmo.org/id/dataset-parameter/1001340.rdf Name: no3_uptake_h_gdm Units: uM change per gram drymass per hour Description: <p>no3_uptake_h_gdm - the uM change in NO3 per hour per gram drymass of Nereocystis</p> http://lod.bco-dmo.org/id/dataset-parameter/1001341.rdf Name: bulb_diam Units: millimeters (mm) Description: <p>bulb_diam - widest part of bulb, in mm</p> http://lod.bco-dmo.org/id/dataset-parameter/1001342.rdf Name: blade_length Units: centimeters (cm) Description: <p>blade_length - blade length used in assay, in cm</p> http://lod.bco-dmo.org/id/dataset-parameter/1001343.rdf Name: repro Units: unitless Description: <p>indication of whether kelp is reproductive (R) or not (NR)</p> http://lod.bco-dmo.org/id/dataset-parameter/1001344.rdf Name: deln Units: per mil Description: <p>the delta 15N, stable isotope ratio of Nitrogen, in Nereocystis tissue</p> http://lod.bco-dmo.org/id/dataset-parameter/1001345.rdf Name: delc Units: per mil Description: <p>delc - the delta 13C, stable isotope ratio of Carbon, in Nereocystis tissue</p> http://lod.bco-dmo.org/id/dataset-parameter/1001346.rdf Name: pctn Units: percent Description: <p>pctn - the percent of tissue nitrogen (as dry mass) in Nereocystis tissue</p> http://lod.bco-dmo.org/id/dataset-parameter/1001347.rdf Name: pctc Units: percent Description: <p>pctc - the percent of tissue carbon (as dry mass) in Nereocystis tissue</p> http://lod.bco-dmo.org/id/dataset-parameter/1001348.rdf Name: c_n Units: ratio Description: <p>c_n - the ratio of tissue carbon to tissue nitrogen (pctc/pctn)</p> http://lod.bco-dmo.org/id/dataset-parameter/1001349.rdf Name: temperature Units: degrees Celsius Description: <p>temperature - in deg C</p> http://lod.bco-dmo.org/id/dataset-parameter/1001350.rdf Name: salinity Units: ppt Description: <p>salinity - in ppt</p> http://lod.bco-dmo.org/id/dataset-parameter/1001351.rdf Name: ratioCfixtoDOCrel Units: ratio Description: <p>ratioCfixtoDOCrel - the ratio of inorganic carbon fixed to dissolved organic carbon released (mcCfixed_gdrymasshr/DOCmgl_release_gdrymass_hr_corr01)</p> GB/NERC/BODC > British Oceanographic Data Centre, Natural Environment Research Council, United Kingdom Biological and Chemical Oceanography Data Management Office (BCO-DMO) Unavailable 508-289-2009 WHOI MS#36 Woods Hole MA 02543 USA info@bco-dmo.org http://www.bco-dmo.org Monday - Friday 8:00am - 5:00pm For questions regarding this resource, please contact BCO-DMO via the email address provided. pointOfContact https://osprey.bco-dmo.org/dataset/1000920/data/download download onLine dataset &lt;p&gt;These are data on kelp traits, seawater features and 16S rRNA amplicon sequencing. All kelp measurements were made in situ, often via kayak or at the shore using a measuring tape and calipers.&lt;/p&gt; &lt;p&gt;Kelp tissue was collected for elemental analysis by excising a 2 x 2 centimeter (cm) piece of tissue in the meristematic region. Tissue was ground to a fine powder in a GenoGrinder Spex (Metuchen, NJ), weighed in aliquots of 1.2 to 1.5 milligrams (mg) and packed into 3.5 × 5 millimeter (mm) aluminium tins (Costech, Valencia, CA). Packed tins were analysed on an elemental analyser isotope ratio mass spectrometer at Northwestern University Stable Isotope Biogeochemistry Laboratory (NUSIBL).&lt;/p&gt; &lt;p&gt;Carbon fixation was quantified using a section of the youngest, basal frond tissue extending 24 to 30 cm from the bulb. It was weighed (wet mass in grams (g)) with a Pesola scale and placed in a 1 liter (L) Nalgene container; the change in oxygen was measured for 1 hour with a Pyro Science contactless fibre-optic sensors (Oxygen Sensor Spots OXSP5) and an optical oxygen and temperature meter (FireStingO2 FSO2-4), with the sensor spots affixed inside each 1 L chamber.&lt;/p&gt; &lt;p&gt;DOC release and nutrient changes were quantified from seawater filtered through a GF/F filter and immediately frozen for analysis at the University of Washington Marine Chemistry Laboratory (methods from UNESCO), with DOC samples frozen in 40 milliliter (mL) glass vials with Teflon caps (Shimadzu, VOA) and other nutrients in acid-washed 60 mL high density polyethylene (HDPE) Nalgene bottles.&lt;/p&gt; &lt;p&gt;Using pulse amplitude modulated (PAM) fluorometry &lt;em&gt;in situ&lt;/em&gt; (Diving Pam, Walz, Germany) we estimated fluorescence over a range of irradiances. PAM is a non-invasive, &lt;em&gt;in situ&lt;/em&gt; method that quantifies Photosystem II fluorescence parameters across different light levels. Tissue was dark-adapted for 20 minutes and then rapid light curves were estimated with nine PAR levels from 0 to 1200. We estimated the maximum electron transport rate (ETR&lt;sub&gt;max&lt;/sub&gt;) and the photosynthetic efficiency at low light, both as the initial linear slope of ETR to irradiance (&lt;em&gt;α&lt;/em&gt;) and as the quantum yield of photosystem II (Yield) on nine individual &lt;em&gt;Nereocystis&lt;/em&gt; at both Tatoosh Island and Squaxin Island, the populations that span the greatest range of environmental conditions. Tatoosh Island was assayed on 9 and 20 June 2019 and Squaxin Island on 2 July 2019. At both sites, we selected individuals at least 1 meter (m) apart at low tide.&lt;/p&gt; &lt;p&gt;The salinity and seawater temperatures were assessed with a Castaway-CTD (Sontek) from a boat or kayak at all sites except Tatoosh Island where instrumentation is moored (Hach DS5).&lt;/p&gt; &lt;p&gt;Microbial density on individual kelp blades at either end of the geographic distribution, Tatoosh Island versus Squaxin Island, differed using 4,6-diamidino-2-phenylindole (DAPI) fluorescent staining of bacterial cells. We quantified bacterial cells from a section of the blade at approximately 20 cm distal from where the blade articulates with the bulb. We sampled a 3−5 mm slice from 10 individuals at each site (Tatoosh on 4 August 2019, Squaxin on 2 July 2019), preserving each slice immediately in Formalin, transferring to 50 : 50 EtOH : phosphate-buffered saline (PBS) after 1 hour, then freezing. In the laboratory, each piece was again sliced with a razor blade to approximately 0.5 mm, placed on a glass slide, and a solution of 1 microgram (µg) DAPI : 1 mL PBS was dropped on the slide-mounted slice. The slide was kept in dark for 20 minutes, chilled and rinsed with PBS prior to visualizing at 100× with an Olympus BX50 fluorescence microscope with a DAPI filter. We photographed 10 fields of view, selected haphazardly, for each individual slice, resulting in 100 images at each Tatoosh and Squaxin. In samples where bacteria were sparse or non-existent, we repeatedly adjusted the fine focus to verify no bacteria were present. We quantified the bacteria in ImageJ, enumerating the cells in the blue channel, adjusting the background and thresholds identically for all 200 images to eliminate autofluorescence by kelp cells. We calculated bacterial cell density as a percentage of the total imaged area.&lt;/p&gt; &lt;p&gt;Individual kelp was sampled for microbes by rubbing a cotton swab for 20−30 seconds over the mid-blade region. The swab was placed in a 2 mL Eppendorf tube, immediately chilled and transferred to a freezer within 4−6 hours. DNA from the swabs was extracted with a Qiagen DNeasy PowerSoil Kit (Qiagen). DNA was amplified, sequenced and amplicon sequence variants (ASVs) were identified by the Duchossois Family Institute Microbial Metagenomics Facility (DFIMMF) at The University of Chicago. The V4–V5 region within the 16S ribosomal RNA (rRNA) gene was amplified using universal bacterial primers and polymerase chain reaction (PCR) conditions described in Younker, et al. (2024). Approximately 412 bp region amplicons were then purified using a spin column-based method (Minelute, Qiagen), quantified and dual index adapters were ligated. Sequences were generated from the Illumina MiSeq platform using the QIASeq 1-step amplicon kit (Qiagen) for generating libraries and using 2 × 250 paired end reads with 5000 to 10,000 reads per sample. The default pipeline for processing MiSeq 16S rRNA reads was dada2 (v. 1.18.0) with minor modifications in R (v. 4.0.3). Reads were first trimmed at 190 bp for both forward and reverse reads to remove low-quality nucleotides, and chimaeras were detected and removed using the default consensus method in the dada2 pipeline. Then, ASVs with length between 320 and 365 bp were retained. Taxonomy of the resultant ASVs were assigned to the genus level using the RDP classifier (v. 2.13) with a minimum bootstrap confidence score of 80. Species-level classification used blastn (v. 2.13.0) and the refseq_rna database. We analysed ASVs with R, phyloseq and microViz (R version 2023.06.2+561). Chloroplast DNA that was not classified as Cyanobacteria were generally diatoms (Bacillarophyta) and were filtered out, as well as any other chloroplast sequence that did not match to the class Cyanobacteria. Sequences of corn (Zea, in Plantae), in low numbers at some Puget Sound sites, were also removed.&lt;/p&gt; &lt;p&gt;All methods are described in the Pfister, et al. (2025) paper.&lt;/p&gt; Specified by the Principal Investigator(s) &lt;p&gt;Basic statistical analysis was done with R, version 2023.06.2+561.&lt;/p&gt; &lt;p&gt;Packages used within R included phyloseq, microviz, ggplot, vegan, nlme, tidyverse&lt;/p&gt; Specified by the Principal Investigator(s) - Loaded data from original file &quot;Pfister_NereocystisGeography_RoySocOpen2025_BCODMO.csv&quot; into the BCO-DMO system, treating &quot;NA&quot; as a missing data value (missing data values are empty/blank in the final CSV file). - Converted date column from %m/%d/%y format to %Y-%m-%d format. - Saved the final file as &quot;1000920_v1_nereocystis_geography.csv&quot;. Specified by BCO-DMO Data Managers asNeeded 7.x-1.1 Biological and Chemical Oceanography Data Management Office (BCO-DMO) Unavailable 508-289-2009 WHOI MS#36 Woods Hole MA 02543 USA info@bco-dmo.org http://www.bco-dmo.org Monday - Friday 8:00am - 5:00pm For questions regarding this resource, please contact BCO-DMO via the email address provided. pointOfContact Illumina MiSeq Illumina MiSeq PI Supplied Instrument Name: Illumina MiSeq PI Supplied Instrument Description:Sequences were generated from the Illumina MiSeq platform. Instrument Name: Automated DNA Sequencer Instrument Short Name:Automated Sequencer Instrument Description: A DNA sequencer is an instrument that determines the order of deoxynucleotides in deoxyribonucleic acid sequences. calipers calipers PI Supplied Instrument Name: calipers PI Supplied Instrument Description:All kelp measurements were made in situ, often via kayak or at the shore using a measuring tape and calipers. Instrument Name: calipers Instrument Short Name: Instrument Description: A caliper (or "pair of calipers") is a device used to measure the distance between two opposite sides of an object. Many types of calipers permit reading out a measurement on a ruled scale, a dial, or a digital display. Qiagen DNeasy PowerSoil Kit (Qiagen) Qiagen DNeasy PowerSoil Kit (Qiagen) PI Supplied Instrument Name: Qiagen DNeasy PowerSoil Kit (Qiagen) PI Supplied Instrument Description:DNA from the swabs was extracted with a Qiagen DNeasy PowerSoil Kit (Qiagen). Instrument Name: DNA Analysis Kit Instrument Short Name: Instrument Description: A laboratory kit containing reagents and materials used to extract, purify, detect, measure, or otherwise evaluate DNA from a sample. Olympus BX50 fluorescence microscope Olympus BX50 fluorescence microscope PI Supplied Instrument Name: Olympus BX50 fluorescence microscope PI Supplied Instrument Description:Slides were visualized at 100× with an Olympus BX50 fluorescence microscope with a DAPI filter. Instrument Name: Fluorescence Microscope Instrument Short Name: Instrument Description: Instruments that generate enlarged images of samples using the phenomena of fluorescence and phosphorescence instead of, or in addition to, reflection and absorption of visible light. Includes conventional and inverted instruments. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB06/ pulse amplitude modulated (PAM) fluorometry in situ (Diving Pam, Walz, Germany) pulse amplitude modulated (PAM) fluorometry in situ (Diving Pam, Walz, Germany) PI Supplied Instrument Name: pulse amplitude modulated (PAM) fluorometry in situ (Diving Pam, Walz, Germany) PI Supplied Instrument Description:Using pulse amplitude modulated (PAM) fluorometry in situ (Diving Pam, Walz, Germany) we estimated fluorescence over a range of irradiances. PAM is a non-invasive, in situ method that quantifies Photosystem II fluorescence parameters across different light levels. Instrument Name: Fluorometer Instrument Short Name:Fluorometer Instrument Description: A fluorometer or fluorimeter is a device used to measure parameters of fluorescence: its intensity and wavelength distribution of emission spectrum after excitation by a certain spectrum of light. The instrument is designed to measure the amount of stimulated electromagnetic radiation produced by pulses of electromagnetic radiation emitted into a water sample or in situ. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/113/ GenoGrinder Spex GenoGrinder Spex PI Supplied Instrument Name: GenoGrinder Spex PI Supplied Instrument Description:Kelp tissue was ground to a fine powder in a GenoGrinder Spex (Metuchen, NJ). Instrument Name: Homogenizer Instrument Short Name:Homogenizer Instrument Description: A homogenizer is a piece of laboratory equipment used for the homogenization of various types of material, such as tissue, plant, food, soil, and many others. elemental analyser isotope ratio mass spectrometer elemental analyser isotope ratio mass spectrometer PI Supplied Instrument Name: elemental analyser isotope ratio mass spectrometer PI Supplied Instrument Description:Packed tins were analysed on an elemental analyser isotope ratio mass spectrometer at Northwestern University Stable Isotope Biogeochemistry Laboratory (NUSIBL). Instrument Name: Isotope-ratio Mass Spectrometer Instrument Short Name:IR Mass Spec; IRMS Instrument Description: The Isotope-ratio Mass Spectrometer is a particular type of mass spectrometer used to measure the relative abundance of isotopes in a given sample (e.g. VG Prism II Isotope Ratio Mass-Spectrometer). Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB16/ measuring tape measuring tape PI Supplied Instrument Name: measuring tape PI Supplied Instrument Description:All kelp measurements were made in situ, often via kayak or at the shore using a measuring tape and calipers. Instrument Name: Measuring Tape Instrument Short Name: Instrument Description: A tape measure or measuring tape is a flexible ruler. It consists of a ribbon of cloth, plastic, fibre glass, or metal strip with linear-measurement markings. It is a common tool for measuring distance or length. optical oxygen and temperature meter (FireStingO2 FSO2-4) optical oxygen and temperature meter (FireStingO2 FSO2-4) PI Supplied Instrument Name: optical oxygen and temperature meter (FireStingO2 FSO2-4) PI Supplied Instrument Description:The change in oxygen was measured for 1 hour with a Pyro Science contactless fibre-optic sensors (Oxygen Sensor Spots OXSP5) and an optical oxygen and temperature meter (FireStingO2 FSO2-4), with the sensor spots affixed inside each 1 L chamber. Instrument Name: Oxygen Sensor Instrument Short Name:Dissolved Oxygen Sensor Instrument Description: An electronic device that measures the proportion of oxygen (O2) in the gas or liquid being analyzed Oxygen Sensor Spots (OXSP5) Oxygen Sensor Spots (OXSP5) PI Supplied Instrument Name: Oxygen Sensor Spots (OXSP5) PI Supplied Instrument Description:The change in oxygen was measured for 1 hour with a Pyro Science contactless fibre-optic sensors (Oxygen Sensor Spots OXSP5) and an optical oxygen and temperature meter (FireStingO2 FSO2-4), with the sensor spots affixed inside each 1 L chamber. Instrument Name: Oxygen Sensor Spot Instrument Short Name:Oxygen Sensor Patch Instrument Description: Oxygen sensor spots allow oxygen measurements in closed sample containers with contactless read-out through a transparent window (glass, acryl glass) with special adapters and optical fibers.  These patches often have a self-adhesive option.   Pesola scale Pesola scale PI Supplied Instrument Name: Pesola scale PI Supplied Instrument Description:The youngest basal frond tissue extending 24 to 30 cm from the bulb was weighed with a Pesola scale. Instrument Name: scale or balance Instrument Short Name: Instrument Description: Devices that determine the mass or weight of a sample. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB13/ Castaway-CTD (Sontek) Castaway-CTD (Sontek) PI Supplied Instrument Name: Castaway-CTD (Sontek) PI Supplied Instrument Description:The salinity and seawater temperatures were assessed with a Castaway-CTD (Sontek) from a boat or kayak at all sites except Tatoosh Island where instrumentation is moored (Hach DS5). Instrument Name: SonTek CastAway-CTD Instrument Short Name:CastAway-CTD Instrument Description: The Sontek CastAway-CTD (manufactured by Xylem) is a handheld castable instrument that provides instantaneous profiles of temperature, salinity, and sound speed. Each cast is referenced with both time and location using its built-in GPS receiver. The CastAway software displays profiles of the casts in addition to mapping the locations of the data collection points. The CastAway-CTD has a 5 Hz response and sampling rate, accurate to 0.1 (PSS-78), 0.05° Celsius. Conductivity range is 0 to 100,000 µS/cm. Temperature range is -5° to 45° Celsius. Pressure range is 0 to 100 decibars. Further specs and information can be found on the manufacturer's website: https://www.xylem.com/en-us/brands/wtw/wtw-products/castaway-ctd/ polymerase chain reaction (PCR) polymerase chain reaction (PCR) PI Supplied Instrument Name: polymerase chain reaction (PCR) PI Supplied Instrument Description:The V4–V5 region within the 16S ribosomal RNA (rRNA) gene was amplified using universal bacterial primers and polymerase chain reaction (PCR) conditions. Instrument Name: Thermal Cycler Instrument Short Name:Thermal Cycler Instrument Description: A thermal cycler or "thermocycler" is a general term for a type of laboratory apparatus, commonly used for performing polymerase chain reaction (PCR), that is capable of repeatedly altering and maintaining specific temperatures for defined periods of time. The device has a thermal block with holes where tubes with the PCR reaction mixtures can be inserted. The cycler then raises and lowers the temperature of the block in discrete, pre-programmed steps. They can also be used to facilitate other temperature-sensitive reactions, including restriction enzyme digestion or rapid diagnostics. (adapted from http://serc.carleton.edu/microbelife/research_methods/genomics/pcr.html) Hach DS5 Hach DS5 PI Supplied Instrument Name: Hach DS5 PI Supplied Instrument Description:The salinity and seawater temperatures were assessed with a Castaway-CTD (Sontek) from a boat or kayak at all sites except Tatoosh Island where instrumentation is moored (Hach DS5). Instrument Name: Water Quality Multiprobe Instrument Short Name:Water Quality Multiprobe Instrument Description: An instrument which measures multiple water quality parameters based on the sensor configuration.