http://lod.bco-dmo.org/id/dataset/906469 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 2023-08-17 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) Carbon and nitrogen data from kelp determined during seasonal global change experiments examining the effects of seasonal variation in light availability and nutrients on the response of three high-latitude kelp species 2023-08-18 publication 2023-08-18 revision Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA) 2023-08-28 publication https://doi.org/10.26008/1912/bco-dmo.906469.1 Lauren E. Bell University of California-Santa Cruz principalInvestigator Kristy J. Kroeker University of California-Santa Cruz 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: Bell, L. E., Kroeker, K. J. (2023) Carbon and nitrogen data from kelp determined during seasonal global change experiments examining the effects of seasonal variation in light availability and nutrients on the response of three high-latitude kelp species. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 1) Version Date 2023-08-18 [if applicable, indicate subset used]. doi:10.26008/1912/bco-dmo.906469.1 [access date] Carbon and Nitrogen Dataset Description: Methods and Sampling: &lt;p&gt;To tease apart the effects of seasonal variation in light availability and nutrients on the response of high-latitude kelp species to pH and temperature, the investigators conducted two separate studies: a &quot;winter&quot; experiment from February 12 to March 18, 2020 (35 days), and a &quot;summer&quot; experiment from August 15 to September 16, 2020 (32 days). In the experimental design, analysis, and reporting, the investigators endeavored to follow best practices for OA research with macroalgae (Cornwall et al., 2012; Cornwall &amp;amp; Hurd, 2016). Both experiments took place at the Sitka Sound Science Center in a flow-through seawater system drawing source water from 20 meters (m) depth (MLLW) in Sitka Sound, Alaska. Incoming seawater was filtered to 20 micrometers (μm) and routed through a UV filter (Smart UV®, Pentair) before diverging into two temperature-controlled (TITAN® heat pump and Optima compact heaters, AquaLogic) recirculating tanks representing treatments for &quot;current&quot; or control temperatures (7° Celsius (C) in winter; 14°C in summer) and &quot;future&quot; ocean warming (OW) projections (11°C in winter; 18°C in summer) (IPCC, 2018) by season. From here, temperature-regulated seawater was pumped into eight header tanks where pH was maintained at setpoint levels for control conditions (pHT 7.6 in winter; pHT 7.9 in summer) and &quot;future&quot; ocean acidification (OA) projections (pHT 7.2 in winter; pHT 7.5 in summer) (Mathis et al., 2015) through a relay system (N = 2 header tanks per pH/temperature treatment). In both seasonal experiments, achievable pHT setpoints for control treatments were constrained by the ambient pH of incoming seawater and were, therefore, lower than the typical seasonal &lt;em&gt;in situ&lt;/em&gt; pHTminima observed on local rocky reefs by ~0.1 - 0.2 pH units (Kroeker et al., 2021). That said, the lower-than-average pH values of the control treatments did still fall within the observed pHs captured across all years of in situ environmental data. The investigators chose to maintain the projected end-of-century pH offset for this region (~0.4 pH units) to define the OA treatment setpoints relative to achievable control pH levels. A DuraFET sensor (Honeywell) in each header tank communicated real-time pH measurements to a controller (UDA 2152, Honeywell) that regulated injection of pre-equilibrated low pH seawater through solenoid valves into the headers to maintain pH at treatment set points. The low pH (~6) seawater was produced by bubbling pure CO2 gas into two tanks of seawater flowing from each temperature-controlled tank. Once in each header tank, the CO2 and temperature-equilibrated seawater was continuously mixed before delivery to 24 experimental aquaria (N = 3 aquaria per header) at an average flow-through rate of 2-2.5 liters per minute per aquaria (L min-1 aquaria-1). The &quot;Header pH and Temperature&quot; Supplemental File (2020_kelpGCexps_headerdata.csv) contains a summary of the calibrated pH and temperature data recorded by the Durafet sensors in each header during the experiments.&lt;/p&gt; &lt;p&gt;Seawater nutrient concentrations were not manipulated and thus reflected what was delivered through source water inflow to the system during each experiment. Terrestrial outflow from heavy precipitation over Southeast Alaska’s temperate rainforests and wind stress dynamics in the Gulf of Alaska control nutrient supply onto the Northeast Pacific shelves (Hermann et al., 2009; Hood &amp;amp; Scott, 2008; Ladd &amp;amp; Cheng, 2016; Stabeno et al., 2016). The complexities of how climate change may impact these drivers in tandem with altered phytoplankton productivity (Ji et al., 2010) means that there is little consensus on how seasonal nutrient supply into Sitka Sound may change. Therefore, the investigators chose to assume that nutrient availability, like seasonal light availability, would not differ significantly in this region in the future. All aquaria were fitted with a full-spectrum light (Aqua Illumination) that provided seasonally relevant regimes of photosynthetically active radiation spectra and photoperiod within the aquaria based on observations during overcast days in Sitka Sound (Bell et al., 2022). The entire experimental system was shielded from external light sources, and aquaria positions were randomized by treatment and location in the laboratory to minimize spatial variation among the random factors &lt;em&gt;aquaria&lt;/em&gt; and &lt;em&gt;header&lt;/em&gt;. The &quot;Nutrient Concentrations with Experimental Aquaria&quot; Supplemental File (2020_kelpGCexps_nutrients.csv) contains the data on nutrient concentrations within experimental aquaria.&lt;/p&gt; &lt;p&gt;At the beginning, middle, and end of each experiment, discrete water samples were collected for the determination of pHT, TA, and nutrient concentrations in each aquarium and header tank. Water samples were collected without aeration and poisoned with saturated HgCl2 (0.025%) in glass bottles within 20 minutes. Airtight samples were transported to the University of California Santa Cruz (UCSC) for analysis within 9 months of collection. pH was measured spectrophotometrically (Shimadzu, UV-1800) using m-cresol purple following best practices (Dickson et al., 2007). Total alkalinity (TA) was measured using open cell titration (Metrohm, 905 Titrandro) and corrected against certified reference materials of CO2 in seawater (Dickson laboratory, Scripps Institute of Oceanography). Water chemistry samples from each tank had a mean standard error of 0.0013 pH units and 0.87 micromoles per kilogram seawater (μmol kg-1 SW-1) among sample triplicates. To calculate in situ pH on the total hydrogen ion concentration scale (pHT; mol kg-1 SW-1)(Dickson, 1993), the investigators used their laboratory measurements of spectrophotometric pH and TA, measurements of temperature and salinity recorded with a handheld meter (YSI) concurrently with discrete water sample collection, and stoichiometric dissociation constants (Dickson &amp;amp; Millero, 1987; Mehrbach et al., 1973) as inputs to the program CO2SYS (Lewis &amp;amp; Wallace, 1998; Pierrot et al., 2006). Corrections were applied to the continuous time series of pH values recorded by durafets in each header during each experiment by calculating an average offset from pHT values calculated from discrete samples.&lt;/p&gt; &lt;p&gt;Kelp used in both winter and summer experiments came from 4.5-7.5 m depth at Talon Island (57.073 N, 135.414 W), Sitka Sound. These experimental &quot;individuals&quot; were collected as whole thalli (&lt;em&gt;Neoagarum fimbriatum&lt;/em&gt; and &lt;em&gt;Hedophyllum nigripes&lt;/em&gt;), or as single blades with their attached pneumatocysts that were cut from young sporophytes at approximately 1 m above their holdfasts (&lt;em&gt;Macrocystis pyrifera&lt;/em&gt;). During transport to the laboratory and prior to the start of the experiments (less than 2 days), all algae was held continuously in ambient flow-through seawater (winter experiment: ~6°C, pHT 7.8; summer experiment: ~13.5°C, pHT 8.0). Individuals were removed briefly only to clean off epiphytes and to record initial morphometrics (maximum blade length, total wet mass) after trimming all blades to 10 centimeters (cm) total length. The investigators took pictures of each trimmed blade to estimate total surface area using ImageJ (NIH v1.8.0).&lt;/p&gt; &lt;p&gt;In both the winter and summer experiments, 3 individuals of each kelp species were randomly assigned to each experimental aquaria (N = 18 individuals per species per treatment). The investigators affixed individuals upright in aquaria by placing their stipes or pneumatocysts through three-strand line suspended over the open ends of 5 cm tall PVC stands. After all seaweeds were processed for initial morphometrics, pH and temperature were gradually changed in treatment tanks stepwise over the course of 3 days to reach final setpoints. During the experiment, kelps were visually checked daily for necrosis and were lightly brushed biweekly during aquaria cleaning to remove diatoms.&lt;/p&gt; &lt;p&gt;At the end of each experiment, individuals were measured and photographed for final morphometrics. Due to the difficulty in capturing three-dimensional tissue growth and the error inherent in wet mass measurements, kelp growth rates were estimated using three different metrics: wet mass in grams (g), maximum blade length in centimeters (cm), and total blade surface area in square centimeters (cm²). The initial (Ginitial) and final (Gfinal) measurements of each metric were used to calculate three relative growth rates (RGR; percent per day (% d-1)) for each individual using Equation 1 (see the attached Supplemental File), where Δt (days (d)) represents the total number of days elapsed between the beginning and end of the experiment. Relative growth rates were used for subsequent statistical analyses of experimental results. Absolute blade length extension rates were used to compare experimental growth to &lt;em&gt;in situ&lt;/em&gt; kelp growth measurements (Bell &amp;amp; Kroeker, 2022).&lt;/p&gt; &lt;p&gt;From each individual, the investigators excised new blade tissue grown during the experiment adjacent to the intercalary meristem and pooled this tissue for all species replicates in each aquarium. A portion of this tissue was frozen at -20°C for use in feeding assays. The other portion of this tissue was dried at 60°C for &amp;gt;24 hours and analyzed for nitrogen (N) content (% dry mass) and δ13C values by the UCSC Stable Isotope Laboratory using a CE Instruments NC2500 elemental analyzer coupled to a Thermo Scientific DELTAplus XP isotope ratio mass spectrometer via a Thermo-Scientific Conflo III (routine measurement error ≤ 1.0 %C and ≤ 0.2 %N). The investigators also analyzed blade tissue from non-experimental kelp individuals collected at Talon Islands in each season (&quot;field controls&quot;; N=6 species-1 season-1) for elemental and isotopic analysis.&lt;/p&gt; &lt;p&gt;To compare &lt;em&gt;in situ&lt;/em&gt; nutrient and light data with aquaria conditions during the experiment, environmental data was collected at the Talon Island experimental collection site. Benthic seawater was collected for the determination of nutrient concentrations in February and August 2020 (N=3 samples-1 season-1). Seawater for nutrient samples was immediately filtered through a 0.2 µm filter and frozen until analysis for dissolved inorganic nitrogen content as NOx (NO3 + NO2) and ammonium (NH4+) on a Lachat QuikChem 8000 Flow Injection Analyzer at the University of California Santa Cruz Marine Analytical Laboratory (detection limits: &amp;lt; 0.28 µM NOx, &amp;lt; 2.40 µM NH4; average run measurement error &amp;lt; 0.1 µM NOx &amp;lt; 0.8 µM NH4). A Diving-PAM-II (Heinz Wlz GmbH) MINI-SPEC was used to haphazardly record the photosynthetic photon flux density (PPFD; micromoles per square meter per second (µmol m-2 s-1) reaching the benthos at more than 10 locations along the ~5 m depth contour on two clear days in winter (February 28) and summer (September 19).&lt;/p&gt; &lt;p&gt;Tissue from &lt;em&gt;H. nigripes&lt;/em&gt; and &lt;em&gt;N. fimbriatum&lt;/em&gt; individuals grown in the laboratory was used to investigate whether future ocean conditions affect the palatability of these understory kelp species in either season. In April 2021, methods used by Hay et al. (1994) were modified to create &quot;gels&quot; of homogenized kelp tissue suspended in agar and enmeshed in squares of window screen. Each 30 cm² gel was formed from 0.1547 ± 0.0004 g (mean ± SE) of freeze-dried (FreeZone, Labconco) &lt;em&gt;H. nigripes&lt;/em&gt; or &lt;em&gt;N. fimbriatum&lt;/em&gt; tissue growth in either the control treatment or the combination OW and OA treatment from each seasonal experiment. The total number of gels used for the feeding assays was limited by the available kelp tissue grown during each experiment, and was consequently lower for gels made from tissue grown in the winter experiment (&lt;em&gt;H. nigripes&lt;/em&gt;: N = 11 gels per treatment, &lt;em&gt;N. fimbriatum&lt;/em&gt;: N = 12 gels per treatment) versus the summer experiment (&lt;em&gt;H. nigripes&lt;/em&gt;: N = 24 gels per treatment, &lt;em&gt;N. fimbriatum&lt;/em&gt;: N = 23 gels per treatment). Palatability assays were run by feeding these seaweed gels to the common kelp forest grazer, &lt;em&gt;Strongylocentrotus droebachiensis&lt;/em&gt; (green urchin). Urchins with a test diameter of 24 ± 3 millimeters (mm) were collected from the intertidal, starved for 48 hours, and then placed in a flow-through chamber with a single gel in ambient seawater conditions (~7 °C, ~8.0 pH) for 48 hours. Photographs were taken of each gel before and after the assay and the relative consumption of seaweeds grown under different treatments was determined using Image J (NIH v1.8.0).&lt;/p&gt; Funding provided by NSF Division of Ocean Sciences (NSF OCE) Award Number: OCE-1752600 Award URL: https://www.nsf.gov/awardsearch/show-award?AWD_ID=1752600 Funding provided by David and Lucile Packard Foundation (Packard) Award Number: Packard - Kelp Ecosystem Dynamics Funding provided by North Pacific Research Board (NPBR) Award Number: Graduate Student Research Award 1748-02 completed Lauren E. Bell University of California-Santa Cruz 907-738-8007 312 Cascade St. Sitka AK 99835 USA lbell@sitkascience.org pointOfContact Kristy J. Kroeker University of California-Santa Cruz 831-566-8253 100 Shaffer Road Santa Cruz CA 95060 USA kkroeker@ucsc.edu pointOfContact asNeeded Dataset Version: 1 Unknown Processing_date Season Type Species Hdr TankRep Ind_Rep Temp pH Tank_positions num_ind Amnt_ug d13C wt_pctC C_ug d15N wt_pctN N_ug CN quality_flag Notes Thermo-Scientific Conflo III CE Instruments NC2500 TITAN heat pump and Optima compact heaters, AquaLogic Thermo Scientific DELTAplus XP isotope ratio mass spectrometer Lachat QuikChem 8000 Flow Injection Analyzer FreeZone freeze drier, Labconco Metrohm 905 Titrando DuraFET Diving-PAM-II (Heinz Wlz GmbH) MINI-SPEC Shimadzu UV-1800 handheld meter (YSI) theme None, User defined date season sample type species scientific name (binomial) tank replicate treatment sample description number mass d13C measured in biota Elemental carbon (C) d15N measured in biota ratio quality flag comments featureType BCO-DMO Standard Parameters Aquarium Camera Continuous Flow Interface for Mass Spectrometers Elemental Analyzer Immersion heater Isotope-ratio Mass Spectrometer Lachat QuikChem 8000 flow injection analyzer and Ion Chromatography (IC) system Lyophilizer Metrohm 905 Titrando potentiometric titrator pH Sensor Photosynthetically Available Radiation Sensor UV Spectrophotometer-Shimadzu 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. CAREER: Energy fluxes and community stability in a dynamic, high-latitude kelp ecosystem https://osprey.bco-dmo.org/project/756735 CAREER: Energy fluxes and community stability in a dynamic, high-latitude kelp ecosystem <p><em>NSF Award Abstract:</em><br /> High latitude kelp forests support a wealth of ecologically and economically important species, buffer coastlines from high-energy storms, and play a critical role in the marine carbon cycle by sequestering and storing large amounts of carbon. Understanding how energy fluxes and consumer-resource interactions vary in these kelp communities is critical for defining robust management strategies that help maintain these valuable ecosystem services. In this integrated research and education program, the project team will investigate how consumer populations respond to variability in temperature, carbonate chemistry and resource quality to influence the food webs and ecosystem stability of kelp forests. A comprehensive suite of studies conducted at the northern range limit for giant kelp (Macrocystis pyrifera) in SE Alaska will examine how kelp communities respond to variable environmental conditions arising from seasonal variability and changing ocean temperature and acidification conditions. As part of this project, undergraduate and high school students will receive comprehensive training through (1) an immersive field-based class in Sitka Sound, Alaska, (2) intensive, mentored research internships, and (3) experiential training in science communication and public outreach that will include a variety of opportunities to disseminate research findings through podcasts, public lectures and radio broadcasts.</p> <p>Consumer-resource interactions structure food webs and govern ecosystem stability, yet our understanding of how these important interactions may change under future climatic conditions is hampered by the complexity of direct and indirect effects of multiple stressors within and between trophic levels. For example, environmentally mediated changes in nutritional quality and chemical deterrence of primary producers have the potential to alter herbivory rates and energy fluxes between primary producers and consumers, with implications for ecosystem stability. Moreover, the effects of global change on primary producers are likely to depend on other limiting resources, such as light and nutrients, which vary seasonally in dynamic, temperate and high latitude ecosystems. In marine ecosystems at high latitude, climate models predict that ocean acidification will be most pronounced during the winter months, when primary production is limited by light. This project is built around the hypothesis that there could be a mismatch in the energetic demands of primary consumers caused by warming and ocean acidification and resource availability and quality during winter months, with cascading effects on trophic structure and ecosystem stability in the future. Through complementary lab and field experiments, the project team will determine 1) how temperature and carbonate chemistry combine to affect primary consumer bioenergetics across a diversity of species and 2) the indirect effects of ocean acidification and warming on primary consumers via environmentally mediated changes in the availability, nutritional quality and palatability of primary producers across seasons. Using the data from the laboratory and field experiments, the project team will 3) construct a model of the emergent effects of warming and ocean acidification on trophic structure and ecosystem stability in seasonally dynamic, high latitude environments.</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> High latitude kelp dynamics largerWorkCitation project eng; USA oceans -135.414 -135.414 57.073 57.073 2020-02-28 2020-09-15 SE Alaskan coastal waters 0 BCO-DMO catalogue of parameters from Carbon and nitrogen data from kelp determined during seasonal global change experiments examining the effects of seasonal variation in light availability and nutrients on the response of three high-latitude kelp species 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/906504.rdf Name: Processing_date Units: unitless Description: <p>Collection and processing date (for field comparison individuals) or end-of-experiment processing date (for experimental individuals); recorded in local time zone (AKST)</p> http://lod.bco-dmo.org/id/dataset-parameter/906505.rdf Name: Season Units: unitless Description: <p>Seasonal experiment ID (Winter = experiment in Feb-March 2020, Summer = experiment in Aug-Sept 2020)</p> http://lod.bco-dmo.org/id/dataset-parameter/906506.rdf Name: Type Units: unitless Description: <p>Sample type (Field_control = kelp harvested from field and processed immediately for CN data; Experimental_ind = kelp used in experiments and processed at end of experiment for CN data)</p> http://lod.bco-dmo.org/id/dataset-parameter/906507.rdf Name: Species Units: unitless Description: <p>Kelp species (NFIM = Neoagarum fimbriatum, MPYR = Macrocystis pyrifera, HNIG = Hedophyllum nigripes)</p> http://lod.bco-dmo.org/id/dataset-parameter/906508.rdf Name: Hdr Units: unitless Description: <p>ID number (1-8) of header tank leading to experimental aquaria housing the kelp individual</p> http://lod.bco-dmo.org/id/dataset-parameter/906509.rdf Name: TankRep Units: unitless Description: <p>Replicate identifier (A, B, or C) of experimental aquaria nested within header, and housing the kelp individual</p> http://lod.bco-dmo.org/id/dataset-parameter/906510.rdf Name: Ind_Rep Units: unitless Description: <p>Replicate identifier (1-10 per species) for individuals collected as field controls</p> http://lod.bco-dmo.org/id/dataset-parameter/906511.rdf Name: Temp Units: unitless Description: <p>Temperature treatment factor (control = experimental control temp, OW = experimental OW treatment)</p> http://lod.bco-dmo.org/id/dataset-parameter/906512.rdf Name: pH Units: unitless Description: <p>pH treatment factor (control = experimental control temp, OA = experimental OA treatment)</p> http://lod.bco-dmo.org/id/dataset-parameter/906513.rdf Name: Tank_positions Units: unitless Description: <p>Indicator of which within-aquaria replicates of each species were pooled for this CN sample. Letters indicate relative location IDs (X, Y, or Z) within each aquaria. (X= closest to aquaria inflow, Y = middle of aquaria, Z = closest to aquaria outflow).</p> http://lod.bco-dmo.org/id/dataset-parameter/906514.rdf Name: num_ind Units: kelp individuals Description: <p>Number of individual kelp replicates (1-3) that had their tissue pooled for this sample</p> http://lod.bco-dmo.org/id/dataset-parameter/906515.rdf Name: Amnt_ug Units: micrograms (ug) Description: <p>Mass of dried algal tissue used for CN analysis. Precision to 1 ug</p> http://lod.bco-dmo.org/id/dataset-parameter/906516.rdf Name: d13C Units: per mil Description: <p>Carbon stable isotope ratio of algal tissue sample. Precision to 0.01 per mil</p> http://lod.bco-dmo.org/id/dataset-parameter/906517.rdf Name: wt_pctC Units: percent (%) Description: <p>Percentage of sample mass that was carbon. Precision to 0.1%</p> http://lod.bco-dmo.org/id/dataset-parameter/906518.rdf Name: C_ug Units: micrograms (ug) Description: <p>Total carbon mass in submitted sample. Precision to 1 ug.</p> http://lod.bco-dmo.org/id/dataset-parameter/906519.rdf Name: d15N Units: per mil Description: <p>Nitrogen stable isotope ratio of algal tissue sample. Precision to 0.01 per mil</p> http://lod.bco-dmo.org/id/dataset-parameter/906520.rdf Name: wt_pctN Units: percent (%) Description: <p>Percentage of sample mass that was nitrogen. Precision to 0.1%</p> http://lod.bco-dmo.org/id/dataset-parameter/906521.rdf Name: N_ug Units: micrograms (ug) Description: <p>Total nitrogen mass in submitted sample. Precision to 1 ug</p> http://lod.bco-dmo.org/id/dataset-parameter/906522.rdf Name: CN Units: unitless Description: <p>Carbon to nitrogen ratio of sample</p> http://lod.bco-dmo.org/id/dataset-parameter/906523.rdf Name: quality_flag Units: unitless Description: <p>Code for quality flag (y = contamination of sample, see notes; n = no issue)</p> http://lod.bco-dmo.org/id/dataset-parameter/906524.rdf Name: Notes Units: unitless Description: <p>Description of any processing errors</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 17860 https://darchive.mblwhoilibrary.org/server/api/core/bitstreams/69d4c622-aa57-40e9-920a-a46a5f1e1930/content download https://doi.org/10.26008/1912/bco-dmo.906469.1 download onLine dataset &lt;p&gt;To tease apart the effects of seasonal variation in light availability and nutrients on the response of high-latitude kelp species to pH and temperature, the investigators conducted two separate studies: a &quot;winter&quot; experiment from February 12 to March 18, 2020 (35 days), and a &quot;summer&quot; experiment from August 15 to September 16, 2020 (32 days). In the experimental design, analysis, and reporting, the investigators endeavored to follow best practices for OA research with macroalgae (Cornwall et al., 2012; Cornwall &amp;amp; Hurd, 2016). Both experiments took place at the Sitka Sound Science Center in a flow-through seawater system drawing source water from 20 meters (m) depth (MLLW) in Sitka Sound, Alaska. Incoming seawater was filtered to 20 micrometers (μm) and routed through a UV filter (Smart UV®, Pentair) before diverging into two temperature-controlled (TITAN® heat pump and Optima compact heaters, AquaLogic) recirculating tanks representing treatments for &quot;current&quot; or control temperatures (7° Celsius (C) in winter; 14°C in summer) and &quot;future&quot; ocean warming (OW) projections (11°C in winter; 18°C in summer) (IPCC, 2018) by season. From here, temperature-regulated seawater was pumped into eight header tanks where pH was maintained at setpoint levels for control conditions (pHT 7.6 in winter; pHT 7.9 in summer) and &quot;future&quot; ocean acidification (OA) projections (pHT 7.2 in winter; pHT 7.5 in summer) (Mathis et al., 2015) through a relay system (N = 2 header tanks per pH/temperature treatment). In both seasonal experiments, achievable pHT setpoints for control treatments were constrained by the ambient pH of incoming seawater and were, therefore, lower than the typical seasonal &lt;em&gt;in situ&lt;/em&gt; pHTminima observed on local rocky reefs by ~0.1 - 0.2 pH units (Kroeker et al., 2021). That said, the lower-than-average pH values of the control treatments did still fall within the observed pHs captured across all years of in situ environmental data. The investigators chose to maintain the projected end-of-century pH offset for this region (~0.4 pH units) to define the OA treatment setpoints relative to achievable control pH levels. A DuraFET sensor (Honeywell) in each header tank communicated real-time pH measurements to a controller (UDA 2152, Honeywell) that regulated injection of pre-equilibrated low pH seawater through solenoid valves into the headers to maintain pH at treatment set points. The low pH (~6) seawater was produced by bubbling pure CO2 gas into two tanks of seawater flowing from each temperature-controlled tank. Once in each header tank, the CO2 and temperature-equilibrated seawater was continuously mixed before delivery to 24 experimental aquaria (N = 3 aquaria per header) at an average flow-through rate of 2-2.5 liters per minute per aquaria (L min-1 aquaria-1). The &quot;Header pH and Temperature&quot; Supplemental File (2020_kelpGCexps_headerdata.csv) contains a summary of the calibrated pH and temperature data recorded by the Durafet sensors in each header during the experiments.&lt;/p&gt; &lt;p&gt;Seawater nutrient concentrations were not manipulated and thus reflected what was delivered through source water inflow to the system during each experiment. Terrestrial outflow from heavy precipitation over Southeast Alaska’s temperate rainforests and wind stress dynamics in the Gulf of Alaska control nutrient supply onto the Northeast Pacific shelves (Hermann et al., 2009; Hood &amp;amp; Scott, 2008; Ladd &amp;amp; Cheng, 2016; Stabeno et al., 2016). The complexities of how climate change may impact these drivers in tandem with altered phytoplankton productivity (Ji et al., 2010) means that there is little consensus on how seasonal nutrient supply into Sitka Sound may change. Therefore, the investigators chose to assume that nutrient availability, like seasonal light availability, would not differ significantly in this region in the future. All aquaria were fitted with a full-spectrum light (Aqua Illumination) that provided seasonally relevant regimes of photosynthetically active radiation spectra and photoperiod within the aquaria based on observations during overcast days in Sitka Sound (Bell et al., 2022). The entire experimental system was shielded from external light sources, and aquaria positions were randomized by treatment and location in the laboratory to minimize spatial variation among the random factors &lt;em&gt;aquaria&lt;/em&gt; and &lt;em&gt;header&lt;/em&gt;. The &quot;Nutrient Concentrations with Experimental Aquaria&quot; Supplemental File (2020_kelpGCexps_nutrients.csv) contains the data on nutrient concentrations within experimental aquaria.&lt;/p&gt; &lt;p&gt;At the beginning, middle, and end of each experiment, discrete water samples were collected for the determination of pHT, TA, and nutrient concentrations in each aquarium and header tank. Water samples were collected without aeration and poisoned with saturated HgCl2 (0.025%) in glass bottles within 20 minutes. Airtight samples were transported to the University of California Santa Cruz (UCSC) for analysis within 9 months of collection. pH was measured spectrophotometrically (Shimadzu, UV-1800) using m-cresol purple following best practices (Dickson et al., 2007). Total alkalinity (TA) was measured using open cell titration (Metrohm, 905 Titrandro) and corrected against certified reference materials of CO2 in seawater (Dickson laboratory, Scripps Institute of Oceanography). Water chemistry samples from each tank had a mean standard error of 0.0013 pH units and 0.87 micromoles per kilogram seawater (μmol kg-1 SW-1) among sample triplicates. To calculate in situ pH on the total hydrogen ion concentration scale (pHT; mol kg-1 SW-1)(Dickson, 1993), the investigators used their laboratory measurements of spectrophotometric pH and TA, measurements of temperature and salinity recorded with a handheld meter (YSI) concurrently with discrete water sample collection, and stoichiometric dissociation constants (Dickson &amp;amp; Millero, 1987; Mehrbach et al., 1973) as inputs to the program CO2SYS (Lewis &amp;amp; Wallace, 1998; Pierrot et al., 2006). Corrections were applied to the continuous time series of pH values recorded by durafets in each header during each experiment by calculating an average offset from pHT values calculated from discrete samples.&lt;/p&gt; &lt;p&gt;Kelp used in both winter and summer experiments came from 4.5-7.5 m depth at Talon Island (57.073 N, 135.414 W), Sitka Sound. These experimental &quot;individuals&quot; were collected as whole thalli (&lt;em&gt;Neoagarum fimbriatum&lt;/em&gt; and &lt;em&gt;Hedophyllum nigripes&lt;/em&gt;), or as single blades with their attached pneumatocysts that were cut from young sporophytes at approximately 1 m above their holdfasts (&lt;em&gt;Macrocystis pyrifera&lt;/em&gt;). During transport to the laboratory and prior to the start of the experiments (less than 2 days), all algae was held continuously in ambient flow-through seawater (winter experiment: ~6°C, pHT 7.8; summer experiment: ~13.5°C, pHT 8.0). Individuals were removed briefly only to clean off epiphytes and to record initial morphometrics (maximum blade length, total wet mass) after trimming all blades to 10 centimeters (cm) total length. The investigators took pictures of each trimmed blade to estimate total surface area using ImageJ (NIH v1.8.0).&lt;/p&gt; &lt;p&gt;In both the winter and summer experiments, 3 individuals of each kelp species were randomly assigned to each experimental aquaria (N = 18 individuals per species per treatment). The investigators affixed individuals upright in aquaria by placing their stipes or pneumatocysts through three-strand line suspended over the open ends of 5 cm tall PVC stands. After all seaweeds were processed for initial morphometrics, pH and temperature were gradually changed in treatment tanks stepwise over the course of 3 days to reach final setpoints. During the experiment, kelps were visually checked daily for necrosis and were lightly brushed biweekly during aquaria cleaning to remove diatoms.&lt;/p&gt; &lt;p&gt;At the end of each experiment, individuals were measured and photographed for final morphometrics. Due to the difficulty in capturing three-dimensional tissue growth and the error inherent in wet mass measurements, kelp growth rates were estimated using three different metrics: wet mass in grams (g), maximum blade length in centimeters (cm), and total blade surface area in square centimeters (cm²). The initial (Ginitial) and final (Gfinal) measurements of each metric were used to calculate three relative growth rates (RGR; percent per day (% d-1)) for each individual using Equation 1 (see the attached Supplemental File), where Δt (days (d)) represents the total number of days elapsed between the beginning and end of the experiment. Relative growth rates were used for subsequent statistical analyses of experimental results. Absolute blade length extension rates were used to compare experimental growth to &lt;em&gt;in situ&lt;/em&gt; kelp growth measurements (Bell &amp;amp; Kroeker, 2022).&lt;/p&gt; &lt;p&gt;From each individual, the investigators excised new blade tissue grown during the experiment adjacent to the intercalary meristem and pooled this tissue for all species replicates in each aquarium. A portion of this tissue was frozen at -20°C for use in feeding assays. The other portion of this tissue was dried at 60°C for &amp;gt;24 hours and analyzed for nitrogen (N) content (% dry mass) and δ13C values by the UCSC Stable Isotope Laboratory using a CE Instruments NC2500 elemental analyzer coupled to a Thermo Scientific DELTAplus XP isotope ratio mass spectrometer via a Thermo-Scientific Conflo III (routine measurement error ≤ 1.0 %C and ≤ 0.2 %N). The investigators also analyzed blade tissue from non-experimental kelp individuals collected at Talon Islands in each season (&quot;field controls&quot;; N=6 species-1 season-1) for elemental and isotopic analysis.&lt;/p&gt; &lt;p&gt;To compare &lt;em&gt;in situ&lt;/em&gt; nutrient and light data with aquaria conditions during the experiment, environmental data was collected at the Talon Island experimental collection site. Benthic seawater was collected for the determination of nutrient concentrations in February and August 2020 (N=3 samples-1 season-1). Seawater for nutrient samples was immediately filtered through a 0.2 µm filter and frozen until analysis for dissolved inorganic nitrogen content as NOx (NO3 + NO2) and ammonium (NH4+) on a Lachat QuikChem 8000 Flow Injection Analyzer at the University of California Santa Cruz Marine Analytical Laboratory (detection limits: &amp;lt; 0.28 µM NOx, &amp;lt; 2.40 µM NH4; average run measurement error &amp;lt; 0.1 µM NOx &amp;lt; 0.8 µM NH4). A Diving-PAM-II (Heinz Wlz GmbH) MINI-SPEC was used to haphazardly record the photosynthetic photon flux density (PPFD; micromoles per square meter per second (µmol m-2 s-1) reaching the benthos at more than 10 locations along the ~5 m depth contour on two clear days in winter (February 28) and summer (September 19).&lt;/p&gt; &lt;p&gt;Tissue from &lt;em&gt;H. nigripes&lt;/em&gt; and &lt;em&gt;N. fimbriatum&lt;/em&gt; individuals grown in the laboratory was used to investigate whether future ocean conditions affect the palatability of these understory kelp species in either season. In April 2021, methods used by Hay et al. (1994) were modified to create &quot;gels&quot; of homogenized kelp tissue suspended in agar and enmeshed in squares of window screen. Each 30 cm² gel was formed from 0.1547 ± 0.0004 g (mean ± SE) of freeze-dried (FreeZone, Labconco) &lt;em&gt;H. nigripes&lt;/em&gt; or &lt;em&gt;N. fimbriatum&lt;/em&gt; tissue growth in either the control treatment or the combination OW and OA treatment from each seasonal experiment. The total number of gels used for the feeding assays was limited by the available kelp tissue grown during each experiment, and was consequently lower for gels made from tissue grown in the winter experiment (&lt;em&gt;H. nigripes&lt;/em&gt;: N = 11 gels per treatment, &lt;em&gt;N. fimbriatum&lt;/em&gt;: N = 12 gels per treatment) versus the summer experiment (&lt;em&gt;H. nigripes&lt;/em&gt;: N = 24 gels per treatment, &lt;em&gt;N. fimbriatum&lt;/em&gt;: N = 23 gels per treatment). Palatability assays were run by feeding these seaweed gels to the common kelp forest grazer, &lt;em&gt;Strongylocentrotus droebachiensis&lt;/em&gt; (green urchin). Urchins with a test diameter of 24 ± 3 millimeters (mm) were collected from the intertidal, starved for 48 hours, and then placed in a flow-through chamber with a single gel in ambient seawater conditions (~7 °C, ~8.0 pH) for 48 hours. Photographs were taken of each gel before and after the assay and the relative consumption of seaweeds grown under different treatments was determined using Image J (NIH v1.8.0).&lt;/p&gt; Specified by the Principal Investigator(s) &lt;p&gt;To calculate &lt;em&gt;in situ &lt;/em&gt;pH of water samples taken from laboratory aquaria on the total hydrogen ion concentration scale (pHT; moles per kilogram seawater (mol kg-1 SW-1)) (Dickson, 1993), the investigators used their laboratory measurements of spectrophotometric pH and TA, measurements of temperature and salinity recorded with a handheld meter (YSI) concurrently with discrete water sample collection, and stoichiometric dissociation constants (Dickson &amp;amp; Millero, 1987; Mehrbach et al., 1973) as inputs to the program CO2SYS (Lewis &amp;amp; Wallace, 1998; Pierrot et al., 2006). They corrected the continuous timeseries of pH values recorded by durafets in each header during each experiment by calculating an average offset from pHT values calculated from discrete samples. R (R Core Team) was used for data processing of durafet sensor data recorded within experiment header tanks.&lt;/p&gt; &lt;p&gt;The image processing software ImageJ (NIH v1.8.0) was used for morphometric analysis of experimental kelp blades at the beginning and end of manipulative experiments, as well as to calculate the urchins' consumption of seaweed gels over the course of feeding assays.&lt;/p&gt; &lt;p&gt;Quality flags are used to indicate instances where experimental individuals degraded during the experiment, potentially compromising physiological data.&lt;/p&gt; Specified by the Principal Investigator(s) - Imported original file &quot;2020_kelpGCexps_CNdata.csv&quot; into the BCO-DMO system. - Converted the date column to the format YYYY-MM-DD. - Renamed fields to comply with BCO-DMO naming conventions. - Saved the final file as &quot;906469_v1_carbon_and_nitrogen.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 PI Supplied Instrument Name: Instrument Name: Aquarium Instrument Short Name:Aquarium Instrument Description: Aquarium - a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept PI Supplied Instrument Name: Instrument Name: Camera Instrument Short Name:camera Instrument Description: All types of photographic equipment including stills, video, film and digital systems. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/311/ Thermo-Scientific Conflo III Thermo-Scientific Conflo III PI Supplied Instrument Name: Thermo-Scientific Conflo III PI Supplied Instrument Description:Dried tissue was analyzed for nitrogen content and δ13C values by the UCSC Stable Isotope Laboratory using a CE Instruments NC2500 elemental analyzer coupled to a Thermo Scientific DELTAplus XP isotope ratio mass spectrometer via a Thermo-Scientific Conflo III. Instrument Name: Continuous Flow Interface for Mass Spectrometers Instrument Short Name: Instrument Description: A Continuous Flow Interface connects solid and liquid sample preparation devices to instruments that measure isotopic composition. It allows the introduction of the sample and also reference and carrier gases. Examples: Finnigan MATConFlo II, ThermoScientific ConFlo IV, and Picarro Caddy. Note: This is NOT an analyzer CE Instruments NC2500 CE Instruments NC2500 PI Supplied Instrument Name: CE Instruments NC2500 PI Supplied Instrument Description:Dried tissue was analyzed for nitrogen content and δ13C values by the UCSC Stable Isotope Laboratory using a CE Instruments NC2500 elemental analyzer coupled to a Thermo Scientific DELTAplus XP isotope ratio mass spectrometer via a Thermo-Scientific Conflo III. Instrument Name: Elemental Analyzer Instrument Short Name: Instrument Description: Instruments that quantify carbon, nitrogen and sometimes other elements by combusting the sample at very high temperature and assaying the resulting gaseous oxides. Usually used for samples including organic material. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB01/ TITAN heat pump and Optima compact heaters, AquaLogic TITAN heat pump and Optima compact heaters, AquaLogic PI Supplied Instrument Name: TITAN heat pump and Optima compact heaters, AquaLogic Instrument Name: Immersion heater Instrument Short Name:Immersion heater Instrument Description: Submersible heating element for water tanks and aquaria. Thermo Scientific DELTAplus XP isotope ratio mass spectrometer Thermo Scientific DELTAplus XP isotope ratio mass spectrometer PI Supplied Instrument Name: Thermo Scientific DELTAplus XP isotope ratio mass spectrometer PI Supplied Instrument Description:Dried tissue was analyzed for nitrogen content and δ13C values by the UCSC Stable Isotope Laboratory using a CE Instruments NC2500 elemental analyzer coupled to a Thermo Scientific DELTAplus XP isotope ratio mass spectrometer via a Thermo-Scientific Conflo III. 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/ Lachat QuikChem 8000 Flow Injection Analyzer Lachat QuikChem 8000 Flow Injection Analyzer PI Supplied Instrument Name: Lachat QuikChem 8000 Flow Injection Analyzer PI Supplied Instrument Description:Analysis for dissolved inorganic nitrogen content as NOx (NO3 + NO2) and ammonium (NH4+) was done on a Lachat QuikChem 8000 Flow Injection Analyzer at the University of California Santa Cruz Marine Analytical Laboratory. Instrument Name: Lachat QuikChem 8000 flow injection analyzer and Ion Chromatography (IC) system Instrument Short Name: Instrument Description: The Lachat QuikChem 8000 can operate flow injection analysis and ion chromatography simultaneously and independently on the same instrument platform. Instrument includes sampler, dilutor, sampling pump, electronics unit, and data station. Analysis takes 20-60 seconds, with a sample throughput of 60-120 samples per hour. Measurements are in the range of parts per trillion to parts per hundred. FreeZone freeze drier, Labconco FreeZone freeze drier, Labconco PI Supplied Instrument Name: FreeZone freeze drier, Labconco Instrument Name: Lyophilizer Instrument Short Name:freeze dryer Instrument Description: A lyophilizer, also known as freeze dryer or liofilizador, is a device that is used to freeze-dry material. Metrohm 905 Titrando Metrohm 905 Titrando PI Supplied Instrument Name: Metrohm 905 Titrando PI Supplied Instrument Description:total alkalinity (TA) was measured using open cell titration (Metrohm, 905 Titrandro) Instrument Name: Metrohm 905 Titrando potentiometric titrator Instrument Short Name: Instrument Description: The Metrohm 905 Titrando potentiometric titrator is a modular potentiometric titrator for dynamic, monotonic, and set endpoint titrations. The device includes magnetic stirrers, rod stirrers, and a titration stand. It can be connected to various dosing units which include a buret and are attached to the reagent. Operation is carried out by means of a touch-sensitive display or with high-performance PC software. Temperature is measured by a Pt1000 or NTC. Ranges of the outputs are -13 to 20 pH, -1200 to 1200 mV, and -150 to 250 deg. C (Pt1000) or -5 ro 250 deg. C (NTC). Resolutions of the outputs are 0.001 for pH, 0.1 for mV, 0.1 deg. C for temperature. The measuring interval is of 100 ms. Works in conditions from 5 to 45 deg. C and at a maximum of 80 % relative humidity. DuraFET DuraFET PI Supplied Instrument Name: DuraFET PI Supplied Instrument Description:A DuraFET sensor (Honeywell) in each header tank communicated real-time pH measurements to a controller. Instrument Name: pH Sensor Instrument Short Name:pH Sensor Instrument Description: An instrument that measures the hydrogen ion activity in solutions. The overall concentration of hydrogen ions is inversely related to its pH.  The pH scale ranges from 0 to 14 and indicates whether acidic (more H+) or basic (less H+).  Diving-PAM-II (Heinz Wlz GmbH) MINI-SPEC Diving-PAM-II (Heinz Wlz GmbH) MINI-SPEC PI Supplied Instrument Name: Diving-PAM-II (Heinz Wlz GmbH) MINI-SPEC PI Supplied Instrument Description:A Diving-PAM-II (Heinz Wlz GmbH) MINI-SPEC was used to haphazardly record the photosynthetic photon flux density. Instrument Name: Photosynthetically Available Radiation Sensor Instrument Short Name:PAR sensor Instrument Description: A PAR sensor measures photosynthetically available (or active) radiation. The sensor measures photon flux density (photons per second per square meter) within the visible wavelength range (typically 400 to 700 nanometers). PAR gives an indication of the total energy available to plants for photosynthesis. This instrument name is used when specific type, make and model are not known. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/122/ Shimadzu UV-1800 Shimadzu UV-1800 PI Supplied Instrument Name: Shimadzu UV-1800 PI Supplied Instrument Description:pH was measured spectrophotometrically (Shimadzu, UV-1800) Instrument Name: UV Spectrophotometer-Shimadzu Instrument Short Name:UV Spectrophotometer-Shimadzu Instrument Description: The Shimadzu UV Spectrophotometer is manufactured by Shimadzu Scientific Instruments (ssi.shimadzu.com). Shimadzu manufacturers several models of spectrophotometer; refer to dataset for make/model information. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB20/ handheld meter (YSI) handheld meter (YSI) PI Supplied Instrument Name: handheld meter (YSI) PI Supplied Instrument Description:measurements of temperature and salinity recorded with a handheld meter (YSI) 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.