*************************Data Package Abstract*** *************************** Version 1.0, April 8, 2016 This is a metadata file that describes csv files associated with: Williams, J.J. et al. 2016. Phytoplankton Responses to Nitrogen Enrichment in Pacific Northwest, USA Mountain Lakes. Hydrobiologia. (DOI: 10.1007/s10750-016-2758-y) ********************Data Package Contents*********************************** 1.'read_me.txt' (this file) 2. experiments_phyto.csv: phytoplankton taxa cell density data from in situ bioassays described in DOI: 10.1007/s10750-016-2758-y. 3. chla_csv: phytoplankton biomass (chlorophyll a) data from in situ bioassays described in DOI: 10.1007/s10750-016-2758-y. 4. 'park_lakes_db.csv' a database with 675 dissolved inorganic nitrogen (NO3-N and NH3-N) observations from lakes above 1,200 m sampled between 1988 and 2014 across Mount Rainier, North Cascades, and Olympic National Parks. The database was compiled by Jason Williams from raw data provided to JW by National Park Service and US Geological Survey staff. See notes about park_lakes_db.csv below. ********************Contact************************************************* Jason Williams, Washington State University (jason.williams2@wsu.edu) *********************Data Usage Rights************************************* There are no use restrictions after manuscript publication. However, please cite this data package and the associated Hydrobiologia publication in any documents, publications, or presentations where the data are used. *********************Geographic Coverage-********************************** Copper Lake (North Cascades National Park) (48.918449 N, -121.451562 W) Doubtful Lake (North Cascades National Park) (48.474162 N, -121.047925 W) Rainbow Lake (North Cascades National Park) (48.40224 N, -120.739707 W) Hidden Lake (Mount Rainier National Park) (46.941521 N, -121.59966 W) Lake Allen (Mount Rainier National Park) (46.765005 N, -121.892992 W) Lake LH15 (Mount Rainier National Park) (46.953533 N, -121.619128 W) Hoh Lake (Olympic National Park) (47.898843 N, -123.786219 W) Crazy Lake (Olympic National Park) (47.619757 N, -123.177973 W) Heather Lake (Olympic National Park) (47.785258 N, -123.177973) *********************Data Time Period************************************** 2013-2014 *********************Methods Description*********************************** We used in situ nutrient-enrichment experiments in nine mountain lakes to characterize phytoplankton species and biomass responses to N enrichment, and associated response thresholds. Experiments were designed to i) classify species and biomass nutrient limitation (N limitation, P limitation, co-limiatation), ii), quantify Monod growth parameters for species sensitive to lake N enrichment, and iii) quantify biomass responses to an increasing N concentration gradient. At each lake, a 30-40 L volume of water was collected into 4 L LDPE cubitainers using a battery-powered submersible sampling pump and Tygon tubing. The pump and Tygon tubing were flushed with lake water for 2-3 minutes prior to collecting experimental water. Large-bodied zooplankton were screened out using 100 μm Nitex mesh on the pump intake. Water was collected from approximately one half of the Secchi depth, or at half the maximum lake depth (“mid depth”) if the Secchi disk could be seen on the lake bottom. Collected water was subsampled to establish the initial chlorophyll a (Chl a), nutrient chemistry, and phytoplankton community composition. Triplicate Chl a samples were collected by filtering a known volume of water through 0.7-μm Whatman GF/F filters. Filters were placed in petri dishes and wrapped in aluminum foil. Three 60 mL subsamples were preserved with Lugol’s iodine solution to determine initial phytoplankton community composition and species densities. A 60 mL subsample was filtered through a pre-rinsed 0.4-μm polycarbonate filter into a HCl-washed bottle for analysis of dissolved nitrate, ammonium, and orthophosphate. An additional 60 mL subsample was filtered for analysis of dissolved silica (Si). A120 mL unfiltered subsample was collected into a HCl-washed bottle for analysis of total phosphorus (TP). All bottles were rinsed three times with sample water before filling. Filters and water samples were stored in a cooler bag packed with snow in the field. Upon return, filters and N and P samples were frozen, and Si and phytoplankton samples were refrigerated until analysis. After subsampling, collected water was divided among clean 1 L LDPE cubitainers that were pre-rinsed three times with lake water. To classify species and biomass nutrient limitation, four treatments were established (control, N, P, N+P). Treatments receiving N had 112 μg N L-1 added in the form of NaNO3; treatments receiving P had 31 μg P L-1 added as NaH2PO4. These treatments were run in triplicate. To quantify growth kinetics of key species as well as biomass responses to an increasing N concentration gradient, six additional treatments were established in triplicate with 0.14, 0.7, 1.4, 7, 14, and 56 μg N L-1. Phosphorus and silica (2.8 mg Si L-1 added as Na2SiO3) were also added to these N gradient treatments to isolate responses to N additions. The 56 μg N L-1 treatment was not used at North Cascades National Park lakes. Cubitainers were suspended in each lake for 7-11 d, depending on access constraints. Three replicate buoys, each with one treatment replicate, were anchored to the lake bottom. After incubation, each cubitainer was subsampled for Chl a and phytoplankton taxonomy using procedures described above for initial sampling. Chl a filters were extracted in 10 ml of 90% acetone within three weeks of collection. The extract was then clarified by centrifugation and analyzed for Chl a using a Shimadzu RF-501 spectrofluorometer (emission at 670 nm, excitation at 430 nm light). Chl a samples were not corrected for pheophytin interference. Detection limits, defined as 3 times the mean of filter blanks, were 0.04 μg L-1 or less in each analytical run, and all results were above detection limits. Water samples were analyzed for nutrients using standard methods (APHA). N and P analyses were performed using a Seal Analytical AA3 Auto-Analyzer at the WSU School of the Environment Water Quality Laboratory according to standard methods (APHA). Detection limits were 1-2 μg N L-1 for nitrate plus nitrite, 4 μg N L-1 for ammonium, 2 μg P L-1 for ortho-phosphate and TP. Si analyses were performed at the Oregon State University Cooperative Chemical Analytical Laboratory using a Technicon Auto-Analyzer II using standard method 4500-SiO2 E. Phytoplankton samples were settled in an Utermöhl -style chamber and identified to the lowest practical level (typically species or genus, based on Wehr & Sheath (2003) under 400 or 600x magnification on a Nikon TS100 inverted microscope. A minimum of 300 individuals were counted per sample. *****************experiments_phyto.csv Column Definitions****************** *note: all cell densities (columns END.1A-END.10C) have units of cells/mL, except for taxa that labeled as colonies, which have units colonies/mL Park: acronym for park: NOCA (North Cascades National Park), MORA (Mount Rainier National Park), OLYM (Olympic National Park) Lake: Lake name Taxa: taxa name, assigned by Andrea Nurse at University of Maine Phylum: phylum assigned to taxa initial: taxa cell density in initial lake water (replicate 1) initial.1: taxa cell density in initial lake water (replicate 2) initial.2: taxa cell density in initial lake water (replicate 3) END.1A: taxa cell density in control treatment after incubation (replicate 1) END.1B: taxa cell density in control treatment after incubation (replicate 2) END.1C: taxa cell density in control treatment after incubation (replicate 3) END.2A: taxa cell density in 0.14 ug N + 31 ug P + 2.8 mg Si treatment after incubation (replicate 1) END.2B: taxa cell density in 0.14 ug N + 31 ug P + 2.8 mg Si treatment after incubation (replicate 2) END.2C: taxa cell density in 0.14 ug N + 31 ug P + 2.8 mg Si treatment after incubation (replicate 3) END.3A: taxa cell density in 0.7 ug N + 31 ug P + 2.8 mg Si treatment after incubation (replicate 1) END.3B: taxa cell density in 0.7 ug N + 31 ug P + 2.8 mg Si treatment after incubation (replicate 2) END.3C: taxa cell density in 0.7 ug N + 31 ug P + 2.8 mg Si treatment after incubation (replicate 3) END.4A: taxa cell density in 1.4 ug N + 31 ug P + 2.8 mg Si treatment after incubation (replicate 1) END.4B: taxa cell density in 1.4 ug N + 31 ug P + 2.8 mg Si treatment after incubation (replicate 2) END.4C: taxa cell density in 1.4 ug N + 31 ug P + 2.8 mg Si treatment after incubation (replicate 3) END.5A: taxa cell density in 7 ug N + 31 ug P + 2.8 mg Si treatment after incubation (replicate 1) END.5B: taxa cell density in 7 ug N + 31 ug P + 2.8 mg Si treatment after incubation (replicate 2) END.5C: taxa cell density in 7 ug N + 31 ug P + 2.8 mg Si treatment after incubation (replicate 3) END.6A: taxa cell density in 14 ug N + 31 ug P + 2.8 mg Si treatment after incubation (replicate 1) END.6B: taxa cell density in 14 ug N + 31 ug P + 2.8 mg Si treatment after incubation (replicate 2) END.6C: taxa cell density in 14 ug N + 31 ug P + 2.8 mg Si treatment after incubation (replicate 3) END.7A: taxa cell density in 56 ug N + 31 ug P + 2.8 mg Si treatment after incubation (replicate 1) END.7B: taxa cell density in 56 ug N + 31 ug P + 2.8 mg Si treatment after incubation (replicate 2) END.7C: taxa cell density in 56 ug N + 31 ug P + 2.8 mg Si treatment after incubation (replicate 3) END.8A: taxa cell density in 31 ug P treatment after incubation (replicate 1) END.8B: taxa cell density in 31 ug P treatment after incubation (replicate 2) END.8C: taxa cell density in 31 ug P treatment after incubation (replicate 3) END.9A: taxa cell density in 112 ug N treatment after incubation (replicate 1) END.9B: taxa cell density in 112 ug N treatment after incubation (replicate 2) END.9C: taxa cell density in 112 ug N treatment after incubation (replicate 3) END.10A: taxa cell density in 112 ug N + 31 ug P treatment after incubation (replicate 1) END.10B: taxa cell density in 112 ug N + 31 ug P treatment after incubation (replicate 2) END.10C: taxa cell density in 112 ug N + 31 ug P treatment after incubation (replicate 3) *************************chla.csv Column Definitions************************** Park: acronym for park: NOCA (North Cascades National Park), MORA (Mount Rainier National Park), OLYM (Olympic National Park) Lake_Code: unique code for each lake Lake: lake name Sample_Date: date water was collected and filtered in the field Treatment: treatment name Treatment_N_ug: ug N added to treatment Treatment_P_ug: ug P added to treatment Treatment_Category: types of additions used in treatment (N, P, N+P, or N+P+Si) chl_a_ugL: chlorophyll a (ug/L) ************************park_lakes_db.csv Column Definitions******************** Park: Park: acronym for park: NOCA (North Cascades National Park), MORA (Mount Rainier National Park), OLYM (Olympic National Park) Lake_Code: unique code for each lake Name: lake name Elev_m: lake elevation above sea level (m) Sample_Date: date water sample was collected Sample Year: year water sample was collected Sample_Depth_m: sample depth (m below lake surface) NO3_N_mgL: NO3-N concentration in lake water (mg N/L) NO3_N_qual: qualifier for NO3_N_mgL value; 'bd' indicates result is below detection limit NH3_N_mgL: NH3-N concentration in lake water (mg N/L) NH3_N_qual: NH3_N_qual qualifier for NH3_N_mgL value; bd indicates result is below detection limit ***NOTE: see additional notes below*** ************************additional notes about park_lakes_db.csv****************** 'park_lakes_db.csv' is a database of water chemistry data from lakes above 1200 m in the three parks that was assembled by Jason Williams for the analyses in Williams et al. 2016. It not an 'official' data product of the National Park Service. Data were compiled from 4 sources: 1. lake surveys conducted between 1989 and 1999 by the U.S. Geological Survey (USGS) (https://www.sciencebase.gov/catalog/item/51ee3834e4b00ffbed48f511) 2. unpublished data provided by National Park Service staff at NOCA, MORA, and OLYM, 3. Sheibley et al. 2014 Water Air and Soil Pollution 255: 1857 Table 3 4. Williams et al. 2016 Table 2 Please note that some NPS data used to create the database had not gone through NPS' full data certification process at the time the 'park_lakes_db.csv' was assembled. Data users are strongly encouraged to contact NPS North Coast and Cascades Network data management or aquatic ecology staff for more detailed information about the origin of these data, or to access a larger and more and up to date data set before using 'park_lakes_db.csv' data (http://science.nature.nps.gov/im/units/nccn/about.cfm). At the time of this writing, NPS staff are in the process of assembling mountain lakes data collected through the NCCN mountain lakes monitoring program into a database.