Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
  • BCO-DMO Curation Notes
  • Problem Description
• Data Files
• Related Publications
• Parameters
• Instruments
• Project Information
• Funding

All censusing was done from shore or with small boats. Sampling stations were established on the shoreline of Tatoosh Island and adjacent offshore sites to the east of the island beginning in August 1998. Seven of the sites (Finger, Glacier Control, Hedophyllum Cove, Ladd's Finger, Simon's Landing, Strawberry Point, Toad Point) corresponded to wave-exposed shores on the periphery of the island used in a prior nutrient manipulation experiment (Wootton et al. 1996), and an eighth (Northwest Point) was another wave-exposed shore selected to expand peripheral coverage of the island. Two additional relatively wave-sheltered sites were also added to the sampling, both located inside extensive kelp beds: Main Beach and Strawberry Draw. Water at all these sites was collected 2-3 hours after a strong spring tide on a day when the investigators were departing from the island to facilitate rapid sample freezing. Water samples were collected in 2001, 2015, 2016, and 2022 at an additional shoreline site (Hydrolab Pool) subject to intensive sampling of ocean conditions. In 2000, four offshore sampling sites were established at varying distances from the island (Inside Kelp, ~30 meters (m); Outside Kelp, ~100 m; Gut, ~0.6 kilometers (km); Mushroom Rocks, ~ 1.8 km from island, ~0.5 km from the mainland). Water at the offshore sites was collected by boat approximately 4-5 hours after the tide. Water was extracted from the ocean at the surface using 50-milliliter (mL) syringes, which were first rinsed in the water at the site before a sample was drawn. The sample was then pushed through a syringe filter loaded with a disk of Whatman GF/F glass fiber filter paper, and collected in 40 mL acid-washed Nalgene bottles, leaving enough headspace to allow water expansion when frozen.

Water samples were kept in coolers following collection and immediately frozen at -20 degrees Celsius upon return to the mainland field base. Frozen water samples were express shipped to the University of Washington Ocean Chemistry Laboratory, where they were analyzed following the methods outlined in (UNESCO 1994) using a Seal Analytical AA3 nutrient autoanalyzer. In 2025, the analysis of samples from all dates/sites was carried out by the Moss Landing Marine Laboratory Environmental Analytical Laboratory, by colorimetric analysis using a Lachat QuickChem 8000 Flow Injection Analyzer and 50 mL Falcon Tubes as sample containers. We sent duplicate samples from 29 May 2025 and 23 August 2025 to the University of Washington Marine Chemistry Laboratory for comparative purposes.

No significant data processing, except in 2025, where relationships between University of Washington and Moss Landing labs were developed and data transformed following these relationships to make Moss Landing analyzed samples more equivalent to University of Washington samples for sample dates without University of Washington lab analysis. The relationships were derived from linear regression on log-transformed data of University of Washington nutrient data on Moss Landing nutrient data for each nutrient considered.

- Imported the original file "Tatoosh Water Nutrients Long BCODMO.csv" into the BCO-DMO data processing system.
- Renamed column Si(OH)4 to SiOH4 to comply with BCO-DMO naming conventions.
- Converted Date and Time columns (parsed as %Y-%m-%d and %H:%M respectively) into new datetime column ISO_DateTime_Local, formatted as %Y-%m-%dT%H:%M.
- Converted Date and Time columns (local Pacific time, PST8PDT) into a new datetime column ISO_DateTime_UTC, converting to UTC and formatted as %Y-%m-%dT%H:%MZ.
- Saved the final file as "1004161_v1_tatoosh_island_nutrient_data.csv".

NSF Award Abstract:
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 Nereocystis luetkeana. 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.

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. Nereocystis luetkeana, 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.

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.