Diatoms (Bacillariophyta) of the Salish Sea, Northeast Pacific (1866–2026)

Data Records

The data in this occurrence resource has been published as a Darwin Core Archive (DwC-A), which is a standardized format for sharing biodiversity data as a set of one or more data tables. The core data table contains 6,725 records.

This IPT archives the data and thus serves as the data repository. The data and resource metadata are available for download in the downloads section. The versions table lists other versions of the resource that have been made publicly available and allows tracking changes made to the resource over time.

Versions

The table below shows only published versions of the resource that are publicly accessible.

How to cite

Researchers should cite this work as follows:

Simon A, Webber M, van Asselt A (2026). Diatoms (Bacillariophyta) of the Salish Sea, Northeast Pacific (1866–2026). Version 1.7. Biodiversity Data Journal. Occurrence dataset. https://ipt.pensoft.net/resource?r=salishseadiatoms&v=1.7

Rights

Researchers should respect the following rights statement:

The publisher and rights holder of this work is Biodiversity Data Journal. This work is licensed under a Creative Commons Attribution (CC-BY 4.0) License.

GBIF Registration

This resource has been registered with GBIF, and assigned the following GBIF UUID: d41f9582-0b3e-4062-8ee0-31f0ba52ace1.  Biodiversity Data Journal publishes this resource, and is itself registered in GBIF as a data publisher endorsed by GBIF Bulgaria.

Keywords

Occurrence; diatom; phytoplankton; voucher specimens; scanning electron microscopy; light microscopy; amplicon; metabarcoding; eDNA; Sanger sequencing; Occurrence; diatom; phytoplankton; voucher specimens; scanning electron microscopy; light microscopy; amplicon; metabarcoding; eDNA; Sanger sequencing

External data

The resource data is also available in other formats

Contacts

Geographic Coverage

The study was conducted in the Salish Sea, an inland marine system of the northeastern Pacific Ocean spanning coastal British Columbia (Canada) and Washington State (USA). The region includes the Strait of Georgia, the Gulf and San Juan Islands, the Strait of Juan de Fuca, and Puget Sound. Circulation is driven by strong tidal exchange with the Pacific Ocean through the Strait of Juan de Fuca and Johnstone Strait, while substantial freshwater input—particularly from the Fraser River—creates salinity gradients and heterogeneous habitats that support diverse phytoplankton communities. Sampling was concentrated around Galiano Island, British Columbia (48.9236, −123.4415), with additional sites distributed across the Salish Sea. The island lies in a tidally mixed region influenced by oceanic inflow and river discharge, resulting in nutrient-rich conditions and high primary productivity. Intertidal habitats include rocky shorelines, mixed sand and shell beaches, and brackish creek mouths, providing a range of substrates and salinity regimes that support distinct diatom assemblages.

Taxonomic Coverage

No Description available

Temporal Coverage

Project Data

No Description available

The personnel involved in the project:

Sampling Methods

Planktonic diatoms were sampled from the from the water column using 20-µm (occasionally 60-µm) mesh plankton nets. Epiphytic, benthic, and epipsammic diatoms were collected from substrates by swabbing biofilms on eelgrass (Zostera marina), macroalgae, sand, and mud. Samples and associated host substrates were preserved in 4% formalin and stored at 4 °C. For microscopy, material from substrates was brushed into 0.2-µm-filtered seawater and rinsed in distilled water to remove salts. Diatom frustules were cleaned to remove organic material using hydrochloric acid followed by hydrogen peroxide. Samples containing substantial organic debris were digested using heated nitric–sulfuric acid mixtures and then rinsed repeatedly to neutral pH. More delicate taxa were cleaned using hydrogen peroxide alone at room temperature to avoid frustule damage. Cleaned material was mounted on glass coverslips and examined using light microscopy and scanning electron microscopy. In some cases, intact environmental samples (e.g., eelgrass sections or macroalgae) were dehydrated and prepared directly for electron microscopy to observe diatoms in situ. Live diatoms were isolated using micropipettes, rinsed in sterile seawater, and cultured in artificial seawater media under controlled temperature and light conditions. Successful isolates were photographed, preserved as formalin vouchers, and subsampled for DNA barcoding in ethanol or RNAlater. For molecular analyses, samples were concentrated by centrifugation and preserved in ethanol or RNAlater at −18 to −22 °C, with duplicate voucher material retained in the collection. All preserved samples, slides, and electron-microscopy preparations were archived in the project reference collection.

Method step description:

1. Morphological observations were derived from plankton net samples and substrate-associated material (eelgrass, macroalgae, sand, and mud). Cleaned frustules were examined by light and scanning electron microscopy, and identifications were recorded as specimen-based occurrences. Cultured isolates were photographed, preserved as vouchers, and subsampled for DNA sequencing. Environmental DNA and isolate sequencing data were processed using standard bioinformatic workflows. Amplicon reads were quality filtered, dereplicated, and denoised to generate amplicon sequence variants. Taxonomic assignments were made using reference databases and retained only when confidence thresholds were met. All records were mapped to Darwin Core terms.

Additional Metadata