Environmental DNA (eDNA) is a non-invasive monitoring approach increasingly used to detect marine organisms; however, misunderstandings of the temporal variability in eDNA detection has limited its integration within management decisions. A clearer understanding of the periodicity (e.g., seasonality) and duration (e.g., weeks, months) of species eDNA detection is essential to optimize sampling design and data interpretation. As such, this study aims to provide a representative assessment of optimal eDNA detection windows across diverse taxonomic groups, primers, and geographic regions using eDNA metabarcoding. Coastal marine presence-absence eDNA data were collected along the Northwest Atlantic coast, in the Bay of Fundy, Scotian Shelf, and Baffin Island. eDNA detection window(s) were defined as unimodal, contiguous months having greater than 75% detection probability and were calculated for each taxon for each primer in each region. Most marine species exhibited short eDNA detection windows (1–2 months). The optimal sampling periods and durations were conserved among closely related species, highlighting the importance of considering biological traits when designing and interpreting eDNA studies. Additionally, primer choice influenced the optimal detection periods, with higher seasonal variation in community composition and detection rates using universal COI and 18S primers compared to fish 16S and 12S primers. These results demonstrate that ignoring seasonal variation may cause false negatives, inefficient sampling, and reduced data comparability across independent studies, emphasizing the need for temporal considerations when designing eDNA studies. Thus, we propose a set of guidelines aimed at the development of optimal sampling designs for coastal ecosystems and the interpretation of trends across datasets.
This dataset is for the 16S mitochondrial gene in the Bay of Fundy (BoF) only; Results for the COI, 18S, and 12S markers in the BoF are also available in OBIS.
","language":"eng","citation":{"text":"Lacoursière-Roussel A (2026). DFO Monthly GRDI Survey eDNA metabarcoding (16S) in the Bay of Fundy 2019-2021. Version 1.3. Fisheries and Oceans Canada. Occurrence dataset https://doi.org/10.15468/ddjyvx accessed via GBIF.org on 2026-10-12.","citationProvidedBySource":false},"contactsCitation":[{"key":6964873,"abbreviatedName":"Lacoursière-Roussel A","firstName":"Anaïs","lastName":"Lacoursière-Roussel","roles":["ORIGINATOR"],"userId":[]}],"lockedForAutoUpdate":false,"createdBy":"c98a8d0d-cab2-4506-8c0f-c91a5e4996b9","modifiedBy":"crawler.gbif.org","created":"2025-11-20T19:55:51.868+00:00","modified":"2026-03-30T19:55:36.742+00:00","contacts":[{"key":6964873,"type":"ORIGINATOR","primary":true,"userId":[],"firstName":"Anaïs","lastName":"Lacoursière-Roussel","position":["Research Scientist"],"email":["Anais.Lacoursiere@dfo-mpo.gc.ca"],"phone":[],"homepage":[],"organization":"Fisheries and Oceans Canada","address":["125 Marine Science Drive"],"city":"Saint Andrews","province":"New Brunswick","country":"CA","postalCode":"E5B 0E4","createdBy":"crawler.gbif.org","modifiedBy":"crawler.gbif.org","created":"2026-03-30T19:55:36.715+00:00","modified":"2026-03-30T19:55:36.715+00:00"},{"key":6964874,"type":"CONTENT_PROVIDER","primary":false,"userId":[],"firstName":"Kayley","lastName":"Head","position":["Aquatic Science Biologist"],"email":["kayley.head@dfo-mpo.gc.ca"],"phone":[],"homepage":[],"organization":"Fisheries and Oceans Canada","address":["125 Marine Science Drive"],"city":"Saint Andrews","province":"New Brunswick","country":"CA","postalCode":"E5B 0E4","createdBy":"crawler.gbif.org","modifiedBy":"crawler.gbif.org","created":"2026-03-30T19:55:36.718+00:00","modified":"2026-03-30T19:55:36.718+00:00"},{"key":6964875,"type":"ADMINISTRATIVE_POINT_OF_CONTACT","primary":true,"userId":[],"firstName":"Anaïs","lastName":"Lacoursière-Roussel","position":["Research Scientist"],"email":["Anais.Lacoursiere@dfo-mpo.gc.ca"],"phone":[],"homepage":[],"organization":"Fisheries and Oceans Canada","address":["125 Marine Science Drive"],"city":"Saint Andrews","province":"New Brunswick","country":"CA","postalCode":"E5B 0E4","createdBy":"crawler.gbif.org","modifiedBy":"crawler.gbif.org","created":"2026-03-30T19:55:36.719+00:00","modified":"2026-03-30T19:55:36.719+00:00"}],"endpoints":[{"key":1261309,"type":"DWC_ARCHIVE","url":"https://ipt.iobis.org/obiscanada/archive.do?r=dfo_grdi_bof_16s","createdBy":"c98a8d0d-cab2-4506-8c0f-c91a5e4996b9","modifiedBy":"c98a8d0d-cab2-4506-8c0f-c91a5e4996b9","created":"2026-03-30T19:54:35.423+00:00","modified":"2026-03-30T19:54:35.423+00:00","machineTags":[]},{"key":1261308,"type":"EML","url":"https://ipt.iobis.org/obiscanada/eml.do?r=dfo_grdi_bof_16s","createdBy":"c98a8d0d-cab2-4506-8c0f-c91a5e4996b9","modifiedBy":"c98a8d0d-cab2-4506-8c0f-c91a5e4996b9","created":"2026-03-30T19:54:35.355+00:00","modified":"2026-03-30T19:54:35.355+00:00","machineTags":[]}],"machineTags":[{"key":33015102,"namespace":"crawler.gbif.org","name":"crawl_attempt","value":"43","createdBy":"crawler.gbif.org","created":"2026-10-05T01:14:05.821+00:00"}],"tags":[],"identifiers":[{"key":459523,"type":"UUID","identifier":"b20c6e37-2f4f-44ca-94fa-ccf85ac8ecff","createdBy":"crawler.gbif.org","created":"2025-11-24T12:54:30.652+00:00","primary":false},{"key":459411,"type":"URL","identifier":"https://ipt.iobis.org/obiscanada/resource?r=dfo_grdi_bof_16s","createdBy":"crawler.gbif.org","created":"2025-11-20T19:56:52.929+00:00","primary":false}],"comments":[{"key":46469,"content":"https://github.com/gbif/dataset-category-management/issues/6150","createdBy":"jwaller","modifiedBy":"jwaller","created":"2026-03-12T08:18:20.294+00:00","modified":"2026-03-12T08:18:20.294+00:00"},{"key":45258,"content":"https://github.com/gbif/dataset-category-management/issues/6150","createdBy":"jwaller","modifiedBy":"jwaller","created":"2025-12-01T01:37:21.691+00:00","modified":"2025-12-01T01:37:21.691+00:00"}],"bibliographicCitations":[],"curatorialUnits":[],"taxonomicCoverages":[],"geographicCoverages":[{"description":"Time-series of water eDNA samples were collected from Atlantic coastal regions in Canada at distinct latitudes: Bay of Fundy (44.9424°, -66.8518°). The Bay of Fundy (BOF; area 15,000 km2, depth 100-240 m) is located north of the Gulf of Maine between the shores of New Brunswick and Nova Scotia.","boundingBox":{"minLatitude":-90.0,"maxLatitude":90.0,"minLongitude":-180.0,"maxLongitude":180.0,"globalCoverage":true}}],"temporalCoverages":[],"keywordCollections":[{"thesaurus":"GBIF Dataset Type Vocabulary: http://rs.gbif.org/vocabulary/gbif/dataset_type_2015-07-10.xml","keywords":["Occurrence"]}],"project":{"title":"DFO Monthly GRDI Survey eDNA metabarcoding (16S) in the Bay of Fundy 2019-2021","contacts":[{"type":"OWNER","primary":false,"userId":["http://scholar.google.com/citations?user=hDRu00YAAAAJ&hl=en"],"firstName":"Anaïs","lastName":"Lacoursière-Roussel","position":[],"email":[],"phone":[],"homepage":[],"address":[]}],"awards":[],"relatedProjects":[]},"samplingDescription":{"studyExtent":"Repeated measurements were implemented at multiple levels to support the robustness of species detection patterns: (1) spatially, with samples replicated across multiple stations within each region, (2) temporally, through repeated monthly sampling over three years in the Bay of Fundy, and (3) analytically, through triplicate PCRs. Seasonal variation was therefore incorporated throughout this sampling design.","sampling":"Samples (1 L) were collected once per month from 2-6 stations per region using a Niskin bottle 2-3 m below the surface (BOF: 2 stations, n = 119, July 2019 – November 2021 [excluding February]; HAL: 6 stations, n = 227, October 2021 – December 2022). For each station and sampling event, on average, 2-3 samples were collected from repeated deployments of the Niskin bottle (BOF and HAL: 3 field replicates on average [s.d. 1]. Following a protocol adapted from Walsh et al. (2009), all samples were peristaltically filtered within an hour of collection through a 0.22 μm SterivexTM PVDF pressure filter (Millipore). At least one field negative control of distilled water was filtered for each sampling event. Filters were subsequently preserved at -20 °C in up to 2 mL of Longmire’s lysis preservation buffer until DNA extraction (Williams et al., 2016).\n\nTo minimize risk of cross-contamination during sampling and the filtration process, individual sampling kits were used for each sample (bottles and filter housing sterilized with a 10% bleach solution and new sterilized gloves, syringes, and tweezers). All equipment within the sampling kit was exposed to UV for 30 min.","methodSteps":["Site selection 2. Water collection and eDNA filtration 3. DNA extraction and eDNA metabarcoding 4. Bioinformatics and statistical analyses"]},"countryCoverage":[],"collections":[],"dataDescriptions":[],"dataLanguage":"eng","pubDate":"2026-03-30T00:00:00.000+00:00","maintenanceUpdateFrequency":"AS_NEEDED","maintenanceDescription":"","license":"http://creativecommons.org/licenses/by-nc/4.0/legalcode","dwca":{"coreType":"http://rs.tdwg.org/dwc/terms/Occurrence","extensions":["http://rs.gbif.org/terms/1.0/DNADerivedData","http://rs.iobis.org/obis/terms/ExtendedMeasurementOrFact"],"modified":"2026-07-13T13:58:25.185+00:00"},"category":["eDNA"],"approximateCounts":{"occurrenceCount":14803}}