Details:

Journal Title:
Diversity and Distributions
Personal Author:
Keller, Stephen R. ; Hilderbrand, Robert H. ; Shank, Matthew K. ; Potapova, Marina
Keller, Stephen R. ; Hilderbrand, Robert H. ; Shank, Matthew K. ; Potapova, Marina Less -
NOAA Program & Office:
OAR (Oceanic and Atmospheric Research) ; Sea Grant
OAR (Oceanic and Atmospheric Research) ; Sea Grant Less -
Sea Grant Program:
PENN (Pennsylvania Sea Grant)
Description:
Aim

Establishing the distribution and diversity of populations in the early stages of invasion when populations are at low abundance is a core challenge for conservation biologists. Recently, genetic monitoring for environmental DNA (eDNA) has become an effective approach for the early detection of invaders, especially for microscopic organisms where visual detection is challenging. Didymosphenia geminata is a globally distributed freshwater diatom that shows a recent emergence of nuisance blooms, but whose native versus exotic status in different areas has been debated. We address the hypothesis that the distribution and genetic diversity of D. geminata in eastern North America is related to the recent introduction of non-native lineages, and contrast that with the alternative hypothesis that D. geminata is cryptically native to the region (i.e. at low abundance) and only forms nuisance blooms when triggered by a change in environment.

Location

The Mid-Atlantic region of North America.

Methods

We analysed 118 stream samples for D. geminata eDNA, validated our results for a subset of sites using direct visual enumeration by microscopy and used molecular cloning to sequence D. geminata from two sites where eDNA was detected.

Results

(1) D. geminata eDNA was detected at seven spatially unique sites, six of which were previously documented to contain recent D. geminata blooms. (2) Sites where D. geminata eDNA was detected exhibited no difference in environmental conditions compared to sites with no-detected D. geminata eDNA. (3) Sequencing of D. geminata eDNA showed that blooms were composed of multiple genetic lineages, closely related to those sampled elsewhere across the globe.

Main conclusions

We interpret these results as most consistent with the hypothesis that D. geminata is an exotic invader in the Mid-Atlantic region, still in its early stages of invasion; thus, genetic monitoring and management efforts may still be effective at controlling its spread.


Keywords:
[+]
Algal Blooms Diatoms DNA
Source:
Diversity and Distributions 23(4): 381-393, 2017
DOI:
https://doi.org/10.1111/ddi.12536
Sea Grant Document Number:
PENN-R-17-001
Document Type:
Journal Article
Place as Subject:
North America
Rights Information:
Other
Compliance:
Library
Main Document Checksum:
[+]
urn:sha256:43a311b51ae429ffb2d32379b0ff754ffc442b10e4f668e6033e73db5fb487b1
Download URL:
https://repository.library.noaa.gov/view/noaa/43792/noaa_43792_DS1.pdf
File Type:

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