LB 6-47 - Assessing biodiversity differences across nearshore habitats and restoration treatments using marine eDNA

Thursday, August 18, 2022

5:00 PM – 6:30 PM EDT

Located in: ESA Exhibit Hall

Presenting Author(s)

KS

Kate Sheridan

McGill
Montreal, Quebec, Canada

Coauthor(s)

AM

Anya Mueller

McGill University, Canada
ML

Matthew Lemay

Hakai Institute, Canada
EM

Evan Morien

Hakai Institute, Canada
LL

Lynn Lee

Gwaii Haanas Parks Canada, Canada
JS

Jennifer Sunday, PhD

Assistant Professor
McGill University, Canada

Background/Question/Methods:

Environmental DNA (eDNA) metabarcoding is a promising new approach to monitoring conservation impacts in marine systems. However, implementation by ecologists and conservation organizations requires confidence in generated biodiversity data. Preliminary sampling in regions of interest can generate this confidence by demonstrating biodiversity variation across space and habitat type with various conservation management treatments. One region undergoing such management is Haida Gwaii, British Columbia, Canada, including Gwaii Haanas National Park Reserve, National Marine Conservation Area Reserve, and Haida Heritage Site where a kelp forest restoration project using urchin removal was implemented by Gwaii Haanas cooperative management partners - Parks Canada, Council of the Haida Nation, and Fisheries and Oceans Canada. We used eDNA metabarcoding to ask: (1) Do similar nearshore habitat types around Haida Gwaii support similar marine biodiversity, and how does community similarity change between nearshore and offshore, and with distance? and (2) Are eDNA-resolved communities from the kelp restoration site more similar to existing kelp forests or an urchin barren 1-year post-restoration? We surveyed sites in three nearshore habitat types, including a kelp restoration and control site. We amplified the eDNA with metabarcoding primers targeting fish (12S MiFish) and metazoa (COI) and compared restoration eDNA results to visual surveys.

Results/Conclusions:

Environmental DNA revealed that offshore sites had a distinct animal community compared to nearshore sites, which included kelp, seagrass, and unvegetated habitats. Within 200 kilometers, nearshore communities were habitat-specific, but community similarity decreased as a function of distance.

In communities recovered by both markers, the kelp restoration site clustered separately from the control site, indicating some potential differentiation pre- and post-restoration. However neither community overlapped with those from existing kelp habitats elsewhere on Haida Gwaii, indicating the restoration site was not fully restored to healthy kelp forest communities at the time of sampling. However, those changes are expected to take more time. While metabarcoding with environmental DNA captured more species overall, visual surveys captured unique species that were poorly resolved with the markers used, such as members of the rockfish genus Sebastes. Our findings suggest that eDNA may be able to help us evaluate community recovery from restoration efforts over the multiple years that community change is expected to take following restoration efforts.