Ocean Wise Canada - Rainy Bay

Restoration Project

Ocean Wise Canada - Rainy Bay

Restoration Objective:

In 2021, Ocean Wise along with partners trialed out-planted green gravel for giant kelp, bull kelp, and sugar kelp, to better understand the effectiveness and efficiency of this method.

Site Selection Criteria:

Divers from Rendezvous Dive Adventures identified suitable sites to conduct in-situ green gravel trials, selecting two transects close to Rainy Bay, British Columbia (Fig. 1) These transects (100m x 1m each) spanned multiple substrates, from large boulders to small pebbles and sandy bottomed areas. They were selected considering depth, freshwater outflow, local knowledge of the area, and convenience for monitoring. Kelp was by-and-large absent in both transects at the onset of the experiment. Green gravel was deployed between late November and early December, 2021 Transect 1 (T1) is located in a moderately sheltered shelf on Cross Point (48.952453, -125.067471). This transect was seeded with bull kelp and sugar kelp. Transect 2 (T3) is located along the northwestern tip of Rainy Bay (48.968656, -125.047997). This transect was seeded with giant kelp and sugar kelp. By December 2021, over 148,000 pieces of gravel seeded with bull kelp, sugar kelp and giant kelp were dispersed onto the two 100 m2 transects. An additional 10 m of this transect serves as a control section, where no green gravel was deployed

Key Reasons For Decline:

Climate Change

Imbalance

Ocean warming

Organisation:

Ocean Wise Canada

Site Observations:

Observation Date

1st Sep 2021 – 30th Sep 2022

Action Summary:

Ocean Wise with partners transplanted approximately 148,000 pieces of gravel seeded with bull kelp, sugar kelp, and giant kelp, dispersed over two, 100 m transects in Rainy Bay, BC. An additional 10 m of this transect serves as a control section where no green gravel was planted.

Lessons Learned:

The green gravel planting process was relatively simple, however, transporting all the pebbles may not be a realistically scalable solution. The giant kelp flourished while the bull kelp did not successfully establish. More exploration in the life stages of bull kelp must be done to understand the reason behind the lack of growth.

Project Outcomes:

This project served as a pilot to trial the effectiveness of green gravel. Biodiversity was high in the locations where giant kelp was planted. Divers observed large schools of perch and juvenile sunflower stars. The results from this project will help guide our future project efforts.

Key Reasons For Decline:

Climate Change

Ocean warming

Imbalance

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Presence / Absence of Kelp

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Transplant Info:
Life Stage:Juveniles

Observation Date

7th Apr 2022 – 31st Jan 2023

Action Summary:

Ocean Wise tested eDNA to understand its effectiveness and efficiency for monitoring biodiversity at kelp restoration sites. We compared the results from the eDNA tests with dive transects.

On April 7, 2022, two SCUIBA divers conducted roving diver fish counts of the two transects. Fish counts, invertebrate and macroalgae abundances were recorded using REEF survey detonations of S = single (1) F = few (2-10) M = many (11-100) A= abundant (100+). Data was compiled into a community composition matrix for each transect, On April 21st, 2022, three eDNA ‘frames’ were deployed per transect (transect replicates)– frames are sealed wire mesh (50cm x 150cm) containing eDNA filters biological replicates, 47mm in diameter) - Bessey et al., 2021. The led-weighted frames were positioned on the ocean floor and kept vertically by Styrofoam floats. A long rope and surface buoy allowed an easy retrieval. These frames were deployed on the 0, 25, and 75 meter marks along transect lines. Frames were deployed and left for 24 hours prior to retrieval (following Bessey et al., 2021). Filters were removed from the frames, preserved in 95% ethanol and shipped to PSEC for analysis by Ocean Wise staff.

Standard eDNA extraction (following current Ocean Wise eDNA protocols). DNA metabarcoding of 18S gene (mitochondrial DNA) to generate fish DNA sequences (total of 18 samples for sequencing). Use 18S FishDB database to create an artificial genome containing DNA barcodes for ~6000 fish and additional marine species such as urchins, snails, and anemones. Utilization of the EPI2ME bioinformatics pipeline to map DNA sequence reads to specific species and generate reports.

Lessons Learned:

This methodology has clearly shown to be promising for the detection of species either alongside dive analysis or on its own. To improve the process, reducing human DNA contamination during the filter deployment and collection process is essential. By doing so this will increase the magnitude of sequencing resources going towards identifying species rather than background noise. In addition, minor improvements/additions to the DNA database used to compare DNA sequences obtained to known sequences would be beneficial. This would increase the sensitivity of the process as well as provide greater confidence in results for species of low abundance and likely reannotate some of the species identified as a closely related species. Lastly, the use of Illumina sequencing at higher depth than what was obtained via Nanopore DNA sequencing would be beneficial for future sample sets. For this initial run, Nanopore sequencing was cost-effective and efficient at obtaining good breadth of species present, but once the eDNA sampling protocol is optimized, the use of Illumina sequencing with higher accuracy and only slightly higher cost would increase the identification of lower abundance species. In terms of in-water methodological adjustments, we recommend deploying a single frame on a central location on each 100m transect (instead of three). The number of filter replicates per frame should be reduced to a single filter of at least three times the size (surface area) of the currently used filters. This should be placed centrally on the sampling frame. This should reduce substantively the costs of analysis.

Project Outcomes:

The intended outcomes of this project include to:

  • Determine baseline fish and invertebrate community composition within transects containing a variety of seeded kelp beds
  • Determine similarity between visual and eDNA monitoring approaches for fish community assemblages
  • Investigate changes in fish and other biodiversity over time with seaforestation activities and kelp ecosystem growth
  • Establish the feasibility and cost-efficiency of eDNA to monitor biodiversity returns associated to kelp restoration and cultivation.

Scientific Paper:

https://ocean.org/app/uploads...Phase-1-external-23JAN23.pdf

Indicator Data:

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