Restoration Project

San Diego State University - Friday Harbour

Restoration Objective:

This study examined and compared different approaches to restoring bull kelp (Nereocystis luetkeana) populations. It tested the hypotheses that outplanted substrates containing recently settled zoospores or microscopic sporophytes of N. luetkeana would develop with equal success, outplants would have greater survival when elevated above the substratum, and that transplanted juvenile plants (>15cm) could be used to regenerate populations.

Site Selection Criteria:

Sites were selected as areas where N. luetkeana might establish and survive to maturity. Both sites were characterized by serpentine bedrock that is covered in places by shale and silt.

Cause Of Decline:

Anthropogenic disturbances such as shoreline development and sediment loading can reduce or eliminate bull kelp (Nereocystis luetkeana) populations and commercially important species associated with bull kelp.

Key Reasons For Decline:

Water Pollution

Scientific Paper

Restoration of the bull kelp Nereocystis luetkeana in nearshore rocky habitats

L.T. Carney, J.R. Waaland, T. Klinger, K. Ewing, , Marine Ecology Progress Series, Vol. 302.https://doi.org/10.3354/meps302049

Organisation:

San Diego State University

Site Observations:

Observation Date

1st Mar 2003 – 1st Jul 2003

Action Summary:

Nereocystis luetkeana thalli of <15cm were transplanted from wild populations into restoration sites. Juveniles were inserted into rope sections, which were then threaded through a hard plastic clip . The clip was glued to the substrate with epoxy.

Lessons Learned:

This study highlights the importance of testing restoration methods before undergoing large scale restoration. When out-planting microscopic stages, restoration sites where sedimentation rates are high should be avoided. If such sites cannot be avoided, using juvenile plants is recommended.

Project Outcomes:

Nine of the original 32 transplants (28%) survived throughout the study period. These individuals produced and shed sori for at least 80 days, which is a conservative estimate considering sori were first observed on the blades 56 d after transplanting and their production could have been initiated anytime between then and the time of the previous site visit, 37 days after transplanting. The mean number of days the transplants survived was 56 days, although the 9 surviving at the end of the study persisted longer than others.

Key Reasons For Decline:

Water Pollution

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Percent Survival

28.1
%
100
%
Transplant Info:
Source:Wild
Costings:
Cost Year:2003
Cost Currency:USD
Total Cost:1,030
Capital Cost:180
Planning Cost:850

Observation Date

1st Mar 2003 – 1st Jul 2003

Action Summary:

Experimental substrates were seeded either with recently settled zoospores or with microscopic sporophytes and out-planted in the field. Control treatments consistent of experimental substrates with no seed material added.

Lessons Learned:

This study highlights the importance of testing restoration methods before undergoing large scale restoration. When out-planting microscopic stages, restoration sites where sedimentation rates are high should be avoided. If such sites cannot be avoided, using juvenile plants is recommended.

Project Outcomes:

No recruitment was observed at either site on the dishes outplanted in June 2003 during the first and second July 2003 censuses.

Nature of Disturbance:

Over the experimental period, 52.5% of all outplanted cultured dishes were lost at Saddlebag Island. Additionally, sparse fouling macroalgae, chain-forming diatoms and juvenile barnacles were observed on most of the out-planted dishes. A layer of sediment (~1 cm) was present in all dishes. In contrast, only 11% of all outplanted dishes were lost at Cantilever Point. Half of the remaining dishes were clean of all algal growth except for chain-forming diatoms and gastropod grazers, which were observed on a third of the dishes.

Key Reasons For Decline:

Water Pollution

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Percent Survival

0
%
100
%
Costings:
Cost Year:2003
Cost Currency:USD
Total Cost:382
Capital Cost:107
Planning Cost:275