Restoration Project

East Sea Regional Fisheries Research Institute - Gangwon

Restoration Objective:

The objective of this study was to determine the optimal plant size and timing for transplantation of E. cava seed-stock using the modified artificial stepped reef structure.

Site Selection Criteria:

A barren ground was selected for artificial reef placement.

Cause Of Decline:

Barren grounds are currently expanding in Korea as the result of destruction of seaweed habitats due to overharvesting and increases in levels of herbivory (including by sea urchin and abalone), sea temperatures and industrial pollution.

Key Reasons For Decline:

Multiple

Scientific Paper

Size determination of Ecklonia cava for successful transplantation onto artificial seaweed reef

Y.D. Kim, J.M. Shim, M.S. Park, J.P. Hong, H.I. Yoo, B.H. Min, J.K. Kim, , Algae, Vol. 28, p.365.https://doi.org/10.4490/algae.2013.28.4.365

Organisation:

East Sea Regional Fisheries Research Institute

Site Observations:

Observation Date

15th Mar 2007 – 15th Dec 2007

Action Summary:

A modified artificial stepped reef structure was created with a total of 14 units (3m length × 3.5m width × 1.1m height) weighing 12.7 tonnes. These units were deployed on the bedrock of a barren ground at 7-8m depth using a barge. Ecklonia cava sporophytes were transplanted onto the artificial step seaweed reefs in February (1-2 cm), March (5-10 cm), and April (20-30 cm in length). Blade length, width and density were measured monthly from February to December 2007 by scuba divers.

Lessons Learned:

Small Ecklonia cava plants (5-10cm) grow more rapidly than large plants (20-30cm). Survival of both is similar, and much higher compared to sporophytes.

Project Outcomes:

Ecklonia cava sporophytes that were <1cm in length died within one month of being transplanted to the artificial reef. This was likely due to high numbers of sea urchins. Similarly, Laminaria species were mostly destroyed by sea urchin grazing, except blades of 5-10cm length transplanted in March survived and grew on the reef. Both the size classes of 5-10cm and 20-30cm length grew until June, and size reductions were reported from September. From October, the 5-10cm size class began to grow more rapidly than the 20-30cm size class. Survival rate was similar between both size classes.

Key Reasons For Decline:

Multiple

Area of Restoration (In Square Metres)

350

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Percent Survival

16
%
100
%
Costings:
Cost Currency:USD