Restoration Project

Pukyong National University - Ikata

Restoration Objective:

The objective of restoration efforts was to regenerate kelp beds, which are not only commercially important in themselves but also play an important role in spawning, breeding, and feeding grounds for many kinds of fish, shellfish, lobster, and other important fisheries resources.

Key Reasons For Decline:

Multiple

Scientific Paper

Ecology of seaweed beds on two types of artificial reef

C.G. Choi, Y. Takeuchi, T. Terawaki, Y. Serisawa, Masao M., C.H. Sohn, , Journal of Applied Phycology, Vol. 14.https://doi.org/10.1023/A:1022126007684

Organisation:

Pukyong National University

Site Observations:

Observation Date

16th Feb 1991 – 1st Jun 2001

Action Summary:

Two artificial reefs of different sizes were placed on sandy substrates at 8m (Site A), 10m (Site B) and 13 m (Site C) depth in Muronohana, Ikata, Japan, and observed monthly or bimonthly from February 1999 to June 2001. The "M" type reefs installed at sites A and B had a volume of 3.47m3 (2.5 × 1.5 × 1.25m). The “RF type” reef at sites A and C had a volume of 4.8m3 (2×2×1.2m).

Lessons Learned:

There was data on artificial reef sites at varying depths. There was not a clear description of artificial reef structures (e.g. materials) or sites (e.g. sandy, rocky etc).

Project Outcomes:

A total of 38 seaweed species were identified on the reefs over the study period. Brown algae such as Sargassum spp. and Ecklonia kurome covered over 20% of the reef during the winter season. Enteromorpha intestinalis and Colpomenia sinuosa were the primary dominants in spring. The number of seaweed species at all the sites gradually increased in winter. Each reef reached a climax stage of Sargassum spp., Ecklonia kurome and Padina arborescens within 18 months. The settlement of kelp, such as E. kurome, was promoted by reduced sand cover as a result of turbulence.

Key Reasons For Decline:

Multiple

Area of Restoration (In Square Metres)

14

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Kelp Cover

17.75
%
0
%
Costings:
Cost Currency:USD

Observation Date

16th Feb 1991 – 1st Jun 2001

Action Summary:

Two artificial reefs of different sizes were placed on sandy substrates at 8m (Site A), 10m (Site B) and 13 m (Site C) depth in Muronohana, Ikata, Japan, and observed monthly or bimonthly from February 1999 to June 2001. The "M" type reefs installed at sites A and B had a volume of 3.47m3 (2.5 × 1.5 × 1.25m). The “RF type” reef at sites A and C had a volume of 4.8m3 (2×2×1.2m).

Lessons Learned:

There was data on artificial reef sites at varying depths. There was not a clear description of artificial reef structures (e.g. materials) or sites (e.g. sandy, rocky etc).

Project Outcomes:

A total of 38 seaweed species were identified on the reefs over the study period. Brown algae such as Sargassum spp. and Ecklonia kurome covered over 20% of the reef during the winter season. Enteromorpha intestinalis and Colpomenia sinuosa were the primary dominants in spring. The number of seaweed species at all the sites gradually increased in winter. Each reef reached a climax stage of Sargassum spp., Ecklonia kurome and Padina arborescens within 18 months. The settlement of kelp, such as E. kurome, was promoted by reduced sand cover as a result of turbulence.

Key Reasons For Decline:

Multiple

Area of Restoration (In Square Metres)

14

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Kelp Cover

40.75
%
0
%
Costings:
Cost Currency:USD

Observation Date

16th Feb 1999 – 1st Aug 2000

Action Summary:

An iron artificial reef (4.5m x 4.1m x 2.5m, 45.38m3 and 3.2 ton) was placed on a sandy bottom at 8m depth in February 1999. Twelve different types of substrata (40x60 cm) made up of steel, concrete, wood and stone were fixed on the roof of the artificial reef.

Lessons Learned:

Has categories for coverage, but success was assessed instead. Seaweed attachment was similar between materials on the artificial reef.

Project Outcomes:

Within one month, diatoms dominated on all substrata with cover of approximately 100%. Enteromorpha intestinalis and Colpomenia sinuosa dominated on the reef within three months after installation. Seaweed communities on the reef decreased during the summer. In the winter, the seaweeds on the reef recovered. Sargassum spp., Ecklonia kurome and Padina arborescens dominated on each substratum after one year. Seaweed communities on the artificial reef were similar to those on the rocky substratum around the artificial reef and also similar on different substrata covering the iron artificial reef. In February 2000, 12 months after the placement of the artificial reefs, C. sinuosa reappeared, and coverage was increasing on almost all reefs, about 10-80% coverage.

The loss of kelps on coasts worldwide has led to widespread barren grounds characterised by a low abundance or diversity of marine organisms and seaweeds. These areas also have less fishery resources such as abalone, fish and seaweeds.

Key Reasons For Decline:

Multiple

Scientific Paper:

C.G. Choi, M. Ohno, C.H. Sohn, , Algae, Vol. 21.https://doi.org/10.4490/algae.2006.21.3.305

Area of Restoration (In Square Metres)

18.5

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Presence / Absence of Kelp

Costings:
Cost Currency:USD

Observation Date

1st Apr 1999 – 1st Feb 2000

Action Summary:

Spore bags containing fertile Sargassum spp. and Ecklonia were installed on the top of an iron artificial reef and a natural rock habitat site as a control. Twelve different plates with varying materials (wood, steel, iron, pebble, concrete, zeonite) were installed on the bedrock, and the percentage cover of Sargassum and Ecklonia recruits was measured.

Lessons Learned:

Data is presented for a variety of plates attached on the artificial reef.

Project Outcomes:

Recruits appeared after four months.
Kelp forests are not only commercially important resources, they also provide breeding grounds for many fish and invertebrates. Ecklonia and Eseina kelp species are restricted to warm waters, and are declining in some areas due to human activities.

Key Reasons For Decline:

Multiple

Scientific Paper:

C.G. Choi, Y. Serisawal, M. Ohno, C.H. Sohn, , Algae, Vol. 15.http://marineagronomy.org/sit...ificial%20Seaweed%20Beds.pdf

Area of Restoration (In Square Metres)

95

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Kelp Cover

25.91666667
%
0
%
Costings:
Cost Currency:USD