Restoration Project

Kagoshima University - Wakasa Bay

Restoration Objective:

This study examined the successional change in macroalgae biomass on an artificial reef. It also tested the competitive relationship between S. horneri and perennial Sargassum species. The aim of the kelp bed restoration generally was to expand profitable kelp habitat.

Site Selection Criteria:

The artificial reef was constructed next to a natural reef containing Sargassum in order to accelerate colonisation.

Key Reasons For Decline:

Unspecified

Scientific Paper

Subtidal macroalgal succession and competition between the annual, Sargassum horneri, and the perennials, Sargassum patens and Sargassum piluliferum, on an artificial reef in Wakasa Bay, Japan

H. Endo, T. Nishigaki, K. Yamamoto, K. Takeno, , Fisheries science, Vol. 85.https://doi.org/10.1007/s12562-018-1263-9

Organisation:

Kagoshima University

Site Observations:

Observation Date

1st Apr 2008 – 1st Feb 2010

Action Summary:

An artificial reef (250m x 50m) was constructed using natural boulders 1m in diameter. The reef was built next to a natural reef that had Sargassum present in the months where gametophytes are released to accelerate colonisation. Following colonisation of Sphaerotrichia divaricata, Sargassum horneri, Sargassum patens and Sargassum piluliferum, the thalli of these species were removed at different time points, and the growth response of other species was measured.

Lessons Learned:

S. horneri and S. patens/S. piluliferum have a negative effect on the growth of each other in the first year of colonization.

Project Outcomes:

The artificial reef was dominated by the annual brown alga Sphaerotrichia divaricata in July 2008, the annual brown alga Sargassum horneri in March 2009, and the perennial species Sargassum patens and Sargassum piluliferum in February 2010. The removal of S. horneri during autumn 2008 resulted in an increased thallus length in S. patens/S. piluliferum in March 2009, but had no effect in February 2010. Similarly, the removal of S. patens/S. piluliferum during autumn 2008 resulted in an increased thallus length in S. horneri in March 2009, but had no effect in February 2010.

Key Reasons For Decline:

Unspecified

Area of Restoration (In Square Metres)

12,500

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Wet Weight Kelp

5053.521128
g WW/m2
0
g WW/m2
Costings:
Cost Currency:USD