Shizuoka Prefecture - Izu Peninsula

Restoration Project

Shizuoka Prefecture - Izu Peninsula

Restoration Objective:

The restoration objective was to restore the abalone fishery that declined following kelp forest loss

Site Selection Criteria:

Kelp was previously present

Cause Of Decline:

Increased sedimentation, turbiditiy, and browsing by herbivorous fish caused the decline of 8000 Ha of kelp forests between 1985 and 2000

Key Reasons For Decline:



Increased turbidity

Scientific Paper

Financial and Institutional Support Are Important for Large-Scale Kelp Forest Restoration

Frontiers in Marine Science, Vol. 535277, 2020.

Site Observations:

Observation Date

15th Jun 1999 – 15th Jun 2010

Action Summary:

Instead of seeding blocks in the field, Ecklonia sporophytes were mass cultured using a deep-sea water circulation system and attached to 2,162 concrete blocks, which were then placed onto natural rocky reefs. Placing the transplants on the blocks elevated the plants off benthos, a place where they are vulnerable to increased turbidity. In addition, the governing bodies paid local fishermen to remove herbivorous fish.

Lessons Learned:

Managing herbivorous fish was essential for the success of the project.

Project Outcomes:

The project successfully restored 870 hectares and as of 2018 the governemnet was considering reopening the abalone fishery.

Area of Restoration (Ha)


Indicator Data:

Transplant Info:
Life Stage:Adult