宮城県女川湾における豊かな海の森づくり活動(平成21年度日本水産工学会秋季シンポジウム「持続的な磯焼け対策の実践に向けて」)

概要

論文の詳細を見る
The reforestation were tried on barren grounds in Onagawa Bay, Miyagi Prefecture according to the Isoyake Taisaku Guideline (Fisheries Agency). Hearing to fishermen clarified the deforestation occurred on three types of bottom, bedrock, boulders and artificial reefs. Kelp culture and transplantation (spore bag, suspended float, caged or exposed on the bottom) revealed that the persistence of barren state is not caused by short of algal propagules nor water quality but due to heavy grazing by herbivores including sea urchins, gastropods and sea hares. To determine the reforestation sites and area sizes, bottom topography and number of participants were considered in addition to fishermen's proposal. Removal of herbivores by citizen divers resulted in the restoration of kelp/Sargassum beds on an exposed bedrock, but not on a sheltered boulder bed. Junior high school students also contributed to map the distribution of urchin barrens, to estimate the amount of kelp growing on shellfish culture ropes and to demonstrate the improvement of gonads by feeding the kelp to empty sea urchins. A committee comprised of industrial, public and scientific members along with fishermen worked well, but further sustainable activities are needed to reduce the barren grounds.
2011-07-15