沿岸部では高潮・高波や津波に対する安全・安心確保のため，防波堤や護岸の新設，既設構造物の強靭化が図られてきた．これまで「防災」と「環境」は往々にして対立関係として位置づけられてきたが，今後の海岸保全事業においては共存関係にあることが望ましい．本研究では，沖縄県本部町浜崎海岸に整備された人工リーフに着目し，サンゴの生育状況が近接する構造物に比べて良好な要因を絞り込むことを目的に，水質およびサンゴ被度の調査を実施した．その結果，水温と塩分については，測線，潮汐による顕著な違いは得られなかったが，DOについては，人工リーフに近い表層で高くなる傾向が得られた．サンゴの形態別被度を定量分析した結果，場所によって違いがあり，沖側・南側の被度が高いことがわかった．
In the coastal area, new breakwaters and seawalls have been constructed and existing structures have been strengthened to ensure safety and security against storm surges, high waves, and tsunamis. Although "disaster prevention" and "environment preservation" have often been regarded as conflict relation, it is desirable for coastal protection projects to be coexistent in the future projects. This study focused on the artificial reef at Hamasaki coast in Motobu town, Okinawa Prefecture, and conducted water quality and coral distribution survey with the purpose of clarifying the factors why coral growth status are better than neighboring structures. As a result of water quality survey, there are little differences in water temperature and salinity between the survey lines and the tide conditions, but DO tended to be higher in the surface layer near the artificial reef. Moreover, the results of analyzing the cover rate according to the type of coral indicated that there is a difference depending on the section, and the cover rate of coral on the southern offshore side is higher than the other sections.
浜崎海岸における人工リーフの環境調査およびサンゴ分布特性に関する考察
KU-0020-20191001-01.pdf
(4.52MB)
